I have a few dtcs. what do they mean

  • Sponsors (?)


p0136 h80 HO2S Sensor Circuit Malfunction (HO2S-12), lack of switching.
p1401 hE10 DPF EGR Sensor Circuit High Voltage Detected
p1000 n/a ready tests not complete. Likely from EGR problem.
p0860 can not find in my references.

Does this car have the cats removed? If so, P0136 is from that. Will need an MIL or custom tune.

The P1401 indicates a problem in the EGR system.

HE10 DTC P1401: VERIFY DIFFERENTIAL PRESSURE FEEDBACK EGR (D.P.F. EGR) SENSOR VOLTAGE
DPF EGR circuit open
VREF short to PWR
Damaged DPF EGR sensor
DPFEGR circuit short to PWR
SIG RTN circuit open
Damaged PCM

Since the P1401 specifically calls out the DPFE as the problem, start there. Look for wiring problems ect. If none found consider replacement.

Was a DPFE that matched the PCM used?
 
i have codes

p0136
p1401
p1000
p0860

the car stutters when i hit the gas a little to hard. i pulled the codes but cant figure out what they mean.

p0136 - O2 Sensor Circuit Low Voltage (Bank 1, Sensor 2)
p1401 - Differential pressure feedback EGR circuit high input
p1000 - Monitor testing incomplete
p0860 - Gear shift module communications circuit

Whatever fault is in the EGR system generating that code (1401) may be commanding too much EGR and causing driveability issues. The trans code (0860) definitely needs attention too. The other two -- 0136 and 1000 -- are emissions related and shouldn't affect driveability. The right rear O2 sensor or wiring may have a fault but since it's only used to test the operation of the cat and not for fuel feedback, don't expect it to cause your problem. The readiness test code will remain until all emissions faults are corrected and the PCM can perform its system checks.
 
p0860 - Gear shift module communications circuit
The PCM is not going to command any EGR when there is a failure in the EGR system. There will either be full flow or no flow. If full flow, the drivability would be terrible. IMO, more likely no flow due to failure in the DPFE sensor/circuit.

IMO, the drivability issues are more likely from the P0860 (good find). I am going to assume this is an automatic transmission. The PCM is not able to correctly control the transmission (shift/lock up ect), thus the hesitation.

Excellent catch about the rear O2 sensor DTC from one side. I agree, more likely to be a wiring fault than from mod. As the mod would affect both sides.

I suspect this is a new motor install. Possible that the wiring harness has been damaged during the install.
 
yes the cats are removed. its a manual trans. i have the egr removed. it is a new motor but it didnt have this problem until a couple months after the install which is why it doesnt make sense that out of no where it starts having some kind of electrical problem or whatever is going wrong
 
So with no EGR and no cats, the associated codes can be ignored. That leaves the transmission code P0860. Focus your efforts there. Since the original post did not contain the specific information about the sequence of events and how much time has past, my assuption was a new install. The most logical conclusion is a wiring problem.

Esp since the EGR/O2 codes would be associated with a wiring problem. Important to list all of the mods.

A thought. Have you used a PCM that originally was an automatic?

When did the problem begin?
 
Guessing? Grasping? Yes a bad ground could cause all kinds of problems. However, for a bad engine ground, one might actually expect far more problems than what has been reported.

This thread was originally opened to review some DTC's. All have been explained away by modifications made (except for the transmission one). Have you done any diagnosis work yet?

Note, I am not really certain what the effect to drivability would be with a communication problem between PCM/Trans for a manual application. I am certain the results would be bad for an automatic.

Also, since the car ran fine for so long, couldn't this be a common garden variety misfire problem?

Suggest looking at the usual stuff. Water in the spark plug holes. Fouled plugs. Old/burned ignition wires (not always apparent). Bad coil pack. Dirty MAF. Vacuum leaks. Intermittent/loose/weak/noisy TPS.

Report back when you have some results.
 
i didnt know the tps made noise? it ran fine for a few months and has been doing this for a few now. i checked the coils packs wires look ok plugs are new. it is possible for a vaccume leak it kinda sounds like it but i cant tell if its just the cai on the car. how would it run fine than all the sudden get a vac leak? i didnt even know the computer needed to run to the trans being it a manual. its not a problem in the trans anyway its a motor problem
 
The wires can still be bad even though they look OK. But since you have checked everything already mentioned, will move on.

So now the major complaint now is runs very rich (no addtional DTC). Either:

Datalog the Air flow(MAF), LTFT, STFT, TPS, RPM, Fuel-pressure, injector duty cycle at idle and some higher RPM's. Post the result.

OR.....Replace the MAF.