FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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ZF 4HP 16 - Automatic Transmission (European and N. American Emissions)




DTC P0603 (European and N. American Emissions)

Circuit Description

A normal function of the transmission control module (TCM) programming is to perform an internal check that verifies the integrity of the keep alive memory (KAM) memory allocations.

DTC P0603 sets when the KAM is not operating correctly when checked on initialization.

An area of KAM is failed a read/write test.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0603 Transmission Control Module (TCM) Long Term Memory Reset

Conditions for Setting the DTC

* The checksum of the current regulator data will be tested. If the checksum is not OK, then the error bit will be set.
* If writing to FLASH during power latch phase failed
* Each of the flash blocks has its own status which is located at the beginning of the each flash block and the status of the FLASH blocks do not fit together.
* System voltage is too high or too low.
* Transaxle input voltage is too high or too low.
* Immediately after the above condition occurs

Action Taken When the DTC Sets

* The malfunction indicator lamp (MIL) will illuminate.
* The TCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Failure Records buffer.
* Adopt Emergency/Substitute mode and constant 4th gear by hydraulic control.
* After ignition OFF/ON : 3rd gear by hydraulic control. Possible P, R and N also possible.
* Power supply cut off to the pressure control solenoid (PCS) valve.

Conditions for Clearing the MIL/DTC

* The MIL will turn OFF when the malfunction has not occurred after 3 ignition cycles.
* A history DTC will clear after 40 consecutive warm-up cycles.
* Using a scan tool can clear history DTCs.

Diagnostic Aids

When DTC P0603 sets, the possible cause of fault could be TCM.