Bronco Forum - Full Size Ford Bronco Forum banner
1 - 4 of 4 Posts

·
Registered
1991 Ford Bronco XLT 302/E4OD
Joined
·
33 Posts
Discussion Starter · #1 ·
So I pulled my codes this morning, I did both engine off and engine running. The codes I have are 172, 173, 213, 327, 328, 332, and 334. I know what most of them mean I'm just trying to figure out where to start troubleshooting. The truck runs fine, idles a little high at times but doesn't miss or run rough. It has been running rich. Known issues I have right now is my PCV is bad, I've got a new one already just have to find time to do it. Could probably replace all my vacuum lines while I'm at it. Lastly my air injection tube at the cat is rusted off so it's not currently attached, will be replacing it soon.
 

·
Super Moderator
Joined
·
29,768 Posts
Yo tops,
At times, multiple codes may be caused by leaking capacitors or defective resistors, etc in an EEC.
But may as well check the codes before inspecting EEC.
DTC172
HEGO (H2OS) sensor circuit indicates system lean
Inspect harness...
H2OS Failure, in POSSIBLE LOCATIONS OF WIRING SHORTS TSB 95-02-11 for 92-95 Bronco & F Series; "the HO2S wires in the 12A690 (subassembly of the 14B060 battery cable) harness may be cut on the lower right engine mount causing improper signals to be sent to the PCM. Damage may be under the electrical tape..."
HO2S Failure Or Fuse "E" Inoperative, ABS Light On, Back-Up Lamps Inoperative, Daytime Running Lamp (DRL) Inoperative, MIL On, Inadvertent Self-Test, Speedometer Inoperative & Trailer Battery Charge Relay Inoperative in TSB 95-5-21 for 92-95 Bronco & F Series;
View attachment 186035
"...the HO2S wires in the 12A690 (subassembly of the 14B060 battery cable) harness may become chafed and the vehicle could exhibit any one of the following conditions;
Lack of proper HEGO operation may cause, or be the result of a rich or lean fuel condition, which could cause additional heat in the catalyst. Perform self test KOEO and KOER, service any codes. CHECK FOR PROPER HEGO GROUND. If the HEGO ground is good, the following areas may be at fault: ..." READ MORE
Source: by Ford via BANNED MEMBER Steve83 (Steve, That dirty old truck) 1983 Ford Bronco TSBs & FSAs (Recalls) for '83-96 Broncos & F150s picture | SuperMotors.net

If MAF SENSOR SYSTEM IS INSTALLED;
DTC 172 lean Heated O2; "...Backprobe the MAF (+) and MAF-RTN (-) lines with a DVOM. You shoul see ~1.0V or slightly less at warm idle. If not, check the +12V and GND lines to make sure there's battery voltage between those terminals with the ignition key turned ON. You also may want to try using the proper spray cleaner on the MAF wires, especially if you have a K&N; oily filter (in which case I can almost guarantee there's oily junk on your MAF's wires). Also make certain that the tube(s) leading from the MAF to the throttle body are 100% intact. The red wire (on the right in the first above picture) is supposed to have battery voltage with the key on. Measure between that wire and the one right next to it. You measure the MAF voltage at idle, because the MAF voltage is what's interpreted by the PCM..."
Source: by SigEpBlue (Steve) at FSB


DTC 173
173, see diagnostics by Ford @ https://www.thedieselstop.com/faq/9497faq/maint/vra/vra06050.htm#ppth1

DTC 172, 173 or 41 for HO2S Failure, in POSSIBLE LOCATIONS OF WIRING SHORTS TSB 95-02-11 for 92-95 Bronco & F Series; "the HO2S wires in the 12A690 (subassembly of the 14B060 battery cable) harness may be cut on the lower right engine mount causing improper signals to be sent to the PCM. Damage may be under the electrical tape..."



