P0605 Internal Control Module Read Only Memory (ROM) Error Trouble Code

P0605 Internal Control Module Read Only Memory (ROM) Error

OBD-II DTC Technical Description

Internal Control Module Read Only Memory (ROM) Error

What does that mean?

This diagnostic trouble code (DTC) is a generic powertrain code, which means that it applies to OBD-II equipped vehicles. Although generic, the specific repair steps may vary depending on make/model.

This trouble code basically means that the PCM/ECM (powertrain/engine control module) has detected an internal control module fault in the ROM (read only memory) in the PCM. The PCM is basically the vehicle's "electronic brain" that controls functions such as fuel injection, ignition, etc. When self-checks fail in the ROM, this DTC is set.

 

This code is a generic powertrain code. It is considered generic because it applies to all makes and models of vehicles (1996-newer), although specific repair steps may be slightly different depending on the model. A cursory search on the 'net shows this DTC to be more commonly found in Ford and Nissan vehicles.

Other internal control module error trouble codes include:

P0601 Internal Control Module Memory Check Sum Error P0602 Control Module Programming Error P0603 Internal Control Module Keep Alive Memory (KAM) Error P0604 Internal Control Module Random Access Memory (RAM) Error

Photo of a PCM with the cover removed:

Symptoms

Symptoms of a P0605 DTC will include MIL (malfunction indicator lamp) illumination, although there may be other symptoms including but not limited to various warning lights on dash, stalling, and no start conditions.

Potential Causes

There is an internal fault in the PCM / ECM Using an aftermarket performance programmer may trigger this code

Possible Solutions

In some cases, "flashing" the PCM with an updated software can fix this DTC. You will need acess to make & model specific information such as Technical Service Bulletins (TSBs).

If there are no PCM flash updates, the next step would be to check some wiring. Inspect and check for proper voltage and ground to the PCM and throughout the associated circuits. If there are problems with them, repair and retest.

If the wiring checks out OK, the next step is to replace the PCM, which is the most likely repair for this code. This is generally not a "do-it-yourself" task, although in some cases it may be. We strongly recommend you have a qualified repair shop / technician do the work, one that has the capability to reprogram the new PCM. Installing the new PCM may involve using special tools to program the vehicle's VIN (vehicle identification number) and/or anti-theft information (PATS, etc.).

As an alternative to replacing the PCM, some specialized shops may actually be able to repair the PCM. That may involve removing the PCM, shipping it off to them for repair, and re-installing it. That's not always an option for daily drivers.

NOTE: This repair may be covered under the emissions warranty so be sure to check with your dealer as this may be covered beyond the bumper-to-bumper or powertrain warranty period.

Other PCM DTC codes: P0600, P0601, P0602, P0603, P0604, P0606, P0607, P0608, P0609, P0610.

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