Aisin 81-40LE - Automatic Transmission

DTC P0604

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0604 Control Module Random Access Memory (RAM)

Conditions for Setting the DTC

* The transmission control module (TCM) cannot carry out the 4 random access memory (RAM) initialization routines.
* The TCM detects that the RAM cannot be written and read correctly.

Action Taken When the DTC Sets

The TCM will request the illumination of the Hold/Malfunction Indicator Lamp (MIL) and store the DTC when the TCM detects failures on 2 consecutive ignition cycles.

Conditions for Clearing the DTC

* The TCM turns OFF the Hold/Malfunction Indicator Lamp (MIL) when no further failures are detected on the next ignition cycles.
* The scan tool can clear the DTC from the TCM history.
* The TCM clears the DTC from the TCM history memory after 40 consecutive ignition cycles without fault.

Cause of Failure

* The harness or connector between the TCM and the engine control module (ECM)
* The ECM
* The TCM