Upper Limit

ECM-261A LONG-TERM FUEL TRIM
UPPER LIMIT

Checking fuel injection system



Check intake system for air leakage according to Check For Air Leaks In the Intake System

Hint: Air leakage in the intake system can occur through the canister purge (CP) valve, the secondary air solenoid valve and power brake booster.

Check fuel pressure according to Checking Fuel and Residual Pressures

Test drive the car for approximately 10 minutes

Check the mass air flow (MAF) sensor by Read its correction factors. The value should be between 0.8 and 1.2

NOTE: There must not be any air leakage when this test is carried out.

Remedy as necessary.

Other information:
- To access/replace the Mass Air Flow (MAF) sensor, Mass Air Flow (MAF) Sensor, Replacing


Verification



Test drive the car according to the TRIP schedule, Monitors, Trips, Drive Cycles and Readiness Codes
Do not turn off engine after test drive.
Connect the car to VIDA again.
Read off fuel trim status.
There should not be any faults when fuel trim is finished.

Was a fault detected?
Yes - Continue below.
No - Testing Complete.


Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed. Exit fault tracing for this diagnostic trouble code (DTC) or make another attempt.