Symptom:
P0073-AMBIENT TEMP SENSOR HIGH
When Monitored and Set Condition:
P0073-AMBIENT TEMP SENSOR HIGH
When Monitored: The ignition key on.
Set Condition: The Ambient Temperature Sensor voltage is greater than 4.94 volts. One
Trip Fault.
POSSIBLE CAUSES
AMBIENT AIR TEMPERATURE SENSOR VOLTAGE ABOVE 4.8 VOLTS
(K25) AAT SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE
AMBIENT AIR TEMPERATURE SENSOR INTERNAL FAILURE
(K25) AAT SIGNAL CIRCUIT OPEN
(K4) SENSOR GROUND CIRCUIT OPEN
PCM
TEST ACTION APPLICABILITY
1 Ignition on, engine not running.
With the DRBIIIt, read the Ambient Air Temperature Sensor voltage.
Is the voltage above 4.8 volts?
All
Yes → Go To 2
No → Refer to the INTERMITTENT CONDITION symptom in the
Driveability category.
Perform POWERTRAIN VERIFICATION TEST VER-5-NGC.
2 Turn the ignition off.
Disconnect the Ambient Air Temperature Sensor harness connector.
Ignition on, engine not running.
Measure the voltage of the (K25)AAT Signal circuit in the Ambient Air Temperature
Sensor harness connector.
Is the voltage above 5.2 volts?
All
Yes → Repair the short to battery voltage in the (K25) AAT Signal
circuit.
Perform POWERTRAIN VERIFICATION TEST VER-5-NGC.
No → Go To 3
51
DRIVEABILITY - NGC