Diagnostic Aids

This test is used to diagnose the following:

• Clean Tachometer Output (CTO) harness circuit.
• Faulty PCM.
• Faulty Transmission Control Module (TCM).

Clean Tachometer Output (CTO) circuit from PCM is monitored by TCM. DTC P0725 indicates TCM did not receive a proper voltage signal from PCM. Possible causes are as follows:

• CTO circuit is open, or shorted to GND or VPWR.
• Camshaft Position (CMP) sensor circuit is open, or shorted to GND or VPWR.

For DTC P0725, RPM PID should increase as accelerator pedal is slowly depressed while engine is running.

Fig 1: Identifying Clean Tachometer Output Circuits

Courtesy of FORD MOTOR CO.