Codes and questions

[bn6339]

Hi all,

Newbie here, have a 1994 Splash (4.0, auto) and I have some questions. The dreaded CEL illuminated the other day, and I checked some codes:

KOEO

Code 111 System OK
Code 176 Oxygen sensor bank 2 (LH side) Lean
Code 542 Fuel pump circuit open

KOER

Code 116 Coolant temp out of range (I didnt do the engine running at full operating temp, as codereader connectivity slowed me down for a bit)

Code 538 Insufficient RPM change during self test (I never touched the throttle)

Code 536 Brake not pressed during KOER test (I didnt hit the brake either)

This was my first KOER test, so maybe I didnt do everything I was supposed to...but its the engine off codes Im concerned about....now, I checked *only* the oxygen sensor circuit, as I believe (right now) that the code 176 and 542 are related....which scares me a little, because what the Powertrain Diagnostic manual said regarding this circuit....if I have no voltage in the LH oxy sensor harness (H02 signal wire), then the PCM is toast....ideas?
I am planning to change the battery (battery was from 2004, and I have a replacement handy) and the cables, as Im wondering if that might also create issues.... Further questions? I searched a bit, but really didnt find anything specific to my issue...thanks for your help!

 

[bn6339]

UPDATE: Sorry, its been awhile, needed to check some things before I posted again...I still have some fuel trim issues (ie left bank (or both banks)lean, can hear it ping like a diesel) BUT Im not setting codes when I drove the truck various speeds from town to freeway, back to town. I replaced the battery cables with some custom 4awg aftermarkets (100ish/pair) which eliminated the sporadically changing codes each time I connected the box to the truck.....Planning to replace the fuel and air filters, since they're cheap and it probably needs them anyway.....stay tuned for further updates

 

[Sasquatch_Ryda]

If you are having lean bank issues check for vacuum leaks by spraying carb/brake cleaner around vacuum lines and the throttle body/intake/lower intake. If you idle picks up you've got a vacuum leak.

 

[bn6339]

More codes, and of course questions

Hello again....I replaced a few items, and solved a couple problems, but I still have some code issues , which is confusing me..... I accomplished the following this past summer--

1. Replaced intake manifold gaskets (upper and lower)
2. Fuel injectors professionally cleaned/calibration verified
3. Fuel regulator checked w/injectors
4. Cooling system flushed/thermo replaced
5. New serp belt
6. Fuel filler replaced (old one seriously cracked)
7. Checked for obvious vac leaks

When I drove the truck to the emissions station (she passed, btw, YES ) it was fine (no CEL) until I gave it some throttle up hill and it set the light, which stayed on for about 3-5 mins, then extinguished. Arrived @ home, I read codes and saw the following:
(KOEO only)

565 (O) Canister Purge 1 solenoid/circuit failure - Solenoids
176 (M) Oxygen sensor not switching - system is or was lean Left or Front HO2S - Fuel control

I tested the CANP solenoid, it ohmed within Ford spec, and Im also seeing the appropriate voltage (above 10.5v) on the VPWR lead, so I will eventually need to use my breakout box and see if theres a wiring issue, or **coughs** the PCM decided death was necessary.....

I realize I need to run the KOER test, just decided my day was already frustrating enough to start again tomorrow, and since Im off from tomorrow night until Dec 28, I will drive the truck a bit again and see what happens with a complete test regimen.

Things I need to do (which may or may not help this specific issue, but wont hurt, since they are cheap)

1. Replace fuel filter
2. Replace vapor canister elbow from solenoid to canister top (almost rotted)
3. Test fuel pressure with a gauge bought last summer
4. Recheck for vacuum leaks (ie rotted hoses)
6. Replace fuel pump oring (I still smell fuel, and narrowed it down to this area, as I see no obvious leaks/cracks, which of course could change when I remove the bed)
7. check wiring with breakout box per the service manual diagnostics (ruling out shorts/harness issues)

Im **sorta leaning** to a bad PCM, HOWEVER I want to test/verify these items before I start throwing serious money that direction....if anyone has any suggestions/ideas, Im very open....thanks!!

 

[ashleyroachclip]

The PCM is not that scary of a thing to check , and even repair burnt trace, and change a component.

, to determine a problem with a component Once removed from the vehicle , and the removal of 4 screws, you only have to smell it to determine a problem.
The PCM has 2 sides you can access for a total of 8 screws (torques bit).

I have found problems in the o2 sensor harness that causes problems ,including shorting the trace.
With burnt trace all you need to do is solder a piece of wire to re-complete the circuit.
Capacitors need to be replaced with the same...Radio Shack , and DiGi have everything you need to make an electrical something .

 

[bn6339]

The PCM is not that scary of a thing to check , and even repair burnt trace, and change a component.

, to determine a problem with a component Once removed from the vehicle , and the removal of 4 screws, you only have to smell it to determine a problem.
The PCM has 2 sides you can access for a total of 8 screws (torques bit).

I have found problems in the o2 sensor harness that causes problems ,including shorting the trace.
With burnt trace all you need to do is solder a piece of wire to re-complete the circuit.
Capacitors need to be replaced with the same...Radio Shack , and DiGi have everything you need to make an electrical something .

What specific problems with the o2 harness? Chafed/burnt wires/bad connection/shorting to ground (ie exhaust pipe)? I appreciate your input, I can focus on that circuit to see what I can repair.....thank you for your idea!!

 

[bn6339]

Continuing...

I read the codes you address first are "hard faults" which in my case was 565 (Canister Purge Circuit/Solenoid failure.) I therefore need to replace my canister solenoid (failed the Ohm test), and of course I trashed the vacuum line from the canister-solenoid-throttle body....does anyone have a part number, or did you just use some steel line with rubber hose endings? Refreshing info, '94 4.0 auto...and we are getting closer.....yes!!

 

[bn6339]

More...

Hello again,

Still haven't checked electrical, since outside temps plunged this last week, and freezing is something I do while working, so when I'm home, I stay upstairs and warm (lame/wimpy I know ) I did however, repair the vapor canister line with 1/4" steel brake line, appropriate fittings I could finesse to the engine, and a new solenoid. Reset the computer, and Im gonna drive it again and see what transpires....