Fuel Trim Long Term Fuel Trim Adaptive Limit Reached Bank 2 (GM)
What does P1169 mean?
The P1169 code means the vehicle's onboard diagnostic system has detected: Fuel Trim Long Term Fuel Trim Adaptive Limit Reached Bank 2 (GM). This is a moderate severity code.
Common Symptoms
- Check Engine Light on
- Decreased fuel economy
- Rough idle
- Engine hesitation or stumbling
- Possible misfires on Bank 2 cylinders
Probable Causes (Ranked by Likelihood)
- Vacuum leak affecting Bank 2 cylinders Very High
- Dirty or faulty MAF sensor High
- Clogged fuel injectors on Bank 2 Moderate
- Fuel delivery issue (weak pump or restricted filter) Moderate
- Bank 2 upstream O2 sensor failure Low
Step-by-Step Diagnostic Procedure
-
Compare Bank 1 and Bank 2 long-term fuel trim values -- if both are high, look for a common cause like MAF sensor
-
Smoke test for vacuum leaks, focusing on Bank 2 intake runners
-
Clean or replace the MAF sensor
-
Test fuel injector balance on Bank 2
-
Check fuel pressure under load
Frequently Asked Questions
If I have both P1168 and P1169, what should I check?
When both banks reach the adaptive limit simultaneously, the cause is likely something common to both banks: a dirty MAF sensor, low fuel pressure, or a large vacuum leak on the intake manifold (not bank-specific runners).
Can I reset fuel trims after a repair?
Yes. After repairing the cause of P1168/P1169, clear the codes with a scan tool. The fuel trims will reset to zero and the PCM will relearn correct values during normal driving. This typically takes 50 to 100 miles.
What is the difference between Bank 1 and Bank 2 on a GM V8?
On GM V8 engines, Bank 1 is the driver side (cylinders 1, 3, 5, 7) and Bank 2 is the passenger side (cylinders 2, 4, 6, 8). Each bank has its own O2 sensors and fuel trim control.