P22AD code meaning
O2 Sensor Positive Current Control Circuit High (Bank 1 Sensor 2)
Powertrain system Generic code P22xx codes Check engine light
What P22AD means
P22AD is the high-side fault on the positive current control line of the bank 1 downstream wide-band probe: the pump-current wire is pulled above its expected level, for example by contact with the heater feed or another supply wire. On Saab's 2010 9-5 the pump-current pins measure roughly 2.8 V at the plug, which gives a feel for the normal bias. GM lists the code in bulletin 21-NA-149 for the 3.0 Duramax LM2, again tied to engine harness chafing, but publishes no limit. Ford sends shorts to power on its upstream wide-band probes to P0132 instead of a dedicated code. The upstream analog is P2239 (Type B at Saab); P22AB is the open circuit, P22AC the low reading, P22BA the bank 2 version. The lamp is lit; driving normally feels unchanged.
P22AD 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 repairAfter a drive cycle
Symptoms of P22AD
- Check engine light
- Downstream oxygen reading implausibly high or fixed
- Readiness monitors for catalyst or aftertreatment not completed
Common causes of P22AD
- Most likelyPump-current wire shorted to the heater supply or another positive feed
- PossibleInternal short between heater and pump cell in the sensor
- Less likelyFaulty sensor interface in the ECM or sensor 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 P22AD 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). |
| AD | The exact fault in that area. |
What to do next
- Note P22AD 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 P22AD
What does P22AD mean?
P22AD means "O2 Sensor Positive Current Control Circuit High (Bank 1 Sensor 2)". P22AD is the high-side fault on the positive current control line of the bank 1 downstream wide-band probe: the pump-current wire is pulled above its expected level, for example by contact with the heater feed or another supply wire. It is a generic code, so it means the same on every make.
Is it safe to drive with P22AD?
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 P22AD fail an emissions test?
Yes, it can. P22AD 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 P22AD 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 P22AD 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.