Bronco Forum - Full Size Ford Bronco Forum banner

1 - 20 of 20 Posts

·
Registered
Joined
·
25 Posts
Discussion Starter #1
Hey guys. I'll try and keep this short I'm losing my mind on this one.
It's not a Bronco. 94 F150 5l 4x4 w/E4OD
Truck was bought a year ago. Ran great until it started having a weird delay in shifting between gear change. But still ran great.
One morning start it up. Put it in D and stalls dead. Start it up again. Can put it in reverse and 1 and it drives perfectly smooth. As soon as I pass over D or 2 theres is a dip in battery voltage and engine almost stalls out. Put it in D or 2 and it stalls. Run memory and Koe test and pull only a 629 code. Electrical fault to TCC.
I had to do rear crank seal and oil pan seal as well as t case seals etc and other work. I bought new shift solenoid pack to swap out the old one. Opened trans pan, drained fluid and changed the solenoid pack and filter etc
Inspecting the harness to the pack, the wires had been cased in dirt but they were exposed some frayed and looked like they had actually been in contact with eachother on a lot of them.
Pulled the harness and wired in a replacement harness for solenoid pack. Tested the harness for continuity and short to ground. Checked it again using wiring diagram pin to pin to make sure I didnt confuse wire colors. Gtg. Disconnect the PCM and check the tcc solenoid purple yellow wire from pcm to fender harness. Continuity and no short. Plug the harness into the fender connector and check continuity and short to ground on the whole system. From pcm to solenoid harness. Gtg. Plug pcm back in and turn on aux power and test the solenoid harness for voltage. Its getting power.
Did all the major mechanical work on the truck then reinstalled the trans. Filled up fluid.
Plugged harness back in.
Fire up the truck. Put it in D and fucking dead again.....629 code only.....runs in 1 and R all day long.
I'm fucking stumped.

The only thing I can fathom is that because the shift solenoid goes directly to PCM with no fuse or breaker, the dirt could have shaken loose, wires made contact above the harness and I sent 12v to the pcm up the TCC line to the PCM and blew the diode or capacitor in the PCM when I fired it up in P that morning.

I have posted this on the Ford truck forum and I'm not getting any new advice.
Would it be a good assumption at this point to pull the pcm and check it for a blown or burnt capacitor? Is there a way to test the PCM itself on this line?

Any advice on this would be greatly appreciated.
 

·
Super Moderator
Joined
·
26,090 Posts
Yo 94OneFitty,
Welcome!
Code 629 first.

DTCs 91/621, 92/622, 93/626, 94, 629, 641 and 652 indicate solenoid did not change state when requested by the Powertrain Control Module (PCM).
DTC 566 or 629 indicates the CCO or SS3/4-4/3 did not change state when requested by the PCM.
Possible causes:
Damaged solenoid/assembly.
Open or shorted harness (internal/external).
Damaged PCM.
Note: Do not use a STAR Tester for this step. Use a VOM or DVOM.

miesk5 Note; this set of tests includes use of Ford's old Break-Out Box; so, as I mentioned in another thread here; In place of the break-out box, go to the EEC connector pin instead; substitute EEC connector pin Number for breakout box number. Using;
EEC IV Connector Pin Diagram
Source: by Ryan M at

EEC IV Connector Pin LEGEND Bronco & Ford Truck & Van: 4.9, 460, 5.0, 5.8;
Source: by Ryan M (Fireguy50) at Ford Fuel Injection

Disconnect electrical connector on the speed control servo, if equipped.
VOM/DVOM on 20 volt scale.
Connect negative test lead to STO circuit at Data Link Connector (DLC) and meter positive test lead to B+.
Jumper STI circuit to SIG RTN at the DLC.
miesk5 Note, here is the DLC PIN DIAGRAM;


Perform Key On Engine Off Self-Test until Continuous Memory DTC have been displayed.
VOM/DVOM will indicate less than 1.0 volt when test is complete.
Depress and release throttle.
Does voltage increase?
Yes REMAIN in Output State DTM. GO to TC2.
No DEPRESS throttle to WOT and RELEASE. If STO voltage does not go high, PERFORM Pinpoint Test Step QC1. Leave equipment hooked up.

