P0606 — Control Module Processor Fault

What it means

The main processor of the engine control module failed its internal watchdog and plausibility checks, or the monitoring processor disagrees with the main one. For safety the module then shuts down its own outputs: throttle, injection and ignition can be limited or cut. Typical symptoms are limp home mode with reduced power, unwanted engine shutdown or a no start condition.

Likely causes (most common first)

1. Unstable supply voltage or a bad module ground causing processor resets
2. Corroded, wet or loose module connectors
3. Water ingress into the module, typically through a blocked plenum drain or a leaking bulkhead grommet
4. Failed or interrupted software update
5. Internal electronics failure: cracked solder joints, failed processor or power supply stage of the board

Can you drive with it?

Do not drive: power can be cut and the engine can stop in traffic without warning.