P22C2 code meaning
O2 Sensor Pumping Current Trim Circuit/Open (Bank 2 Sensor 2)
Powertrain system Generic code P22xx codes Check engine light
What P22C2 means
P22C2 reports an open trim line on the bank 2 downstream wide-band probe. Every probe ships with a calibration resistor in its plug (pin 5, RT/IA on a Bosch LSU) that corrects for spread in its diffusion gap; on Bosch probes it sits in parallel with the controller's sense resistor. Ford explains that if it opens, all pump current is forced through that measuring resistor, tilting the lambda curve, a small error near stoichiometry. No maker documents P22C2 publicly. Upstream on bank 2 it is P2629: VW's 2014 Touareg triggers above 4.81 V, Saab tests P2626 during overrun below 750 C, and Ford bulletin 17-2124 replaces the front probes of the 3.5 GTDI for P2626/P2629. P22C3/P22C4 are low/high, P22B5 bank 1. The lamp lights.
P22C2 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2 hours
- Clears after repairAfter a drive cycle
Symptoms of P22C2
- Check engine light
- Bank 2 downstream lambda reads slightly off, most visibly away from lambda 1
Common causes of P22C2
- Most likelyCorroded or loose trim-resistor terminal in the sensor plug
- PossibleTrim resistor or its lead open inside the sensor connector
- Less likelyTrim wire broken between connector and control module
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Oxygen sensor bank2 sensor2Oxygen sensor wiringECM
What each part of P22C2 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 2 | Area: fuel and air metering (injector circuit). |
| C2 | The exact fault in that area. |
What to do next
- Note P22C2 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 P22C2
What does P22C2 mean?
P22C2 means "O2 Sensor Pumping Current Trim Circuit/Open (Bank 2 Sensor 2)". P22C2 reports an open trim line on the bank 2 downstream wide-band probe. It is a generic code, so it means the same on every make.
Is it safe to drive with P22C2?
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 P22C2 fail an emissions test?
Yes, it can. P22C2 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 P22C2 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P22C2 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.