1999 help please

inline6power

inline6power

more hp than you
Joined
Apr 15, 2007
Messages
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Well the last couple of weeks truck has been throwing a 0122 apps Los circuit a. I am now on my third new sensor. Same thing, code is still coming up and once every 3 times I drive the truck it sorta bucks at very light throttle. Like I am letting off the pedal and then getting back on it. Only does it at very light throttle. This is driving me crazy. Also feels like very very low power in overdrive. What else could cause a 0122 code besides the actual apps sensor? Thanks in advance

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could be bad ecm, pcm, bad connector or wiring. You need to check the votage at the ecm and then at the connector to see were your loosing it at
 
DISTURBED said:
could be bad ecm, pcm, bad connector or wiring. You need to check the votage at the ecm and then at the connector to see were your loosing it at
Click to expand...

I checked voltage at the pcm and it seems fine but it only bucks every other time driving it and I can't ever seem to make it do it while truck is off with key on voltage. Driving me crazy. Also when smarty is in the truck has power right off the line then nothing. If I plug my old van aaken box in which goes directly to the vp has way more power. But bucking gets worse. How would I check for a bad ecm

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Thats what shopkey said. I would back prob the ecm and see what the voltage is coming from there. then check resistance on the wire from the ecm to the apps and also check it from the pcm. And you did relearn the sensor and clear the codes on both side of the computer right.
 
DISTURBED said:
Thats what shopkey said. I would back prob the ecm and see what the voltage is coming from there. then check resistance on the wire from the ecm to the apps and also check it from the pcm. And you did relearn the sensor and clear the codes on both side of the computer right.
Click to expand...

Yup relearned all three times with all three new sensors. The newest one in the truck is the Timbo apps. All do the same thing I described. It's weird when it starts to buck because if I give it just a tad more throttle say 1/4 throttle instead of 1/8 it completely goes away but power still feels like it's down. Just seems like the computer is telling it to cut fuel in and out and feels like it won't let it get full fuel in overdrive.

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If you new someone with the same truck swap the ecm and see if it goes away
 
DISTURBED said:
If you new someone with the same truck swap the ecm and see if it goes away
Click to expand...

Going to see if I can find a 99 manual ecm to try. Is it possible a bad map sensor can cause this? I am more leaning towards a ecm than anything. Vp only has 15k on it

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did you go over all the grounds? also check the black/ltblue (iirc) wire for ground. Sounds like you almost have a crappy ground or a pin backed out of a connector.
 
tractorguyacb said:
did you go over all the grounds? also check the black/ltblue (iirc) wire for ground. Sounds like you almost have a crappy ground or a pin backed out of a connector.
Click to expand...

Found it. It was actually the dark blue with white tracer that goes from pin 5 on apps to pin 31 on ecm. All is fixed now

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inline6power said:
Well the last couple of weeks truck has been throwing a 0122 apps Los circuit a. I am now on my third new sensor. Same thing, code is still coming up and once every 3 times I drive the truck it sorta bucks at very light throttle. Like I am letting off the pedal and then getting back on it. Only does it at very light throttle. This is driving me crazy. Also feels like very very low power in overdrive. What else could cause a 0122 code besides the actual apps sensor? Thanks in advance

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Click to expand...

Here is a diagnostic article to help you test out the APPS circuit...

DTC P0122: APP SENSOR SIGNAL VOLTAGE TOO LOW

Monitor & Set Conditions

Accelerator Pedal Position Sensor (APPS) voltage is monitored when engine is running. DTC may be stored if low voltage is detected on APPS signal circuit or low voltage is detected between Engine Control Module (ECM) and Powertrain Control Module (PCM).

