What it means
Drive voltage to the exhaust VVT oil control valve on bank 1 is above the upper limit. Mirror image of P2089 on the exhaust cam side.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The bank 1 exhaust camshaft actuator uses an oil control valve to direct engine oil to the cam phaser and change exhaust valve timing. The control module monitors the valve's electrical drive circuit and sets P2091 when it detects a voltage higher than its upper limit.
Common causes
Most likely first.
- Drive line shorted to supply
- ECU driver stage failed
- Connector pins corroded - high contact resistance
Symptoms
- Check engine light on
- Power loss especially in mid-rpm range
- Possible rough idle or stalling
- Increased fuel consumption
How to diagnose it
- Save freeze-frame data and check live cam timing and actuator command data to see when the bank 1 exhaust actuator circuit fault occurs.
- Inspect the bank 1 exhaust oil control valve connector and wiring for corrosion, damaged insulation, or contact with a power feed.
- Check the connector terminals for corrosion or poor contact that could increase resistance in the circuit.
- With the circuit isolated as specified by the manufacturer, check whether the actuator drive wire is shorted to a supply voltage.
- If the wiring and valve check out, have the control module's bank 1 exhaust actuator driver tested against the manufacturer's procedure.
Common fixes
- Clean or repair corroded or loose bank 1 exhaust actuator connector terminals.
- Repair wiring shorted to a supply voltage in the bank 1 exhaust actuator circuit.
- Replace a faulty bank 1 exhaust oil control valve if its electrical test fails.
- Repair or replace the control module only if its actuator driver is confirmed faulty.
Can I keep driving?
If the engine runs smoothly, a short, gentle drive may be possible, but avoid hard acceleration because exhaust cam timing may not respond correctly and power or fuel economy can worsen. Stop if it stalls, runs very roughly, or loses significant power.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.