P0606 — PCM Internal Processor Fault

P0606 is set when the engine control module's internal self-test detects an inconsistency in its own processor — typically a RAM test, ROM checksum, watchdog timeout, or processor brown-out. Unlike most OBD-II codes which point to an external sensor or actuator, P0606 is the PCM saying "something is wrong with me." The cause is usually a power or ground issue, water intrusion, or the PCM itself failing.

Severity: high powertrain Do not drive

Pick your vehicle for a P0606 diagnosis

Select your exact year, make, and model below to get a diagnostic guide tuned to your vehicle's known failure patterns and TSBs.

2010-2014

2015-2019

2020-2024