Item Part Number Description
1 11450 Starter Motor Relay Assembly
2 N803991-S36 Screw
3 14A396 Cap
4 381561-S36 Nut and Washer Assembly
5 14B060 Cable Assembly
6 Starter Solenoid Heat Shield 5.0L/5.8L Only (Part of 11002)
7 382747-S36 Screw and Washer Assembly
8 N805403-S100 Nut and Washer Assembly
9 11N087 Cover — Starter Solenoid (Red)
10 56558-S Bolt
11 34943-S36 Star Washer
12 14301 To Engine Ground
13 12A690 Wire Assembly
14 11002 Starter Motor
15 To Heated Oxygen Sensor for 5.0L/5.8L Under 8500, 5.8L over 8500 and 7.5L F-450
16 N621906-S36 Nut
17 N806925-S36MG Stud
18 12A581 Body Grounds
19 14301 Chassis Ground
20 — For Continuation Refer to Fender Apron, Right, Gasoline Engines Illustration
21 To Heated Oxygen Sensor for 5.0L/5.8L Under 8500, 7.5L F-450
22 12A690 Wiring Assembly For 5.8L Bronco
23 N802777-S36 Bolt for 14301 Frame Ground
24 9S286 Existing Gas Vapor Tube
25 10655 Battery
26 33799-S2 Nut (Auto Transmission)
27 5A212 Exhaust Pipe
A — Tighten to 7-9 Nm (62-80 Lb-In)
B — Tighten to 21-29 Nm (15-21 Lb-Ft)
C — Tighten to 10-14 Nm (7-10 Lb-Ft)
D — Tighten to 25.5-34.5 Nm (19-25 Lb-Ft)
E — Tighten to 9-12 Nm (80-106 Lb-In)
F — Tighten to 11-16 Nm (8-12 Lb-Ft)


DTC 213 (R) Ignition SPOUT or SAW circuit open or shorted Pin-Point Test; Before proceeding with this Pinpoint Test, verify that the base timing check has been performed. Key off. Disconnect Powertrain Control Module (PCM). Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary. PCM disconnected.[/B] (be careful, I hate to touch that connector!) Key on, engine off. Measure voltage between Test Pin 37 and Test Pin 40. Measure voltage between Test Pin 57 and Test Pin 60. Is each voltage greater than 10.5 volts? If not, see DTC 211 in TSB 95-15-11 for possible open/short location

View attachment 183671
EEC IV 60 Pin Connector Pin Diagram by absent member Fireguy50 (Ryan M)

DTC 332
A vac leak could cause DTC 332 - Insufficient EGR flow detected
Listen for a hiss; check hose from EVP back to EVR
See my Vacuum leak test in post #11 incl some jowens126 HVAC Control Panel pics/info @ Help with dtc codes and idle
Excerpts: One way to do a quick check is to grab a vacuum gauge. Some parts stores will loan you a gauge with refundable deposit.
The vacuum gauge should read between 15 and 22 in-Hg depending upon the engine condition and the altitude at which the test is performed. SUBTRACT ONE INCH FROM THE SPECIFIED READING FOR EVERY 1,000 FEET OF ELEVATION ABOVE SEA LEVEL.
The reading should be quite steady. .
When engine is rapidly accelerated (dotted needle), needle will drop to a low (not to zero) reading. When throttle is suddenly released, the needle will snap back up to a higher than normal figure.

When vacuum leaks are indicated, search out and correct the condition. Excess air leaking into the system will upset the fuel mixture and cause conditions such as rough idle, missing on acceleration, or burned valves. If the leak exists in an accessory unit, such as the power brake, the unit will not function correctly. Or Air Conditioning when in MAX mode may switch to Defrost.

Possible Causes; "...EGR valve sticking closed
EGR valve diaphragm leaks
EVR solenoid sticking closed
Loss of vacuum to or from EVR
Open in EVR VPWR or driver circuits
Continuous Memory DTC 332 indicates the EGR valve did not open with the engine stabilized and the EVR solenoid duty cycle present sometime during vehicle operation.
Possible causes: "...Obstructed or cracked hose to EGR valve,Icing, Damaged EGR valve, Damaged EVR solenoid harness..."
Source: by Ford via SigEpBlue (Steve)
DTC 332 "...Insufficient EGR flow detected. Atop the EGR valve there is a sensor called the EVP (EGR Valve Position) sensor. It detects movement of the pintle iside the EGR valve. You can apply vacuum to the vacuum barb on the EGR valve and observe through the holes in the casting whether the valve is moving or not. It may just be dirty which requires some careful scrubbing and NO SOLVENTS. Otherwise, if the EGR valve is functioning and moving when vacuum is applied, the EVP sensor is suspect and the electrical connections to it should be checked first. (Computer needs to know the EGR valve position for emissions control)..."
Source: by greystreak92 (Joe B)

