P22B5 code meaning
O2 Sensor Pumping Current Trim Circuit/Open (Bank 1 Sensor 2)
Powertrain system Generic code P22xx codes Check engine light
What P22B5 means
P22B5 flags an open trim line on the bank 1 downstream wide-band probe. Bosch LSU probes carry a trimming resistor in the connector module, wired to pin 5 (RT/IA), that sets each sensor's individual characteristic; the controller reads it to scale the measured pump current. Lose that line and the oxygen value can still move, but with the wrong gain. Chrysler's wording speaks of the pump cell current trim of sensor 1/2 and lists the code for 2010-2012 Ram 2500/3500 with the 6.7 Cummins; after the wiring repair its road test compares both sensors during 10-second fuel cut-offs and allows no more than 4 % difference. Saab's upstream analog P2626 is checked in overrun below 750 °C and sets above 4.81 V. P22B6/P22B7 are low/high, P22C2 bank 2.
P22B5 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P22B5
- Check engine light
- Downstream oxygen reading disagrees with the upstream sensor during fuel cut-off
- Follow-up aftertreatment or catalyst faults possible
Common causes of P22B5
- Most likelyCorroded or loose trim-line terminal in the sensor connector
- PossibleTrim wire broken between sensor connector and ECM or sensor module
- Less likelyOpen trimming resistor in the sensor's connector module
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Oxygen sensor bank1 sensor2Oxygen sensor wiringECM
What each part of P22B5 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). |
| B5 | The exact fault in that area. |
What to do next
- Note P22B5 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 P22B5
What does P22B5 mean?
P22B5 means "O2 Sensor Pumping Current Trim Circuit/Open (Bank 1 Sensor 2)". P22B5 flags an open trim line on the bank 1 downstream wide-band probe. It is a generic code, so it means the same on every make.
Is it safe to drive with P22B5?
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 P22B5 fail an emissions test?
Yes, it can. P22B5 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 P22B5 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P22B5 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.