OBD-II code · Powertrain (generic)
P0640 Intake Air Heater Control Circuit
A general circuit fault on the intake air heater control - the ECU cannot drive the grid heater at cold-start.
Is it safe to drive with P0640?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyOpen in heater or wiring
Symptoms
- Check engine light on
- Possible limp mode or no-start
- Multiple follow-up faults across modules
- Reset/relearn may be needed after repair
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.6–2 h
- Emissions test
- Likely to fail
- Parts involved
- Intake Air Heater
Related codes
- P063DGenerator Voltage Sense Circuit A High
- P063EAuto Configuration Throttle Input Not Present Bank 1
- P063FAuto Configuration Engine Coolant Temperature Input Not Present
- P0641Sensor Reference Voltage "A" Circuit Open
- P0642Sensor Reference Voltage "A" Circuit Low
- P0643Sensor Reference Voltage "A" Circuit High
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.