OBD-II code · Powertrain (generic, extended)
P249A EGR Cooler Bypass Position Sensor Circuit High Bank 2
Same as P2495 on bank 2. EGR mixes inert exhaust into intake to lower combustion peak temperature — too little raises NOx, too much causes misfires and rough running.
Is it safe to drive with P249A?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySignal shorted to supply
- Less likelyConnector pins corroded - high contact resistance
- Less likelySupply wire pinched against B+ source
Symptoms
- Check engine light on
- Pinging or knocking under load
- Power loss and hesitation
- Possible rough idle
- Failed emissions inspection (NOx)
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.8–2 h
- Emissions test
- Likely to fail
- Parts involved
- Egr Cooler Bypass Position Sensor B2
Related codes
- P2495EGR Cooler Bypass Position Sensor Circuit High Bank 1
- P2497EGR Cooler Bypass Position Sensor Circuit Bank 2
- P2498EGR Cooler Bypass Position Sensor Range or Performance Bank 2
- P2499EGR Cooler Bypass Position Sensor Circuit Low Bank 2
- P249BEGR Cooler Bypass Position Sensor Circuit Intermittent or Erratic Bank 2
- P249CExcessive Time To Enter Closed Loop Reductant Injection Control
- P249DClosed Loop Reductant Injection Control At Limit Flow Too Low
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.