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#1 Asshole
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Discussion Starter #1
I have a new problem and think I may have found the answer here
I cant get any koer codes only a solid light on my code scanner. I can pull koeo codes. They are as follows 654 mlps not indicating park during koeo self test, 553 thermactor diverter circuit failure(unhooked) and thermactor bypass circuit failure (unhooked). After the seperator I got 332 egr flow insufficient, 452 vss signal too low and finally 634 mlps signal voltage higher or lower than expected. now my question would the 654 and 634 codes cause me not to be able to run the koer self test I believe the mlps codes are due to I have been playing with it because my e4od is funky when I put it in d/od it is in neutral slap the shifter nearly to 2nd and wa-la you got drive. I have adjusted it to no avail from one end to the other and everything in between and probably forgot to set it properly when I finally got pissed off enough to say the hell with it. My battery voltage is 12.35 charging voltage is 13.84. would that be my problem and obvisoly I need to check the mlps and adjudst it if it isnt where it should be. Is there anything else I should check before chasing wires?
 

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#1 Asshole
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Discussion Starter #3
i don't think that would keep you from being able to perform the test. I think you have a bigger issue with the computer.
The reason I asked is the article said pin 30 on the ecu needs to see ground in neutral and if the mlps isn't indicating park it won't send a ground to pin 30. Really I was asking to find out if there is anything I can try if that doesnt work for me. The self test connector has a good ground I tried that one figured it would be a quick fix it was worth a try.
 

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ok, ck the wires on passenger side inner fender liner, forward of the battery; ck em all visually for corrosion... can you run a jumper from your scanner to the ground point using a thin Male spade connector? (I used to get the male spafe conn and file it down to fit inside a conn...or worse, scrape off a section of insualtion on the scanner's harness and attach an alligator clip w/jumper..
 

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can you try a self-test? wthout the Scanner?
 

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#1 Asshole
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Discussion Starter #6
ok, ck the wires on passenger side inner fender liner, forward of the battery; ck em all visually for corrosion... can you run a jumper from your scanner to the ground point using a thin Male spade connector? (I used to get the male spafe conn and file it down to fit inside a conn...or worse, scrape off a section of insualtion on the scanner's harness and attach an alligator clip w/jumper..
I already tried the ground no dice.

can you try a self-test? wthout the Scanner?
Tried sweeping test same thing. Just to let you know the scanner in which I reffer to is just the actron $20 code scanner tool. The scan tool allows me ti get koeo codes just no koer codes. I will be home in a few will adjust mlps and try yet again if no dice gonna make sure pin 30 has ground in park and neutral if not will give it one. By the way thanks for all the great info you put up here for everyone at fsb. Be back in a few with an update.
 

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ok,
I wasn't sure 'bout the ground.. meaning the grnd lead on the scanner.
Next up is this;
Test, Pin-Point in 92-96; from Ford EVTM; "...The negative lead of the multimeter should be placed at the MLPS signal-return ground terminal at the MLPS. Check the resistance of the MLPS: The resistance of the MLPS (pins 30 and 46).." read more
Source: by Ford via alldata & justanswer.com

See Figure 1

In Park (P) Pin 30 goes thru entire R set to Pin 46-Ground

In Neutral (N) Pin 30 goes thru partial R set to Pin 46-Ground

see Figure 4 for Ohms in P & N from pin 30 to Pin 46
 

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#1 Asshole
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Discussion Starter #8
miesk5 thanks for all of your help so far and for your original post I adjusted the mlps didnt change anything I coundnt do any further testing on it. I will get my multimeter in the morning and test the signals on 30 and 46 and go from there.
 

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#1 Asshole
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Discussion Starter #9
I've been playing with it off and on all day so updates I had a bad mlps no voltage or resistance to ecu replaced it everything is with in the the ranges specified by ford first gear4.47v 4170 ohms, second gear 3.67v 1445 ohms, neutral 2.89v 732 ohms, drive 2.14v 400 ohms, second 1.72v 210 ohms and first .72v 86 ohms. From pin 46 to ground I have .01 volts and yet still no koer codes whats next?
 

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yo, OK, at least that MLPS is out of the way fron now.
I believe you went thru this already?
STO/MIL circuit shorting intermittently to ground; "...Occasionally, there are reports of the Malfunction Indicator Lamp (MIL) "Check Engine" or "Service Engine Soon" lamp being lit with no Self-Test codes in Continuous Memory in MIL Explanation with No Self Test Codes TSB 92-24-3 by Ford for 91-93..."
Source: by Ford via miesk5 at cc
"...3) The Concern That Set The Continuous Memory Code Is No Longer Present
The EEC processor will erase a Continuous Memory code if the concern that caused it has not been present for 40 or 80 warm-up cycles, depending on the vehicle. A warm-up cycle occurs when the vehicle is started with the coolant temperature below 120° F (49° C) and then shutdown with the coolant temperature above 150° F (66° C). If a vehicle is brought in for service with a MIL complaint and the vehicle is driven or otherwise allowed to warm-up before Self-Test is run, the code may be cleared before the technician tests it.
4) Grounded STO/MIL Circuit
The processor controls the MIL by grounding the STO/MIL circuit (Pin 17). If this circuit shorts to ground, whether the processor is controlling it or not, the MIL will be lit. Starting in 1991, if the processor has lit the MIL, it will hold it on for a minimum of 10 seconds. If the MIL flashes quickly, the concern is probably the STO/MIL circuit shorting intermittently to ground..."
and;