TC2 CHECK SOLENOID ELECTRICAL OPERATION
Key on, engine off.
Disconnect transmission connector.
Using a mirror, inspect both ends of the connector for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.
Refer to the schematic and table of this Pinpoint Test.
Connect VOM/DVOM positive test lead to VPWR circuit and negative test lead to solenoid circuit of the transmission vehicle harness connector.
miesk5 Note, here is the 95 E4OD Solenoid Connector pin diagram;

VOM/DVOM on 20 volt scale.
While observing DVOM, depress and release throttle several times to cycle solenoid output ON and OFF.
Does the suspect solenoid output voltage change at least 0.5 volt?
Yes RECONNECT connector. REFER to the Transmission Group in the Service Manual.
No REMOVE jumper wire. GO to TC3.

TC3 CHECK CONTINUITY OF SOLENOID SIGNAL AND VPWR HARNESS CIRCUITS
Key off.
Solenoid transmission connector disconnected.
Disconnect Powertrain Control Module (PCM). Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.
Install breakout box, leave PCM disconnected.
Refer to schematic and table in this Pinpoint Test.
Measure resistance between suspect PCM signal output pin at the breakout box and signal output pin at transmission vehicle harness connector.
Measure resistance between Test Pin 37/57 at the breakout box and VPWR pin at transmission vehicle harness connector.
Is each resistance less than 5.0 ohms?
Yes GO to TC4.
No SERVICE open circuit(s). REMOVE breakout box. RECONNECT all components. RERUN Quick Test

TC4 CHECK SOLENOID HARNESS FOR SHORTS TO POWER OR GROUND
Key off.
Breakout box installed, PCM disconnected.
Transmission connector disconnected.
Refer to schematic and table in this Pinpoint Test.
Measure resistance between PCM signal output pin and Test Pin 37/57 at the breakout box.
Measure resistance between PCM signal output pin and Test Pins 40/60 and 46 at the breakout box and chassis ground.
Is each resistance greater than 10,000 ohms?
Yes REFER to Service Manual, Transmission Diagnosis for internal harness and solenoids. IF OK, REPLACE PCM. REMOVE breakout box. RECONNECT all components. RERUN Quick Test.
NoSERVICE short circuits. REMOVE breakout box. RECONNECT all components. RERUN Quick Test.

I can't find QC1. Will look for it later.
⊙⊙⊙

Find out if speed control, if equipped, recall work completed by a dealership. Call local dealer or register and view status @ https://owner.ford.com; or @ Recalls Look-up by VIN (Vehicle Identification Number) ... have VIN ready.
"Summary: ON CERTAIN PICKUP TRUCKS, PASSENGER VEHICLES, SPORT UTILITY VEHICLES, AND MOTOR HOMES CHASSIS, THE SPEED CONTROL DEACTIVATION SWITCH MAY, UNDER CERTAIN CONDITIONS, LEAK INTERNALLY AND THEN OVERHEAT, SMOKE, OR BURN. THIS COULD RESULT IN AN UNDERHOOD FIRE."
To confirm current status, use this guide by jowens1126 @ 93 & 94-96 Cruise Control Recalls Repair
note that the 93 recall is different than 94-96

For any questions or to chat about it's planned modifications or build, it's better to post each seperately in Noobie Bronco Tech Questions. Flame free zone. This will get more attention and you can build up your post count to get into other sections such as Bronco and Ford Parts/Accessories (75 posts required to view).

To save you time and for better responses, please fill out your Signature with location, F 150, year, engine size, transmission type, transfer case type (manual or electric shift), locking hub type (automatic or manual) info & major mods such as a Lift, etc. .
From the navigation, near the upper right-hand corner, click on your avatar and then select “Account Settings” from the drop down menu.


From your “Account Settings” page you will then see more navigation option of the left side. Select “Signature”.


Now you can simply enter your signature information in the text editor and click save.