Possible Causes
■ 5-volt Supply At APPS Shorted To ECM Sensor Ground
■ APPS Signal Circuit Shorted To ECM Sensor Ground
■ 5-volt Supply To Ground
■ APPS Signal Circuit Shorted To Ground
■ APPS Signal Circuit Open To ECM
■ PCM (APPS) Short To ECM Sensor Ground
■ ECM (APPS) To PCM (APPS) Circuit Shorted
■ ECM (APPS) To PCM (APPS) Circuit Open
■ Short To ECM Sensor Ground
■ Accelerator Pedal Position Sensor (APPS)
■ Engine Control Module
■ Powertrain Control Module

Testing

1. Turn ignition on with engine off. Using DRBIII(R) scan tool, check for ECM and PCM DTCs. Determine if DTC is set by ECM or PCM. If DTC is set by ECM, go to next step. If DTC is not set by ECM, go to step 7 .

2. Turn ignition off. Disconnect APPS sensor harness connector. APPS is located on bracket, just above fuel injection pump. Turn ignition on with engine off. Using DVOM, measure voltage between cylinder block (ground) and terminal No. 5 (Dark Blue/White wire) on APPS harness connector. If voltage is greater than 4.5 volts, go to next step. If voltage is 4.5 volts or less, go to step 6 .

3. Turn ignition off. Ensure APPS harness connector is still disconnected. Check for continuity between terminal No. 4 (Black/Yellow wire) and terminal No. 5 (Dark Blue/White wire) on APPS harness connector. If continuity does not exist, go to next step. If continuity exists, repair short between Dark Blue/White and Black/Yellow wires. The Black/Yellow wire is the sensor ground circuit.

4. Ensure APPS harness connector is still disconnected. Disconnect ECM harness connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. Check for continuity between terminal No. 4 (Black/Yellow wire) and terminal No. 3 (Light Blue/Black wire) on APPS harness connector. If continuity does not exist, go to next step. If continuity exists, repair short between Black/Yellow and Light Blue/Black wires.

5. Ensure APPS and ECM connectors are still disconnected. Check for continuity between ground and terminal No. 5 (Dark Blue/White wire) on APPS harness connector. If continuity does not exist, go to next step. If continuity exists, repair short to ground in Dark Blue/White wire.

6. Turn ignition off. Ensure APPS connector is still disconnected. Disconnect ECM harness connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. Check Dark Blue/White wire for continuity between terminal No. 5 on APPS harness connector and terminal No. 31 on ECM harness connector. If continuity does not exist, repair open in Dark Blue/White wire. If continuity exists, replace and program the ECM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article.

7. Turn ignition off. Disconnect PCM harness connectors. PCM is located at passenger's side rear corner of engine compartment. Check for continuity between ground and terminal A23 (Orange/Dark Blue wire) on PCM harness connector (APPS circuit). If continuity does not exist, go to step 9 . If continuity exists, go to next step.

8. Disconnect ECM harness connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. Check for continuity between ground and terminal A23 (Orange/Dark Blue wire) on PCM harness connector (APPS circuit). If continuity does not exist, test is complete. If continuity exists, repair short to ground in Orange/Dark Blue wire. 9. Ensure PCM harness connectors are still disconnected. Disconnect ECM connector. ECM is located on driver's side of engine, just in front of fuel transfer pump and contains a 50-pin connector. Check for circuit). If continuity does not exist, go to next step. If continuity exists, repair short to ground in Orange/Dark Blue wire.

10. Check Orange/Dark Blue wire for continuity between terminal No. 5 on APPS harness connector and terminal No. 31 on ECM harness connector. If continuity does not exist, repair open in Orange/Dark Blue wire. If continuity exists, go to next step.

11. Reconnect ECM harness connector. Ensure PCM harness connectors are still disconnected. Turn ignition on with engine off. Using DVOM, measure voltage between ground and terminal A23 (Orange/Dark Blue wire) on PCM harness connector (APPS circuit). If voltage is greater than 0.4 volt, test is complete. If voltage is 0.4 volt or less, go to next step.

12. Turn ignition off. Disconnect APPS harness connector. Check for continuity between ground and terminal A23 (Orange/Dark Blue wire) on PCM harness connector (APPS circuit). If continuity does not exist, replace APPS. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. If continuity exists, replace and program the ECM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article.

Mopar1973Man's Dodge Cummins Articles - P0122 APPS Sensor Signal Voltage Too Low
 
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