P0725

P0725-ENGINE SPEED SENSOR CIRCUIT

For a complete wiring diagram, refer to: Electrical Diagrams

When Monitored
Whenever the engine is running.

Set Condition
The Engine RPM is less than 390 or greater than 8000 for more than 2 seconds while the engine is running.

Possible Causes
- ENGINE DTCS PRESENT
- POWERTRAIN CONTROL MODULE

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

Theory of Operation
The PCM uses a dual port RAM internal to the controller to send the engine speed signal to the Transmission Control System. The calculated engine RPM is compared to a minimum and maximum value. If the PCM interprets this signal to be out of range when the engine is running the code is set. The MIL illuminates after 10 seconds of vehicle operation and the transmission system defaults to Limp-in mode.

Diagnostic Test
1. CONDITION FOR DTC P0725 IS PRESENT Start the engine.

NOTE: This DTC is not a Transmission Input Speed Sensor DTC.

With the scan tool, view DTCs.
Is the status Active for this DTC or is the STARTS SINCE SET counter set at 0?
Yes >> Go To 2
No >> Go To 4
2. ENGINE DTCS PRESENT
With the scan tool, read Engine DTCs.

Are there any Engine DTC's present?
Yes >> Refer to - Engine Electrical Diagnostics and perform the appropriate diagnostic procedure.
Perform 42RLE TRANSMISSION VERIFICATION TEST - Ver 1. Verification Tests.
No >> Go To 3
3. POWERTRAIN CONTROL MODULE
Using the schematics as a guide, inspect the wiring and connectors. Repair as necessary Pay particular attention to all power and ground circuits.
If there are no possible causes remaining, view repair.

Repair
Replace the Powertrain Control Module per the Service Information. With the scan tool perform QUICK LEARN, then program the Pinion Factor in the Front Control Module.
Perform 42RLE TRANSMISSION VERIFICATION TEST - Ver 1. Verification Tests.
4. INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set the DTC are not present at this time.
Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.
Wiggle the wiring and connectors while checking for shorted and open circuits.
With the scan tool, check the EATX DTC EVENT DATA to help identify the conditions in which the DTC was set.

Were there any problems found?
Yes >> Repair as necessary.
Perform 42RLE TRANSMISSION VERIFICATION TEST - Ver 1. Verification Tests.
No >> Test Complete.