P0702

NOTE: The ignition supply voltage must be greater than 8 V for a fault code to be stored. If this fault is permanently flagged, the TCM should be replaced taking care to obtain the correctly programmed variant.

TRANSMISSION CONTROL SYSTEM ELECTRICAL - P0702
This fault code is associated with the internal relay of the Transmission Control Module, (TCM). This relay provides a means of isolating the electro-mechanical, controlling, solenoids from the supply, allowing the transmission to revert to a mechanical default condition.

The relay and associated circuitry is tested once during initialization and whenever a hardware reset occurs. When the ignition is first switched on the TCM carries out an initialization routine. During this routine the processor drives the relay ON then tests for the supply voltage on the output via a feedback path. If the supply voltage is not seen within a specific time then a fault is flagged and the TCM will run in default mode and this fault code will be stored.

A set time after the relay is turned ON, it is turned OFF and the processor then tests for the supply again. If it is still present, then the TCM will run in default mode and this fault code will be stored.

Possible Causes: Faulty TCM internal relay.

Effects:
MIL illuminated.
Transmission warning lamp illuminated.
Maximum fluid pressure applied.
Limp home mode applied.

Remedy: Renew TCM.





Troubleshooting Schematic

Key To Schematic Diagrams
1. Transmission Control Module (TCM)
2. Transmission Unit
3. TCM Multi-pin Connector
4. Transmission Rotary Switch
5. Transmission Connector Plug
6. Engine Control Module
7. Instrument Pack
8. ABS/Traction Control Control Module
9. Kickdown Switch