P064C

Symptoms

• Check Engine light comes on
• Long or difficult cold start of a diesel engine
• White or blue smoke on cold start
• Unstable engine operation when warming up
• Glow plug indicator does not go out or light up

Causes

• Glow Plug Control Module (GPCM) internal fault
• Lost communication between ECU and GPCM
• GPCM module power or ground failure
• Malfunction of the glow plugs themselves (module overload)
• ECU malfunction (rare)

How to Fix

1. Check the operation of the glow plugs (current during warm-up should be 8–15 A per plug)
2. Check power and ground of GPCM module
3. Inspect the wiring between the ECU, GPCM and spark plugs
4. Measure the resistance of each glow plug (good: 0.5-2 ohms)
5. Diagnostics of the GPCM module with a specialized scanner
6. If there is a malfunction, replace the GPCM module or glow plugs

Related codes

Error P064C by Vehicle Brand