Diagnostic Aids
Inspect for the following conditions:
- An incorrectly routed harness. Inspect the harness of the MAF sensor in order to verify that the harness is not routed too close to the following components:
- The secondary ignition wires or coils.
- Any solenoids.
- Any relays.
- Any motors.
- A low minimum air rate through the sensor bore may cause this DTC to set at idle or during deceleration. Inspect for any vacuum leak downstream of the MAF sensor.
- A skewed or stuck TP sensor.
- A Wide Open Throttle (WOT) acceleration from a stop should cause the MAF sensor g/s display on the scan tool to increase rapidly. This increase should be from 4-7 g/s at idle to 150 g/s or more at the time of the 1-2 shift. If the increase is not observed, inspect for a restriction in the induction system or the exhaust system.
- The Barometric (BARO) pressure that is used in order to calculate the predicted MAF value is initially based on the MAP sensor at key ON. When the engine is running the MAP sensor value is continually updated near Wide Open Throttle (WOT). A skewed MAP sensor will cause the calculated MAF value to be inaccurate. The value shown for the MAP sensor display varies with the altitude. With the ignition on and the engine off, 103 kPa is the approximate value near sea level. This value will decrease by approximately 3 kPa for every 1,000 feet (305 meters) of altitude.
- High resistance on the ground circuit of the MAP sensor can cause this DTC to set.
- Any loss of vacuum to the MAP sensor can cause this DTC to set.
If the problem is intermittent, See INTERMITTENT CONDITIONS under SELF-DIAGNOSTIC SYSTEM.