P06F8

Symptoms

• Check Engine light on
• No communication with GPCM2 on the scanner
• Spark plugs of the second group do not warm up
• Difficult cold starting of diesel
• Unstable engine operation after a cold start

Causes

• Broken wire of the ECU-GPCM2 control line
• Closing the control wire with the power circuit
• Oxidation of GPCM2 connector contacts
• Internal fault GPCM2 (input circuit break)
• Mechanical damage to the wiring harness

How to Fix

1. Inspect the wiring harness from the ECU to GPCM2 for breaks and damage
2. Check the contacts of the GPCM2 connector for oxidation
3. Measure the resistance of the control wire from the ECU to GPCM2 (with the units disconnected)
4. Repair the break or restore contact in the connector
5. If there is a short circuit to “plus”, find the location of the short circuit and eliminate it
6. If there is an internal fault in GPCM2, replace the module

Related codes

Error P06F8 by Vehicle Brand