P2090 code meaning
"B" Camshaft Position Actuator Control Circuit Low (Bank 1)
Powertrain system Generic code P20xx codes Check engine light
What P2090 means
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.
P2090 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium, DIY possible
- Typical labor0.3 to 2 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2090
- Engine warning lamp on, immediately on some GM V6 engines
- Slightly higher consumption and emissions at part load
Common causes of P2090
- Most likelyExhaust valve control wire shorted to ground or engine block
- PossibleShorted coil in the exhaust oil control valve
- Less likelyDamaged or oil-soaked valve connector
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Oil control valve exhaust bank1Oil control valve wiringEngine control module
What each part of P2090 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 0 | Area: fuel and air metering and auxiliary emission controls. |
| 90 | The exact fault in that area. |
What to do next
- Note P2090 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 P2090
What does P2090 mean?
P2090 means ""B" Camshaft Position Actuator Control Circuit Low (Bank 1)". P2090 refers to actuator B, on engines with twin phasers the exhaust camshaft valve, on bank 1. It is a generic code, so it means the same on every make.
Is it safe to drive with P2090?
Drive gently and only to a workshop. With P2090 the car can go into limp mode (reduced power) to protect itself.
Will P2090 fail an emissions test?
Yes, it can. P2090 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 P2090 to fix?
Difficulty: medium. A typical repair takes 0.3 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P2090 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.