P2AB1Catalyst Heater Control Module Performance
- 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
- P2AB1 reports that the control module of an electrically heated catalyst does not work as it should, for example because its self-test fails or the heating it delivers does not match the demand. Such heaters bring a catalyst to working temperature right after start or in low-load driving. According to DieselNet, Vitesco's Emicat heating disc went into two 48-volt mild-hybrid diesel van models from 2022 to warm up the SCR catalyst, after an earlier small-scale use on Audi's 3.0 TDI from model year 2014. No manufacturer documents P2AB1 publicly. CARB requires heated catalysts to reach their design temperature within a period the manufacturer sets after start. A failed switching stage or corrupt software are plausible causes; circuit faults of the heater itself are P0429 and P0439.
- What you may notice
- Check engine light on
- Higher emissions after cold start; inspection may fail
- Driving behaviour largely unchanged
- Likely causes
- LikelyInternal fault in the heater control module (power stage or self-test)
- PossibleModule software fault, update may be available
- RareModule overheated due to poor cooling or high ambient heat at its mounting
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €100 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.