P064CGlow Plug Control Module 1
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- On diesels a glow plug control module switches the glow plugs (at Ford also the DEF heaters) with semiconductor switches, diagnoses itself and reports to the engine module. P064C means this module reports an internal fault. GM's 2017–18 Duramax checks for a switch that is commanded on but delivers less than 3.2 A and 0 V at the plug (3.5 s), ROM, RAM and EEPROM checksums, the charge pump of the high-side drivers and reverse polarity; the LML (2011–16) used under 6.6 A for 75 % of 4 s; lamp after two trips. Ford's 2023 diesels flag drivers that do not switch or overheat, a RAM checksum error, supply below 6.5 or above 16.5 V and module temperature above 125 °C, within about 1 s. The glow system then fails partly or completely: hard cold starts, white smoke and higher cold-start emissions.
- What you may notice
- Check engine and glow plug lamp
- Hard cold start, long cranking in cold weather
- White smoke and rough running after a cold start
- Glow plug circuit codes as well
- Likely causes
- LikelyGlow plug module faulty internally (switches, memory)
- PossibleInsufficient supply or ground (battery, corrosion, main fuse)
- PossibleShort in a glow plug or wire overloading a driver
- RareMoisture or corrosion in the connector of the engine-mounted module
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €150 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.