P050B

Test 1:

Test 2-5:

Test 6-8:

Test 9-12:

SYMPTOM
P050B-COLD START IGNITION TIMING PERFORMANCE

WHEN MONITORED
Cold start condition. Ambient Air temperature between -7 deg C and 50 deg C. The difference between Ambient Air temp and ECT signals at Start is equal to or less than 10 deg C. Engine running at idle only.

SET CONDITION
Engine RPM is 50 RPM or more (depending on vehicle specifications), below idle speed for at least 3 seconds and the average spark advance is above the threshold, too much spark advance, for a specified time limit. Two trip fault. Three good trips to turn off the MIL.

POSSIBLE CAUSES
- (K61) IAC motor control circuit open
- (K61) IAC motor control circuit shorted to ground
- (K961) IAC return circuit open
- (K961) IAC return circuit shorted to ground
- Good trip equal to zero
- Throttle plate inspection
- Dirty air filter
- Fuel contamination
- Excessive resistance in the (K60) IAC signal circuit
- Excessive resistance in the (K39) IAC motor control circuit
- IAC motor
- PCM