P0123/P0351/P0138

vincentw56 · **Joined:** Mon Oct 17, 2005 1:54 pm **Posts:** 2

I have been having some problems with my truck lately. The problems I have had are rough idle to the point it dies and hesitation when taking off from a start. The toque converter will not lock up also. The truck has 150,000+ miles on it. I have done the normal service on the transmission every 50,000 miles.

I took it to AutoZone and got the codes from the PCM. Here are the codes and what the service manual says:

P0123 - Throttle Position Sensor Voltage High - Throttle position sensor input above the maximum acceptable voltage.
P0351 - Ignition Coil #1 Primary Circuit - Peak primary circuit current not achieved with maximum dwell time.
P0138 - Left Bank Downstream or Downstream and Pre-Catalyst O2S Shorted to Voltage - Oxygen sensor input voltage maintained above the normal operating range.

I replaced the TPS and cleared the codes. The P0123 came back.

I replaced the Upstream (before the cat) O2 Sensor and still get this code. I think this code my be due to the fact that I have removed the cat.

The P0351 code I am not sure about. I have an MSD coil and box on there. I was thinking of removing it and putting the old coil back on to see if it clears this code.

Does anyone know why the TPS is still showing bad? Is there anything else I can test? I am really at a loss right now.

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wyciwug · **Joined:** Mon Jun 18, 2007 5:56 am **Posts:** 4

Did you take care of this code? I got it on mine. New coil packs but code won't go away.

D

jeff compton · **Posted:** Mon Jun 18, 2007 6:19 am

we're at aloss because we have no idea what you're working on! :evil:

vincentw56 · **Joined:** Mon Oct 17, 2005 1:54 pm **Posts:** 2

Sorry mine was for a 1998 Dodge Dakota 318 2WD. Anyway, I the problem with the TPS was a bad wire from the PCM to the TPS. That is fixed.

The problem with CAT is because there is no CAT.

The problem with the Ignition Coil was due to the MSD box and MSD Coil. I put on the factory coil and it fixed it.

Now the none of these made the truck run bad. The reason the truck was running bad was because of a bad wire going from the cruise control into the PCM. Once that wire was removed, the truck runs as good as new. Funny how the cruise control wire can cause such problems, but I guess the computer systems are pretty sensitive sometimes.

Thanks,
Vincent

wyciwug · **Joined:** Mon Jun 18, 2007 5:56 am **Posts:** 4

My BAD, I was in a hurry and forgot. My truck is a Mazda Tribute 2001. Code was P0351. It won't go away even I replaced the coils.

Darkrooms · **Joined:** Thu Mar 29, 2007 9:44 am **Posts:** 1424

P0351 means there was no signal from the IDM. You need to inspect the ignition coil pack connection and circuits for a possible connection or circuit issue. Wiggle test the wiring of the harness between the coil pack and the PCM for a possible problem with the engine running. IF there's nothing obvious, it could be caused by a PCM problem, but you'll need to take it to a qualified shop to prperly diag. that.

wyciwug · **Joined:** Mon Jun 18, 2007 5:56 am **Posts:** 4

I am going to swap the coils around to see if that coil causes P035x, then if that's the case, the coil is bad

Darkrooms · **Joined:** Thu Mar 29, 2007 9:44 am **Posts:** 1424

Coils don't go bad very often in the box, though it's not impossible.

jeff compton · **Posted:** Mon Jun 18, 2007 10:26 am

depends on the brand I suppose!

P0123/P0351/P0138

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