Error P0606 – how to fix?

Code definition P0606

PCM processor error

What does the code P0606 mean?

The powertrain control module is sometimes referred to as a power control module or engine control module (ECM); all these names mean the same thing. The PCM is responsible for controlling all aspects of the vehicle’s engine and electrical system operation.

After starting the vehicle, the PCM performs a self-test to ensure that all engine components are functioning properly. If the result of this self-test indicates a fault in the PCM processor, the PCM will record a diagnostic trouble code P0606.

What causes the code P0606?

• PCM cables that are damaged, corroded, and / or frayed.
• PCM connectors that are damaged, corroded, and / or frayed.
• Faulty PCM ground circuits and / or PCM output devices
• CAN (Controller Area Network) communication defective

What are the symptoms of the P0606 code?

• The Check Engine light is on
• The anti-lock braking system (ABS) indicator comes on
• Vehicle stops or incorrectly shifts gears.
• The vehicle may stop or shift gears incorrectly
• The vehicle may experience misfiring symptoms
• Increased fuel consumption
• Although rare, symptoms may not be felt.

How can a mechanic diagnose the P0606 code?

• Downloading data from frozen frames using an OBD-II scanner. This will give you information on when the code was set by PCM, as well as what possibly caused the code to be saved.
• Visually inspect the wires and connectors leading to the PCM for breaks, frayed wires, and corroded connectors.
• After repairing or replacing damaged cables or connectors, retest the system. Most likely, you will need to replace and / or reprogram the PCM.
• Check with your dealer for any reminders or if the PCM can be replaced under the emissions warranty.

Common errors when diagnosing the P0606 code

• Diagnostic trouble code P0606 is hard to diagnose; this is fairly 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. As a result, incorrect repairs to components of the ignition and / or fuel system are often made.

How serious is the P0606 code?

The PCM monitors and controls the operation of the vehicle’s engine and electrical system. The vehicle cannot be operated without a properly functioning PCM. For this reason, this code can be considered one of the most serious codes.

What repairs can fix the code P0606?

1. Repair or replace any cords that are damaged and / or frayed.
2. Repair or replace any damaged and / or corroded connectors.
3. Repair or replace any damaged PCM ground circuits.
4. Replace or reprogram the PCM.

Additional considerations for code P0606

Note that symptoms of a faulty PCM can be the same as symptoms of a faulty mechanical system. Diagnostic trouble code P0606 is simple and uncomplicated. However, it may be necessary to replace or reprogram the PCM at your dealer.