P0071

Test 1:

Test 2 - Test 5:

Test 6 - Test 8:

SYMPTOM
P0071-AMBIENT TEMP SENSOR PERFORMANCE

WHEN MONITORED
Engine off time is greater than 480 minutes. Ambient temperature is greater than 4° C (39° F).

SET CONDITION
After a calibrated amount of cool down time, the PCM compares the ECT Sensor, IAT Sensor and the Ambient Air Temperature Sensor values. If the Ambient Air Temperature Sensor value is not within 10° C (18° F) of the other two temperature sensors an error is detected. Two Trip Fault.

POSSIBLE CAUSES
- Good trip equal to zero
- (K25) AAT signal circuit shorted to battery voltage
- Ambient air temperature sensor voltage below 1.0 volt
- (K25) AAT signal circuit open
- (K4) Sensor ground circuit open
- (K25) AAT signal circuit shorted to ground
- (K25) AAT signal circuit shorted to (K4) sensor ground
- PCM low
- PCM high