P2189: Mixture too lean at idle (bank 2)
At idle, bank 2 has too much air or too little fuel. The usual cause is an air leak from a vacuum hose or gasket on that side of the engine.
| Code | P2189 |
|---|---|
| System | Engine and transmission |
| Group | P21xx, Throttle, injection and emissions |
| Type | Generic: it means the same on every make |
| Can you keep driving? | With care |
What P2189 means
At idle, the ECU adds a lot of fuel on bank 2 and hits its limit. It only exists on engines with two banks, such as V6 or V8 units. Bank 2 is the side opposite cylinder 1.
Most common causes
- Split or loose vacuum hose near bank 2
- Intake manifold gasket leaking on the bank 2 side
- Broken crankcase ventilation (PCV) valve or hose
- Dirty bank 2 injectors
- Exhaust leak ahead of the bank 2 oxygen sensor
- Low fuel pressure (if bank 1 is lean as well)
Symptoms
- Engine warning light on
- Rough idle
- Hissing sound from the engine bay
- Tendency to stall
Can you drive with P2189?
With care The car can be driven, but find the leak soon so it does not turn into misfires.
Open the bonnetthe in-depth explanation
How to check it
Compare fuel trims for both banks at idle. If only bank 2 is strongly positive and improves as revs rise, the leak is on that side; if both are high, check fuel pressure first.
How to read and clear P2189 with Final OBD
Plug an OBD2 scanner in under the steering wheel, switch the ignition on and open Final OBD. Under Faults you’ll see P2189 with its description and whether it’s confirmed, pending or permanent.
If the engine stores it over standard OBD, with FREE you read this code with its explanation for nothing and clear it. With PRO you also read the faults of every control unit and clear them in all of them.
Clearing the code only turns the light off: if the cause is still there, it comes back. Clear it once it’s fixed, and not right before an inspection. It’s all in how to read and clear fault codes and in inspections and OBD.
Similar codes
- P2185 The engine 2 coolant temperature sensor gives a higher signal than normal
- P2186 The engine 2 coolant temperature sensor fails now and then
- P2187 Mixture too lean at idle (bank 1)
- P2188 Mixture too rich at idle (bank 1)
- P218A The throttle actuator B control system idle position needs its learning
- P218C Throttle or fuel inhibit circuit B operates out of range or performs incorrectly
- P218D The throttle or fuel inhibit circuit B signal is low
- P218E The throttle or fuel inhibit circuit B signal is high
- P2100 Throttle actuator A control motor circuit open
- P2101 Throttle actuator A control motor circuit range or performance
- P2102 Throttle actuator A control motor circuit low
- P2104 Throttle control system: forced idle
What does code P2189 mean?
At idle, the ECU adds a lot of fuel on bank 2 and hits its limit. It only exists on engines with two banks, such as V6 or V8 units. Bank 2 is the side opposite cylinder 1.
Can you drive with P2189?
The car can be driven, but find the leak soon so it does not turn into misfires.
How do you clear P2189?
With an OBD2 scanner and an app like Final OBD, which clears it for free if it’s stored by the engine control unit. But clearing it only turns the light off: if the cause isn’t fixed, P2189 comes back.
Read it on your car
Final OBD reads and clears engine faults through standard OBD for free, each one explained in plain English. With PRO it also reads the faults of every control unit, each make’s own codes included, and clears them in all of them.