DTC 332 & Possible Causes; "...EGR valve sticking closed EGR valve diaphragm leaks EVR solenoid sticking closed Loss of vacuum to or from EVR Open in EVR VPWR or driver circuits ..."
Source: by latechsho at Super High Output
Testing; "...There shouldn't be any vacuum at the EGR valve at idle or any time your ass is under the hood fiddling with it, to put it plainly, except for perhaps a very light residual vacuum from the EVR. Check ALL of your vacuum lines FIRST, and the vacuum reservoir for leaks..."
Source: by SigEpBlue
EVR TESTING; "....check the filter on the solenoid. If this is clogged it will inhibit the venting of the solenoid; "...EVR Solenoids should be 20 to 70 ohms (100 to 135 ohms for 7.5L engines). A functional test can be performed on most applications by using a Scan Tool. Enter the Output State check and cycle the accelerator pedal. This will turn all the solenoids on and off. Using a DVOM monitor the voltage at the EGR solenoid(s). They should toggle from a high voltage to a low voltage. Typically this is stated in the manuals and scan tools as above 10.5 volts to below 2 volts. If the voltage does not toggle make sure that you have system voltage on the power side of the connector. If system voltage is present and the voltage does not cycle to the low side check the connector and wiring to the PCM. If the wiring and connector are okay the problem may be in the pin at the PCM or the driver in the computer itself..." by Tomco.
======
EVP Testing & Replacement @
EGR Valve Position (EVP) Sensor Testing & Replacement by Seattle FSB

DTC 328, 327 or 337 Troubleshooting; Continuous Memory DTC 328 or 327 indicates the EGR valve was closed further than normal or EVP sensor or circuit has failed with an intermittent low voltage sometime during vehicle operation. Continuous Memory DTC 337 indicates the EVP signal to the Powertrain Control Module (PCM) was above the maximum Self-Test limit sometime during vehicle operation. Possible causes: Poor continuity in EVP harness or connectors. Intermittent open or short in EVP sensor or harness. Damaged EVP sensor..." READ MORE
Source: by SigEpBlue (Steve) at FSB


DTC 334 EGR (EVP) closed valve voltage higher than expected; "...Failed sensor, & as by rla2005 (Randy) wrote; carbon between EGR pintle valve and seat holding the valve off its seat. Remove the EGR valve and clean it with carbon remover. Prior to re-installing see if you can blow air through the flange side of the EGR by mouth. the egr is not closing properly which can cause detonation. remove the egr and clean off any carbon built up on it with carb cleaner and a brush if necessary..." read more
Source: by rla2005 (Randy) & miesk5 at FSB
 

·
Registered
1991 Ford Bronco XLT 302/E4OD
Joined
·
33 Posts
Discussion Starter · #3 ·
@miesk5 Thank you so much! I'll start working through troubleshooting all that on a warmer day or when I can get in the garage. Currently a cool -11 degrees Fahrenheit with wind chill where I'm at. Out of curiosity if it is bad caps and such on the EEC are those something that I could fix myself? I've got a bit of experience with soldering but I wouldn't call myself a pro by any measure.
 

·
Super Moderator
Joined
·
29,768 Posts
@miesk5 Thank you so much! I'll start working through troubleshooting all that on a warmer day or when I can get in the garage. Currently a cool -11 degrees Fahrenheit with wind chill where I'm at. Out of curiosity if it is bad caps and such on the EEC are those something that I could fix myself? I've got a bit of experience with soldering but I wouldn't call myself a pro by any measure.
Yo TOPS,
Other member have replaced at least the caps and resistors.
Consider this 87-96 Capacitor Repair Kit @ Amazon.com: 1987-1996 Ford ECU Capacitor Repair Kit : Automotive
Or;


VERY GOOD FEED BACK! $10.10/ea. FREE Standard Shipping | See details USA INCLUDED

$12.99 INSTRUCTIONS INCLUDED!

Some REPAIR articles;
Capacitor Repair in a 90 5.8
Source: by seedpress (dolittle)




Good fortune friend!
 
1 - 4 of 4 Posts
Top