What it means
The IMRC position sensor on bank 2 reports a voltage above the upper threshold — usually a short to positive or an open ground.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The bank 2 IMRC position sensor reports runner position to the control module through a signal circuit. P2021 sets when the signal voltage is above the circuit's allowed threshold, which can occur with a signal short to positive, an open sensor ground, or a poor high-resistance connector; despite the code title, the supplied meaning describes a high signal condition.
Common causes
Most likely first.
- Signal shorted to positive
- Sensor ground open
- Connector pins corroded - high contact resistance
Symptoms
- Check-engine light
- Possible reduced engine performance
- Possible rough running or hesitation
How to diagnose it
- Capture freeze-frame data and check the bank 2 runner position reading and related sensor codes before clearing the fault.
- Inspect the bank 2 position sensor connector and harness for corrosion, loose terminals, or a signal wire contacting a power feed.
- Check continuity of the bank 2 sensor ground and inspect its connector terminals for an open or excessive resistance.
- Measure the bank 2 signal and reference circuits while connected, comparing readings with the manufacturer's specification to locate an over-high signal.
- Isolate the sensor from the harness and test the signal circuit for a short to positive before deciding whether the sensor itself has failed.
Common fixes
- Repair a bank 2 signal wire shorted to a power feed.
- Restore the open or poor ground at the bank 2 position sensor.
- Clean or replace corroded bank 2 connector terminals that create high contact resistance.
- Replace the bank 2 position sensor only if its output remains incorrect with the ground and wiring verified.
Can I keep driving?
A cautious short drive is generally possible if the engine remains smooth, but hesitation or reduced performance can make acceleration less reliable. Avoid hard acceleration and fix the high bank 2 sensor signal soon to prevent continued runner-control and emissions problems.
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.