Our Forum faqs @ FAQ
Includes for example:
How To Upload Images To Posts & How to Use Search
See more tips!

Baba Looey's Favorite FSB Links (lots and lots of tech links, some are same for the F 150) @ Baba Looey's Favorite FSB Links (lots and lots of tech links) ...

Free registration for some wiring diagrams (86 through 96) and Technical Service Bulletins, (80 through 96), same as by Ford @ BBB Industries- Premium Alternators, Starters, Power Steering Products | TSB's & Wiring Diagrams

➡ Try to find time to participate and VOTE in our Full-Size of the Month (F.O.T.M.) & Full-Size of the Year (F.O.T.Y.) Contests @ F.O.T.M Voting
You will get ideas by those competing. Also see the prizes! They are awesome as compared to other sites' "contests"!
VOTE in the ongoing Full-Size of the Year (F.O.T.Y.) Contest.
Al
 

·
aka: kemicalburns
Joined
·
7,844 Posts
open up the computer and take a peak. it very well could be toast and needs replaced. you did install that same year solenoid pack? what about your MLPS solenoid?
 
  • Like
Reactions: Chris Czaja

·
Registered
Joined
·
87 Posts
open up the computer and take a peak. it very well could be toast and needs replaced. you did install that same year solenoid pack? what about your MLPS solenoid?
I agree. EEC is easy to take out, open up and look at. Wish I had done it much sooner.
 

·
Registered
Joined
·
25 Posts
Discussion Starter #5 (Edited)
open up the computer and take a peak. it very well could be toast and needs replaced. you did install that same year solenoid pack? what about your MLPS solenoid?
Yes solenoid pack was a 94 and compared side by side with the original before installation.
I did verify the Neutral safety switch connector harness had proper continuity and no short to grounds all the way back to the pcm when I had the entire harness out and was troubleshooting it. Also this issue started before I removed anything at all. Up to that point I had not had any real issues until the morning after I drove it day prior. Then bang 629, dip in power and engine dies in D and 2.

If the neutral safety switch was defective would that be throwing only a 629 code with the symptoms I have? All the research I've done says no at this time. I have ruled out the harness complete.
I think I'm going to apply 12v to the old solenoid pack TCC solenoid and see if it actuates. If it does then I'm likely going to pull the computer itself.

I'm trying to decipher the first post with all the electrical testing instructions now as well.
I'll have to start from the top. The test of the TCC purp/yell wire with the jumper on the obd connectors I have not tried. That should tell me my shift solenoid TCC is working or not in the installed pack if I'm reading it correctly.
I've already tested the entire circuit from pcm pin to trans harness for continuity and short to ground and found nothing.
I think I may have fried the TCC solenoid or the pcm. I'll run the diagnostic koeo test on the tcc solenoid and rule that out. I think I'll apply 12 volts to the old TCC solenoid pack as well and see if it actuates. If they're both good then it literally cant be anything else other than the pcm right?
 

·
Registered
Joined
·
25 Posts
Discussion Starter #6
Miesk5,

I just spent time understanding that whole diagnostic.
Thank you brother! That's the holy grail I needed! I can rule out the installed solenoid pack, the old one as well and get it down 100% to a pcm fault. Amazing!
I already did the 3 and 4 test when I checked whole system bundle from pcm to trans harness but I'll do it again anyways.
I'll report back! Thanks guys!
 

·
Registered
Joined
·
25 Posts
Discussion Starter #7 (Edited)
Well! Live report. Ran through step 1. Confirmed the test system was sending voltage. Had a good 12v read plugged into the OBD boot.

Pulled the trans harness and removed the mlps off the trans. Pulled the harness into the cab, probed positive lead of VOM to the red power wire on the harness and negative to the OLD solenoid pack I removed. VOM read .10 to .13v on 20v setting as a base. Throttle all the way down and up a couple times. NO CHANGE in voltage at all. Tested other solenoids and same results!

I already tested every circuit on the whole harness after repairing the trans plug harness. So I know theres no shorts and good continuity from PCM all the way to harness from before. I'm a do it again anyways but I'm now 100% certain it's the PCM!