Scan Tool Won’t Initiate Self-Tests; Vehicle Battery goes Dead, Short Solenoid Body Life, 4th Gear Starts in D/High Pressure may be caused by a malfunctioning Electronic Engine Control (EEC) Relay. The EEC relay is controlled by 12 volts from the ignition switch and is responsible for supplying voltage to the computer and solenoid body. If the relay contacts stick open, the complaints are as follows: Gas engine applications won’t start, Diesel will start and run, but have 4th gear starts in D, 2nd gear in 2 and 1, and maximum line pressure. If the contacts are stuck closed, the complaints may be as follows: Both gas and diesel engine application: Scan tool won’t work, vehicle battery goes dead, short solenoid body life. Note: Watch for corroded relay terminals and connectors on 89-91 E-series vans. The relay is very close to the right side battery and prone to corrosion problems especially on diesel ambulances..." read more, Diagrams are gone
Source: by ATC-Distribution Group Inc. atcdg.com via web.archive.org
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EEC, Start/Ignition, Fuel System in Electrical and Vacuum Troubleshooting Manual (EVTM) Partial, (Bronco similar for many diagrams), F 150 for 86, 89, 91 & 95; EEC, Start/Ignition, EFI/Fuel System, Emissions, E4OD, AOD/C6 (+ clutch interlock switch), etc.
Source: by Ford via Ryan M (Fireguy50) at http://fordfuelinjection.com/?p=36here are some excerpts to start TS; hopefully these color codes are correct for your 91 Bronco; I did do a few checks a week ago for someone else and the sensors I checked were same as Bronco.


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PIN 17
 

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So, let's fool around w/that EEC relay for a sec or 3...
Jermil's EC relay seemed to be da prob for him; "....As luck would have, it appears that changing out the old EEC relay did the trick. At first I didn't think it would. Instead of using wire from the self test connector to the battery, I plugged it directly into the connector on the tool and went through the KOEO code retreival process and lo and behold I got codes..I even got the KOER test to work as well..."

You can try the tap/and or wiggle on it; or swap to a Bosch style ala the 92-96 years.
Fuel Pump Relay & EEC Relay Color Codes; for troubleshooting/swapping to Bosch Style relays
Source: by Steve83 (Steve, That dirty old truck) at FSB
 

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#1 Asshole
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Discussion Starter #13
ok update checked all of the hots and grounds at the ecu all good I will be out (on this one no time for a few days ) Thank you for everything so far I will buy a chiltons as soon as I can so I can have a paper copy of the diagrams. I will try to do what I can and will update you as I can btw I will buy a new relay in the a.m. and try that.
 

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ok
But save a few bucks and check that EEC Relay, wiring, etc.
Also, I see that Jermil was able to use the multi-meter (MM, sweep) test on KOER
I have another bad Comcast cable day here so going back to see what he wrote is tuff.

Have to figure out why the MM SWEEP test worked on KOER, but the Scanner and jumper test didn't work!
 

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ok, made an error;
Scan Tool Won’t Initiate Self-Tests; Vehicle Battery goes Dead, malfunctioning Electronic Engine Control (EEC) Relay in a 92
Source: by Jeremy M (Big 92, jermil01) & miesk5 at FSB



Jermil wrote on Page 2;

"...I was able to get codes the old fashioned way by counting the flashes on dashboard, so I think that would eliminate any prospect of it being something in the wiring; ....As luck would have, it appears that changing out the old EEC relay did the trick. At first I didn't think it would. Instead of using wire from the self test connector to the battery, I plugged it directly into the connector on the tool and went through the KOEO code retreival process and lo and behold I got codes..I even got the KOER test to work as well..."
 

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#1 Asshole
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Discussion Starter #16
Ok I have rechecked everything and even hooked the emmisions crap back up and ow have only 2 codes on the koeo test 654 mlps not indicating park during self test and after the seperator 634 mlps voltage too high or too low I have done a search ( quick one gotta go to a dr. appt) but I need to know where all the wires on the mlps come from and go to to further diagnose this I think this is still the problem or just a bad ecu but why would 2 brand new mlp sensors do the same thing however the first was bad it had no resistance between pins 2 and 3.
 

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and it appears it's time to get the haynes or as Seabronc wrote here awhile ago;
"...There are currently several EVTMs for sale on ebay on a Buy It Now basis. That manual is one of the best books you can invest in for trouble shooting and maintaining your truck. You can find them with a simple search, "Ford Bronco EVTM", no quotes.

Bronco+EVTM

Ford produced hard copy versions of them for every model vehicle they have manufactured from atleast 1980 and up. After 96 the service manuals were produced on CD and DVD.

If you don't find one listed on ebay for your truck, just contact one of the sellers. They may have one that is not listed yet or you may be able get them to keep an eye out for you.

That is the source of the diagrams that I often include in my posts..."
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#1 Asshole
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Discussion Starter #19
Thanks for all the help I will look into this further and give everyone updates as they happen.
 

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yo,
ok, this is a problem that needs the EVTM/PCED diagrams to get to the ckts
 
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