PowertrainP1A9B
CautionSeverity: Caution - get it checked when you can
Change ID (CMU 01)
Key terms: Control module: a small computer that runs one part of the car · Powertrain: engine, transmission and emissions
1What it means in plain English
The engine or powertrain control system has stored a fault that does not have specific guidance in this database yet.
2Common causes
- Sensor or actuator fault
- Wiring or connector fault
- Vacuum or intake leak
- Fuel or ignition problem
- Control module fault
3Can I drive?
Have it diagnosed promptly. If the car runs and drives normally, drive gently to a workshop. If it runs badly, stalls, overheats, loses oil pressure, or a warning light is flashing or red, stop safely and get professional help. If the code concerns the brakes, brake vacuum or brake assist, do not drive until it is checked: a hard pedal or longer stopping distance means stop.
This page gives general information. It is not professional advice. For a definite diagnosis and a repair quote, ask a qualified mechanic to inspect the car.
4Brand data 14
| Brand | Code | Description | System |
|---|---|---|---|
| BYD | P1A9B | Rear impact hardwire signal PWM abnormal warning Brand | Powertrain |
| Chery | P1A9B | Engine Idle starting failure due to starting timeout Brand | Powertrain |
| Chrysler | P1A9B | No description available | Powertrain |
| Daewoo | P1A9B | No description available | Powertrain |
| EOBD | P1A9B | Endre ID Brand | Powertrain |
| GM | P1A9B | No description available | Powertrain |
| Holden | P1A9B | Integrated Starter Control Module Malfunction Brand | Powertrain |
| Mitsubishi | P1A9B | Change ID Brand | Powertrain |
| Opel | P1A9B | No description available | Powertrain |
| Peugeot | P1A9B | No description available | Powertrain |
| Proton | P1A9B | Change ID Brand | Powertrain |
| Saab | P1A9B | No description available | Powertrain |
| MG (SAIC) | P1A9B | HCU Report ISC Fault Brand | Powertrain |
| Toyota | P1A9B | Change ID (CMU 01) Brand | Powertrain |
Legend: SAE is the generic J2012 description; Brand is text taken from that manufacturer’s data. Manufacturer rows keep the wording and language of the source data, and non-English text is tagged so screen readers pronounce it correctly.
5Related codes
Browse Pxxx codes or P1A9xx codes.