P2189 code meaning
System Too Lean at Idle (Bank 2)
Powertrain system Generic code P21xx codes Check engine light
What P2189 means
P2189 is the bank 2 version of P2187: on engines with a front oxygen sensor per bank, the long-term trim of bank 2 has to add more fuel than allowed at idle and low load. GM's 2005 2.8 and 3.6 V6 set it when the additive correction exceeds 7 %, the 2008 3.6 LLT above 6.1 % at 520 to 1120 rpm, airflow of 1.7 to 7.8 g/s, engine load of 11 to 45 % and coolant above 60 °C, and GM's 2024 tables above about 5.5 % over two trips. Because both banks share the throttle, crankcase ventilation and brake booster vacuum, a leak there normally lifts the idle trim on both banks, setting P2187 and P2189 together. A code on bank 2 alone points to something only that bank sees: an intake manifold gasket or runner leak on that side, an injector on that bank, or the bank 2 front sensor or its wiring. Comparing both banks' trims at idle and at 2500 rpm narrows it down.
P2189 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2189
- Malfunction indicator lamp on
- Rough or hunting idle
Common causes of P2189
- PossibleIntake gasket or runner leak on the bank 2 side
- PossibleShared vacuum leak, usually with P2187 present too
- Less likelyBank 2 front sensor, its wiring or an injector on that bank
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Intake manifoldIntake manifold gasketFuel injectorOxygen sensor upstream
What each part of P2189 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 1 | Area: fuel and air metering. |
| 89 | The exact fault in that area. |
What to do next
- Note P2189 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 P2189
What does P2189 mean?
P2189 means "System Too Lean at Idle (Bank 2)". P2189 is the bank 2 version of P2187: on engines with a front oxygen sensor per bank, the long-term trim of bank 2 has to add more fuel than allowed at idle and low load. It is a generic code, so it means the same on every make.
Is it safe to drive with P2189?
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 P2189 fail an emissions test?
Yes, it can. P2189 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 P2189 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P2189 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.