I get it why you do step 1 first. The voltage spike from the fuel relay and STO pins on the obd block confirms the throttle is sending voltage to the system in test mode!

One question for step 2, when I'm hooking my pos lead to the power wire in my trans harness and the neg lead to my tcc solenoid pin on my pack it is reading about .09 to .13 v on the 20 v setting, I throttle the pedal and I get no increase in voltage on the VOM. The test says then go to the wiring harness tests. Does this 100% confirm that the solenoid is not faulty? Or am I reading that part of the test wrong?
Meaning that if I got a .5+ change in voltage the solenoid would be defective?
I tested all the solenoids on my original AND the one installed now and they all showed NO voltage change at all.
 

·
Registered
Joined
·
25 Posts
Discussion Starter #9
Last two trucks I've have with this same exact issue, a PCM change fixed it.
All,

I wanted to follow up on this as I hate following threads and then just die with no info as to what the solution was.

So 629 code throws.
No other codes
Truck will drive in 1st gear and reverse but stalls dead in 2nd snd D
Also power supply drop hard when shifting from park or neutral to 1st gear.

First pull the harness from the e40d trans.
inspect it for corrosion and crossed wires. If they are, pull the whole harness and pin to pin connector test for continuity and short to ground.
if that's good then check the resistance on the shift solenoid pack across the pins.
if that's good, put the the vehicle in test mode and get your reference voltage and apply the test to the solenoid pack pin terminals and throttle the gas pedal to check for faults in the solenoid pack.

IF THAT IS ALL RULED OUT and no issues, then you 100% have a fried pcm!
I bought a new one after running these diagnostics and doubting myself.
Installed the new refurbed pcm today and the truck runs and shifts like new. Also snapped the engine awake a bit too.

Problem resolved. I think my power supply wires crossed at least 2 or 3 other of the solenoid pack wires including the two gear shift solenoids and fried the pcm.

It makes sense in the end as the 629 is an electrical power supply fault to the tc clutch solenoid. The truck rolling in 1st snd R ruled out anything wrong with the trans or the torque convertor.

Thanks for all the help with this guys. To say i learned a lot would be a huge understatement.

Cheers
 

·
~*~*~*~*~*~*~
Joined
·
10,098 Posts
We truly appreciate you coming back and finishing the thread with the fix! Thanks!
 

·
Registered
Joined
·
25 Posts
Discussion Starter #11
No thank you guys! Sincerely! This was one of the most frustrating snags I ever hit working on a vehicle and I learned a literal mountain of info on the electrical system of these old beasts and diagnostic theory in general.

Again this site is Hobby Mechanic Mecca and you guys are awesome.
 

·
Registered
Joined
·
13 Posts
This is the exact problem I'm having!!!! Can you help me? I'm not real fluent in multi-meter language. I just borrowed one to do this test but I'm unsure how all this works. HELP!!!


QUOTE="94OneFitty, post: 7286682, member: 223726"]
No thank you guys! Sincerely! This was one of the most frustrating snags I ever hit working on a vehicle and I learned a literal mountain of info on the electrical system of these old beasts and diagnostic theory in general.

Again this site is Hobby Mechanic Mecca and you guys are awesome.
[/QUOTE]
 

·
Super Moderator
Joined
·
26,090 Posts
Yo jsumm,
if you have Diagnostic Trouble Code 629, and have same "The truck rolling in 1st snd R",

suggest you pull and inspect the PCM, AKA EEC IV, Computer.
See removal by jowens1126 @ Engine Swap for '95

Here are some PCM KILLER perpetrators and other causes:
Old leaky capacitors, see swapped EEC and no more codes by jowens1126
Smell around the PCM. If it smells like dead fish, it's bad.
Burned PCM printed circuit board circuits and resistors, etc.(brown burn marks).
Water damage from cowl leaks, ESPECIALLY if you you have wet carpet or mat near driver kick panel;
or on PCM Connector due to a bad hood seal near cowl panel, viewable with hood up.
Corrosion or damage due to moisture is one of the main reasons for failure. Corrosion can enter through the wiring harness and moisture can enter by a failure in the seals in the PCM itself. This happens over a period of time (5 to 10 years) due to exposure to the elements.
The alternator could be generating an AC voltage spike due to bad diode(s) or supply Voltage Overloads.
I recommend bench-testing the alternator for voltage output and AC voltage ripple.
Thermal stress due to excessive heat and excessive vibration that causes sensitive parts to fail.
Bronco was jump started on reverse polarity.

