P2499 code meaning
EGR Cooler Bypass Position Sensor Circuit Low (Bank 2)
Powertrain system Generic code P24xx codes Check engine light
What P2499 means
P2499 stands for a bank 2 bypass position voltage that has fallen to the bottom of its range. No manufacturer documents the bank 2 code publicly. For orientation, GM's 2017 Duramax tables fail the bank 1 sensor (P2494) once its output drops under one percent of the supply and need 200 bad results out of 250 before the Type B fault is stored. A comparable bank 2 check would react to the same electrical causes: the signal wire grounded somewhere along the harness, the sensor supply interrupted or shorted, or a sensor that no longer drives its output. If other 5 V sensors report low values simultaneously, the shared reference circuit is the better starting point. High voltage on bank 2 is P249A, the bank 1 low code P2494.
P2499 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 3 hours
- Clears after repairAfter a drive cycle
Symptoms of P2499
- Check engine light on
- Bank 2 bypass position reads near zero
Common causes of P2499
- Most likelyBank 2 signal wire touching ground
- Possible5 V sensor supply interrupted or pulled down
- Less likelySensor output stage failed
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
EGR cooler bypass position sensor b2
What each part of P2499 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 4 | Area: auxiliary emission controls (catalytic converter, EGR, EVAP). |
| 99 | The exact fault in that area. |
What to do next
- Note P2499 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2499
What does P2499 mean?
P2499 means "EGR Cooler Bypass Position Sensor Circuit Low (Bank 2)". P2499 stands for a bank 2 bypass position voltage that has fallen to the bottom of its range. It is a generic code, so it means the same on every make.
Is it safe to drive with P2499?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P2499 fail an emissions test?
Yes, it can. P2499 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2499 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P2499 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.