OBD-II code · Powertrain (generic, extended)
P2DA4 Coolant Heater A Internal Control Module Performance
The internal control module of coolant heater A reports a performance fault. Internal self-tests fail.
Is it safe to drive with P2DA4?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyInternal module fault
- PossibleFirmware corruption
- Less likelyModule software outdated, reflash may resolve
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
- Best left to a mechanic
- Typical labour
- 1–5 h
- Emissions test
- Usually unaffected
- Parts involved
- Coolant Heater A, Coolant Heater A Control Module
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.