Internally
Overheated PCM.
Bad Intel 8061 chip or bad Intel 8361 memory chip
Bad Internal Voltage Regulator, see Wayback Machine by Ryan M
 

·
Registered
Joined
·
13 Posts
Any help, I'm trying to understand it now. I am unsure if it's my pcm. I have the exact same issue as you. help!


Miesk5,

I just spent time understanding that whole diagnostic.
Thank you brother! That's the holy grail I needed! I can rule out the installed solenoid pack, the old one as well and get it down 100% to a pcm fault. Amazing!
I already did the 3 and 4 test when I checked whole system bundle from pcm to trans harness but I'll do it again anyways.
I'll report back! Thanks guys!
 

·
Registered
Joined
·
13 Posts
Okay. I checked my pcm. I had a couple burnt spots. I replaced the resistors but I'm still having the same trouble. You think the whole board is bad?
168864



Yo jsumm,
if you have Diagnostic Trouble Code 629, and have same "The truck rolling in 1st snd R",

suggest you pull and inspect the PCM, AKA EEC IV, Computer.
See removal by jowens1126 @ Engine Swap for '95

Here are some PCM KILLER perpetrators and other causes:
Old leaky capacitors, see swapped EEC and no more codes by jowens1126
Smell around the PCM. If it smells like dead fish, it's bad.
Burned PCM printed circuit board circuits and resistors, etc.(brown burn marks).
Water damage from cowl leaks, ESPECIALLY if you you have wet carpet or mat near driver kick panel;
or on PCM Connector due to a bad hood seal near cowl panel, viewable with hood up.
Corrosion or damage due to moisture is one of the main reasons for failure. Corrosion can enter through the wiring harness and moisture can enter by a failure in the seals in the PCM itself. This happens over a period of time (5 to 10 years) due to exposure to the elements.
The alternator could be generating an AC voltage spike due to bad diode(s) or supply Voltage Overloads.
I recommend bench-testing the alternator for voltage output and AC voltage ripple.
Thermal stress due to excessive heat and excessive vibration that causes sensitive parts to fail.
Bronco was jump started on reverse polarity.

Internally
Overheated PCM.
Bad Intel 8061 chip or bad Intel 8361 memory chip
Bad Internal Voltage Regulator, see Wayback Machine by Ryan M
Yo jsumm,
if you have Diagnostic Trouble Code 629, and have same "The truck rolling in 1st snd R",

suggest you pull and inspect the PCM, AKA EEC IV, Computer.
See removal by jowens1126 @ Engine Swap for '95

Here are some PCM KILLER perpetrators and other causes:
Old leaky capacitors, see swapped EEC and no more codes by jowens1126
Smell around the PCM. If it smells like dead fish, it's bad.
Burned PCM printed circuit board circuits and resistors, etc.(brown burn marks).
Water damage from cowl leaks, ESPECIALLY if you you have wet carpet or mat near driver kick panel;
or on PCM Connector due to a bad hood seal near cowl panel, viewable with hood up.
Corrosion or damage due to moisture is one of the main reasons for failure. Corrosion can enter through the wiring harness and moisture can enter by a failure in the seals in the PCM itself. This happens over a period of time (5 to 10 years) due to exposure to the elements.
The alternator could be generating an AC voltage spike due to bad diode(s) or supply Voltage Overloads.
I recommend bench-testing the alternator for voltage output and AC voltage ripple.
Thermal stress due to excessive heat and excessive vibration that causes sensitive parts to fail.
Bronco was jump started on reverse polarity.

