Definition of the P0606 code
PCM processor error
What does code P0606 mean?
The power control module is sometimes referred to as the power control module or engine control module (ECM); all of these names mean the same thing. The PCM is responsible for controlling all aspects of the vehicle’s engine and electrical system.
When the vehicle is started, the PCM performs a self-test to ensure that all engine components are functioning properly. If the result of this self-test indicates a PCM processor failure, the PCM will register the diagnostic trouble code P0606.
What causes the P0606 code to occur?
- PCM wires that are damaged, corroded, and/or frayed.
- PCM connectors that are damaged, corroded, and/or worn out.
- Faulty PCM ground circuits and/or PCM output devices.
- Faulty CAN (Controller Area Network) bus communication.
What are the symptoms of the P0606 code?
- Check engine light is on
- The anti-lock braking system (ABS) light is on
- The vehicle stops or changes gear incorrectly.
- Vehicle may stall or change gear incorrectly
- Vehicle may exhibit symptoms of misfiring
- Increased fuel consumption
- Although rare, the symptoms may not be noticeable.
How can a mechanic diagnose the P0606 code?
- Retrieve frozen frame data using an OBD-II scanner. This will provide information on when the code was set by the PCM, as well as what likely caused the code to be stored.
- Visually inspect the wires and connectors leading to the PCM for breaks, frayed wires, and corroded connectors.
- After repairing or replacing damaged wires or connectors, retest the system. Most likely, the PCM will need to be replaced and/or reprogrammed.
- Check with your dealer to see if there is a recall or if the PCM can be replaced under the emissions warranty.
Frequent errors when diagnosing the P0606 code
- The diagnostic trouble code P0606 is difficult to diagnose; it is quite simple, and is usually an indication that the PCM needs to be replaced and/or reprogrammed.
- However, some of the symptoms are the same as for mechanical problems. Consequently, faulty repairs to ignition and/or fuel system components are common.
How serious is the P0606 code?
The PCM monitors and controls the operation of the vehicle’s engine and electrical system. The vehicle will not be able to operate without a properly functioning PCM. For this reason, this code can be considered one of the most serious codes.
What repairs can a P0606 code repair?
- Repair or replace any wires that are damaged and/or frayed.
- Repair or replace any damaged and/or corroded connectors.
- Repair or replace all damaged PCM ground circuits.
- Replace or reprogram the PCM.
Additional comments to consider for code P0606
Note that the symptoms of a defective PCM may be the same as those of a defective mechanical system. The P0606 troubleshooting code is simple and straightforward. However, it may be necessary to replace or reprogram the PCM at the dealer.
