P2090"B" Camshaft Position Actuator Control Circuit Low (Bank 1)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P2090 refers to actuator B, on engines with twin phasers the exhaust camshaft valve, on bank 1. What Low means depends on how the ECM drives the solenoid. GM's usual high-side output flags a ground short while the valve is energised; the 3.6 L LFX V6 (19OBDG03B) sets P2090 after 20 of 25 samples as Type A, the 2018 hybrid table 18OBDG02 as Type B. A GM controller with a low-side driver in table 23OBDG07 flips the test: it looks for a low voltage while the output is off and flags the code after only 0.2 s, two trips to the lamp. In both cases the threshold is below 0.5 ohms to ground. An open line on this valve is P0013, not P2090. With the exhaust phaser parked, the engine loses some internal exhaust recirculation and part-load efficiency.
- What you may notice
- Engine warning lamp on, immediately on some GM V6 engines
- Slightly higher consumption and emissions at part load
- Likely causes
- LikelyExhaust valve control wire shorted to ground or engine block
- PossibleShorted coil in the exhaust oil control valve
- RareDamaged or oil-soaked valve connector
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €30 – €350
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.