Internally
Overheated PCM.
Bad Intel 8061 chip or bad Intel 8361 memory chip
Bad Internal Voltage Regulator, see Wayback Machine by Ryan M
 

·
Registered
Joined
·
25 Posts
Discussion Starter #16
Okay. I checked my pcm. I had a couple burnt spots. I replaced the resistors but I'm still having the same trouble. You think the whole board is bad? View attachment 168864
I wont pretend to be a pro at circuit boards or electronics board repairs at all here.
What I can tell you, is that if you have done everything in this thread ie:
Checked the harness to shift pack for rott and falling apart.
Fixed the harness if its fried.
Pin to pin check for continuity and short to ground end to end on the harness and then harness plug in to PCM plug in.
Voltage test on the shift solenoid pack pins.
Then there is NOTHING else it can possibly be.
If your trans goes into reverse and 1st gear and rolls then your pump and torque convertor are working ie your trans is not the issue.

When I did this process I opened up my pcm which I knew was now the culprit. It looked fine. As in brand new 100% fine.

Swapped it for a warranty refurbed one. Bam! Fixed. Been rolling like a champ since.

Also if you really really need to drive the truck still until you get a new PCM, cut the purple wire with yellow pin stripe in the wiring harness just after the pcm to square plug in on fender under the hood. You'll be able to drive in D no problem.
It will completely disable the power to the Torque Convertor Clutch solenoid. Basically your torque convertor will be free spinning constantly without being slowed down by the pulsing TCC solenoid (actuated by the PCM circuit the purple yellow wire goes to).

People say it will overheat and cook your trans. It probably does increase the temp of the fluid above optimal temp. For sure. I drove my truck with the wire cut for over a month waiting for my new PCM to arrive. Its fine. Swapped the pcm, connected the wire and bam, she was good to go. Been driving it for 8 months and good to go!

Dont start poking around in the box too much brother, you'll drive yourself crazy. Find a shop that refurbs them, see if you can buy a new one refurbed and give them your old one for a core return.

Did you run all the diagnostics above?
It can only be the PCM if you did. Legit.
 

·
Registered
Joined
·
25 Posts
Discussion Starter #17
In R and 1st gear there is essentially a mechanical bypass in the trans valve body when you select those ranges that unlocks the tc clutch by fluid pressure vice electronic signal to the tcc solenoid in the trans shift pack. Thats why you can drive fine in R and 1st.

When you put the selector in D, the trans does not autmatically force it to unlock. Your PCM sends power through the purple yellow cable to the tc clutch solenoid. The solenoid then actuates and unlocks the TC clutch to allow the TC to turn with the engine crank/flywheel.

If its not happening and its throwing 629 its electrical fault to tcc solenoid.
Ie power is NOT getting to and actuating the tcc solenoid (in the shift pack with the other solenoids that actuate gear changes etc). Your Torque convertor is staying locked in place and cant turn.

Engine tries to turn but the TC stays locked and engine stalls.

Its a power supply problem at core. Why power is not getting to it is either:
Fried wiring harness at shift pack.
Short to ground or no continuity in one of the wires in the harness.
Tcc solenoid is fried (voltage test with truck in test mode can verify this)
Or the pcm is fried.

My suspicions on the cause is the harness at the shift pack gets ratty and stripped, wires get crossed. Maybe vehicle constant power crosses TCC wire or others and sends voltage back to pcm and fries that board circuit etc
Could be moisture like Miesk said too causing slow corrosion. I find it odd how it always seems to affect that specific circuit though so frequently and not anything else.

