Engine/Transmission (1998.5 - 2002) Dead pedal, apps

[RLord]

I have a 2001 HO with MBRP 4X4. The problem I'm having is the APPS stops working. I found a problem on this web site that has some good information. It was submitted on 05/21/14 by "mrtreecare". I'm getting the following problem codes P1693 and P0121. The other problem there was a update referring to WEB site "bluechipdiesel.com". I selected on that web site a section called "vp44diagnostichelp.html. Reading through the section Dead Pedal or intermittent loss of power. When this problem comes up on my truck goes to a idle. The pedal will do nothing. I cleaned the connection to the to both the PCM and the ECM. It was several weeks before it failed again. I think it could be the APPS but not sure. I could use some help. THANKS

 

[JLandry]

The P0121 DTC suggests a problem with the APPS, wiring harness, or ECM.

If the problem is occurring now and you know how to use a multimeter, you can follow the specific troubleshooting steps in the Dodge Diagnostic Manual to narrow down where the problem is. Let me know if you want them and I'll post the steps.

It couldn't hurt to go ahead and replace the TPS (Throttle Position Sensor) within the APPS in the hope that it'll cure the problem. If it doesn't, we'll at least you'll have a spare.

John L.

 

[RLord]

I can and have used a multimeter for work for more than 50 years.
THANKS Dick

 

[JLandry]

Symptom:

P-0121 ACCEL POS SENSOR VOLTS DO NOT AGREE W/IDLE VALID SIGNAL (DIESEL)
​

When Monitored:

During idle which is less than 15% of full throttle range for approximately 1.0 second or during not at idle and vehicle speed is greater than 10 MPH for approximately 1.0 second.
​

Set Condition:

IVS (Idle Validation Signal) indicates idle while APPS signal voltage indicates not a idle condition or IVS indicates not at idle while APPS signal voltage indicates idle condition.
​

Possible Causes:


APPS
APPS WIRE HARNESS - CIRCUIT OPEN
APPS WIRE HARNESS - SHORT TO VOLTAGE (IVS #2)
APPS WIRE HARNESS - SHORT TO VOLTAGE W/ ENGINE ON
APPS WIRE HARNESS - SHORT TO VOLTAGE WITH KEY ON
ECM​

Test 1

• Ignition off.
• Disconnect APPS Connector.
• Check connectors-Clean/repair as necessary.
• Start the Engine.
• Using a Voltmeter, measure the voltage of the APPS supply circuit. Is the voltage above 5.5 volts?
• Yes → Go To 2
• No → Go To 3

Test 2

• Ignition off.
• Disconnect APPS Connector.
• Check Connectors-Clean/repair as necessary.
• Start the Engine.
• Cycle Key Off, then On.
• Using a voltmeter, measure the voltage between the APPS supply circuit. Is the voltage above 5.5 volts?
• Yes → Repair the short to voltage, with the key on. Perform Verification Test VER-5A.
• No → Repair the short to voltage, with the engine running. Perform Verification Test VER-5A.

Test 3

• Ignition off.
• Disconnect APPS Connector.
• Check connectors-Clean/repair as necessary.
• Using an ohmmeter, measure the resistance between the APPS ground circuit and ground.
• Is the resistance above 5.0 ohms?
• Yes → Go To 4
• No → Replace the APPS.

Test 4

• Ignition off.
• Disconnect APPS Connector.
• Check connectors-Clean/repair as necessary.
• Start the Engine.
• Cycle Key Off, then On.
• Using a voltmeter, measure the voltage of the APPS IVS #2 circuit.
• Is the voltage above 4.5 volts?
• Yes → Repair the short to voltage, with the key on. Perform Verification Test VER-5A.
• Yes → Go To 4

Test 5

• Ignition off.
• Disconnect APPS Connector.
• Check Connectors-Clean/repair as necessary.
• Disconnect ECM Connector.
• Check connectors-Clean/repair as necessary.
• Using an ohmmeter, measure the resistance of the sensor ground circuit between the APPS connector and the ECM.
• Is the resistance above 5.0 ohms?
• Yes → Repair the open circuit. Perform Verification Test VER-5A.
• No→ Replace the ECM Perform Verification Test VER-5A.

