P2189 on 2008-2011 Buick Enclave — System Too Lean at Idle (Bank 2)
1 vehicles · 1 makes
Most Reported On
P2189 is an OBD-II diagnostic trouble code meaning “System Too Lean at Idle (Bank 2).” P2189 means the engine computer detected that the air-fuel mixture on bank 2 is running too lean (too much air relative to fuel) specifically at idle. The computer watches the oxygen sensors and has been adding extra fuel (high fuel trim) to compensate, but the correction has reached its limit, indicating an unmetered air leak or a fuel-delivery shortfall. A lean condition at idle commonly causes rough idle, stalling, hesitation, or a surging engine. The usual culprits are vacuum/intake leaks downstream of the airflow sensor or anything restricting fuel. This code is most commonly reported on 2008-2011 Buick Enclave.
Common Causes
Diagnostic Tools
To diagnose P2189, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
- Read & clear engine codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X OBD-II Scanner
by LAUNCH
A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
As an Amazon Associate, we earn from qualifying purchases. Prices are approximate and may vary.
FAQ
What does P2189 mean?
P2189 stands for "System Too Lean at Idle (Bank 2)." P2189 means the engine computer detected that the air-fuel mixture on bank 2 is running too lean (too much air relative to fuel) specifically at idle. The computer watches the oxygen sensors and has been adding extra fuel (high fuel trim) to compensate, but the correction has reached its limit, indicating an unmetered air leak or a fuel-delivery shortfall. A lean condition at idle commonly causes rough idle, stalling, hesitation, or a surging engine. The usual culprits are vacuum/intake leaks downstream of the airflow sensor or anything restricting fuel.
What are the most common causes of P2189?
The most common causes of P2189 are: Vacuum or intake manifold air leak (gaskets, hoses, PCV), Dirty or faulty mass airflow (MAF) sensor, Clogged or weak fuel injectors on bank 2, Low fuel pressure (failing pump, restricted filter, weak regulator), Leaking intake gasket or cracked intake boot, Faulty or contaminated oxygen sensor giving false lean signal, Exhaust leak ahead of the upstream O2 sensor. The specific cause varies by vehicle.
How much does it cost to fix P2189?
Repair costs vary widely depending on the root cause and vehicle.
Which vehicles are affected by P2189?
Au7o has documented P2189 across 1 vehicle models from 1 manufacturers: Buick.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.