My truck had a soggy floor driver side from a bad leak in the windshield top.
Floor was rotted out bad (Im swapping the cab now as the rebuild continues). My harness was completely fucked too. Like every wire stripped and most in contact and also a nice thick dense wet layer of mud encasing it all lol. Maybe a combination of both over time hahaha I learned a lot wrestling with this bastard of a problem and I came out way wiser and confident thanks to this board :D
 

·
Super Moderator
Joined
·
26,090 Posts
Yo
Okay. I checked my pcm. I had a couple burnt spots. I replaced the resistors but I'm still having the same trouble. You think the whole board is bad?
Yo J,
If the PCM smells like dead fish, it's bad.
Other PCM killer perps are;
broken tracks,
cold solder joints,
connector pin damage or corrosion,
short circuit,
thermal stress due to excessive heat and excessive vibration that causes sensitive parts to fail,
Bronco was jump started on reverse polarity,
Overheated PC,.
Bad Intel 8061 chip or bad Intel 8361 memory chip,
Bad Internal Voltage Regulator, see Wayback Machine by Ryan M

Member jermil01 wrote, "I've used G7 in the past..good company and responsive. If your EEC has a faulty capacitor or resistor as is the case with most of them it's usually fixable as long as the board isn't damaged, but they need to have to be able to determine that. A while back I had a spare EEC I was going to send to them to have checked out, before I did, I snapped a pic of the board it had scorch mark. They said not to bother that the board was probably shot.."

Same day turn around is the issue. How is Plunk's @ Auto Repairs | Engine Computer Diagnostic | West Monroe, LA ?
 

·
Registered
Joined
·
13 Posts
awesome. I'll check them out! Thanks for the help!


Yo

Yo J,
If the PCM smells like dead fish, it's bad.
Other PCM killer perps are;
broken tracks,
cold solder joints,
connector pin damage or corrosion,
short circuit,
thermal stress due to excessive heat and excessive vibration that causes sensitive parts to fail,
Bronco was jump started on reverse polarity,
Overheated PC,.
Bad Intel 8061 chip or bad Intel 8361 memory chip,
Bad Internal Voltage Regulator, see Wayback Machine by Ryan M

Member jermil01 wrote, "I've used G7 in the past..good company and responsive. If your EEC has a faulty capacitor or resistor as is the case with most of them it's usually fixable as long as the board isn't damaged, but they need to have to be able to determine that. A while back I had a spare EEC I was going to send to them to have checked out, before I did, I snapped a pic of the board it had scorch mark. They said not to bother that the board was probably shot.."

Same day turn around is the issue. How is Plunk's @ Auto Repairs | Engine Computer Diagnostic | West Monroe, LA ?
 

·
Registered
Joined
·
13 Posts
Thanks so much. I have tried all of that. I am going to look into a new EEC. Thanks guys, I'll keep you posted


I wont pretend to be a pro at circuit boards or electronics board repairs at all here.
What I can tell you, is that if you have done everything in this thread ie:
Checked the harness to shift pack for rott and falling apart.
Fixed the harness if its fried.
Pin to pin check for continuity and short to ground end to end on the harness and then harness plug in to PCM plug in.
Voltage test on the shift solenoid pack pins.
Then there is NOTHING else it can possibly be.
If your trans goes into reverse and 1st gear and rolls then your pump and torque convertor are working ie your trans is not the issue.

When I did this process I opened up my pcm which I knew was now the culprit. It looked fine. As in brand new 100% fine.

Swapped it for a warranty refurbed one. Bam! Fixed. Been rolling like a champ since.

Also if you really really need to drive the truck still until you get a new PCM, cut the purple wire with yellow pin stripe in the wiring harness just after the pcm to square plug in on fender under the hood. You'll be able to drive in D no problem.
It will completely disable the power to the Torque Convertor Clutch solenoid. Basically your torque convertor will be free spinning constantly without being slowed down by the pulsing TCC solenoid (actuated by the PCM circuit the purple yellow wire goes to).

People say it will overheat and cook your trans. It probably does increase the temp of the fluid above optimal temp. For sure. I drove my truck with the wire cut for over a month waiting for my new PCM to arrive. Its fine. Swapped the pcm, connected the wire and bam, she was good to go. Been driving it for 8 months and good to go!

Dont start poking around in the box too much brother, you'll drive yourself crazy. Find a shop that refurbs them, see if you can buy a new one refurbed and give them your old one for a core return.

Did you run all the diagnostics above?
It can only be the PCM if you did. Legit.
 
1 - 20 of 20 Posts
Top