P2B99
Exhaust Pressure Control Valve A Driver Current/Temperature Too High
The output driver for the exhaust pressure control valve A reports current or junction temperature above its protection threshold. Stalled actuator or short-circuit fault.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: hard
Common causes
Ordered by how often each turns out to be the cause.
- Valve actuator mechanically jammedCommon
- Control wire shorted to groundPossible
Parts involved
- Exhaust Pressure Control Valve A
- ECM
P2B99 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.