Diesel Data: Automotive Repair

P0726

DTC P0726: Range/Performance Problem in Engine RPM Signal Input Circuit
2005 Model

NOTE:
^ Record all freeze data and review General Troubleshooting Information before you troubleshoot.
^ This code is caused by an electrical circuit problem and cannot be caused by a mechanical problem in the transmission.

1. Raise the front of the vehicle, make sure it is securely supported, and allow the front wheels to rotate freely.
2. Start the engine, and shift into the D position. Push on the accelerator pedal until the rotational speed of the DRIVE PULLEY is the same speed as indicated by the freeze data.
3. Monitor the ENGINE SPEED and DRIVE PULLEY with the HDS in the data list.
Do the ENGINE SPEED and DRIVE PULLEY signals fluctuate with the same speed?
YES- Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the gauge assembly and TCM.
NO- Go to step 4.
4. Check the tachometer in the gauge assembly operation.
Does the tachometer operate properly?
YES- Go to step 5.
NO- Replace the gauge assembly.
5. Turn the ignition switch OFF.
6. Disconnect TCM connector A (26P).
7. Disconnect ECM connector A (32P).





8. Check for continuity between TCM connector terminal A5 and ECM connector A19.
Is there continuity?
YES- Check for loose or poor connections at TCM connector terminal A5 and ECM connector terminal A19. If the connections are OK, substitute a known-good TCM, then recheck. If the symptom/indication goes away with a known-good TCM, replace the original TCM.
NO- Repair open in the wire between TCM connector terminal A5 and ECM connector terminal A19.