Verification Test 5A

1. Check if any of the following conditions exist.
2. The ECM has been disconnected or replaced.
3. The Battery power has been disconnected.
4. The APPS has been disconnected or replaced.
5. If any of the conditions exist, perform the following steps, otherwise, go to step 8.
6. APPS Programming Procedure: Reassemble all components. Turn the ignition key to the ON or RUN position. Without starting the engine, slowly press the throttle pedal to the floor and then slowly release.
7. This step must be done (only once) to ensure the accelerator pedal position sensor calibration has been programmed in the ECM.
8. Caution: Do not attempt to adjust screws or disassemble the APPS sensor. These settings are set at the factory and are not intended to be changed.
9. If the PCM has been replaced, do the following: (Otherwise go to step 12)
10. Note: If the Powertrain Control Module has been changed and the correct VIN and milage have not been programmed, a DTC will be set in the ABS and Airbag modules.
11. For ABS and Airbag Systems: Action: Enter correct VIN and Mileage in PCM. Erase ABS and Airbag modules codes.
12. If the PCM has not been replaced, do the following:
13. All Trouble Codes should be repaired before continuing, if not, return to Symptom list and follow suggested test. After all DTC’s are repaired, return to this test and continue.
14. Connect the DRBIII to the data link connector. Ensure the fuel tank is at least 1/4 full. Turn off all accessories.
15. Note: The best way to verify an OBDII DTC repair is to allow the PCM to run the appropriate Trip and increment a Good Trip which verifies that the repair was successful.
16. Note: A component DTC will require 2 minutes of engine run time without any DTC’s to increment Good Trip.
17. Note: A monitor DTC, other than a misfire DTC, will require using the DRB pre-test screens to allow the technician to meet the requirements to run that monitor.
18. Note: A misfire DTC will require using Similar Conditions window to attempt to duplicate the operating conditions when the DTC was set to verify the repair.
19. If this verification procedure is being performed after a Component CODE repair, do the following:
20. After the ignition has been off for at least 10 seconds, restart the vehicle and run 2 minutes.
21. Did Starts since set and a Good Trip change to one or more? If yes , repair is complete, go to step 23: otherwise continue with step 22.
22. Look for any new DTC’s set during the test. If there are any new DTC’s, return to Symtom list and follow sugested path.
23. If the Good Trip counter changed to one or more, the repair was successful.
24. Erase Trouble Codes.
25. Disconnect the DRB.
26. If this verification procedure is being performed after a MONITOR TROUBLE CODE repair, do the following:
27. With the DRB III, monitor the pre-test enabling conditions until all conditions have been met to run the appropriate monitor. Run the appropriate monitor for the repaired DTC.
28. If the repaired OBDII trouble code has reset, or the OBDII monitor failed after running, the repair is not complete. Check for any technical service bulletins or flash updates and return to Symptom list.
29. If a new DTC has set, return to Symptom list and follow the path specified for that code.
30. If the monitor ran, and the Good Trip counter changed to one or more, the repair was successful.
31. Erase Trouble Codes.
32. Disconnect the DRB.
33. If this verification procedure is being performed after a MISFIRE TROUBLE CODE repair, do the following:
34. With DRB III, monitor Similar Conditions to attempt to duplicate the conditions that the vehicle was operating at when the code was set. If conditions can be duplicated, Misfire Good Trip counter will change to one or more. If not Continue with step 37.
35. If the repaired OBDII trouble code has reset, or the OBDII monitor failed after running, the repair is not complete. Check for any technical service bulletins or flash updates and return to Symptom list.
36. If a new DTC has set, return to Symptom list and follow the path specified for that code.
37. If the monitor ran, and the Good Trip counter changed to one or more, the repair was successful.
38. Erase Trouble Codes.
39. Disconnect the DRB.​

 

[cerberusiam]

You can replace the APPS and see if that helps, it is the cheaper of the two potential sources. You can test the APPS and likely it will test out OK and the problem still exist. It is a good bet there is a P0216 lurking in there somewhere, the FPCM's will go bad and throw codes back into the system that will make it seem like the APPS or PCM is bad. All you can do is test and replace what seems bad then go from there.

 

[GReed]

If you do replace the APPS, get a Timbo APPS. Genos have them or you can get them from Timbo. Do a google search for Timbo APPS. I just put one on my 2002. Very easy install, works great. There are many threads on here regarding the Timbo APPS. A lot cheaper than factory and better quality.

 

[RLord]

I should have responded before now. I don't have a garage to work in. The weather here in upstate New York has not been all that good. I believe it was on 06/05 I pulled the APPS out only to the point I could get at the plug. I cleaned both the male and female ends and put dialect grease on them. If I remember right the days that I had a failure was 80F or more. I'm retired so I don't drive as much and as fare as I once done. If I have a failure again I will go though the procedure that fellow member "jlandry" has put in this problem.
THANK Dick