P0726-ENGINE SPEED INPUT CIRCUIT RANGE/PERFORMANCE

For a complete wiring diagram Refer to Section 8W.

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.



Possible Causes
ENGINE DTCS PRESENT
POWERTRAIN CONTROL MODULE

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 42RLE - STANDARD PROCEDURE)



Diagnostic Test

1. CHECK IF THE DTC IS CURRENT

Start the engine.

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


With the scan tool, read DTCs.

Is the status Active for this DTC or is the STARTS SINCE SET counter set at 0?

Yes


No

2. CHECK IF ENGINE DTCS ARE PRESENT

With the scan tool, read engine DTCs.

Are there any engine DTCs present?

Yes


No

3. 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 DTC EVENT DATA to help identify the conditions in which the DTC was set.
Check for Service Information Tune-ups or Service Bulletins for any possible causes that may apply.

Were there any problems found?

Yes


No