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
DIAGNOSTIC PROCEDURE - P0071-AMBIENT TEMP SENSOR PERFORMANCE
| TEST | ACTION |
|---|---|
| 1 | Ignition on, engine not running. With the DRBIII®, read DTCs and record the related Freeze Frame data. Is the Good Trip Counter displayed and equal to zero?
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| 2 |
NOTE:
Visually inspect both the component and the PCM connectors. Look for damage, partially broken wires and backed out or corroded terminals Turn the ignition off.Disconnect the Ambient Air Temp 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?
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| 3 | Turn the ignition off. Disconnect the Ambient Air Temperature Sensor harness connector. Ignition on, engine not running. With the DRBIII®, read the Ambient Air Temperature Sensor voltage. Is the voltage above 4.9 volts?
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| 4 | Turn the ignition off. Disconnect the Ambient Air Temperature Sensor harness connector. Using a jumper wire, jumper across the Ambient Air Temperature Sensor harness connector. Ignition on, engine not running. With the DRBIII®, read the Ambient Air Temperature voltage. Is the voltage below 1.0 volt?
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| 5 | Turn the ignition off. Disconnect the Ambient Air Temperature Sensor harness connector. Disconnect the PCM harness connector.
CAUTION:
DO NOT PROBE THE PCM HARNESS CONNECTORS. PROBING THE PCM HARNESS CONNECTORS WILL DAMAGE THE PCM TERMINALS RESULTING IN POOR TERMINAL TO PIN CONNECTION. INSTALL MILLER SPECIAL TOOL #8815 TO PERFORM DIAGNOSIS. Measure the resistance of the (K25) AAT Signal circuit from the Ambient Air Temperature Sensor harness connector to the appropriate terminal of special tool #8815. Is the resistance below 5.0 ohms?
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| 6 | Turn the ignition off. Disconnect the Ambient Air Temperature Sensor harness connector. Disconnect the PCM harness connector.
CAUTION:
DO NOT PROBE THE PCM HARNESS CONNECTORS. PROBING THE PCM HARNESS CONNECTORS WILL DAMAGE THE PCM TERMINALS RESULTING IN POOR TERMINAL TO PIN CONNECTION. INSTALL MILLER SPECIAL TOOL #8815 TO PERFORM DIAGNOSIS. Measure the resistance of the (K167) Sensor ground circuit from the Ambient Air Temperature Sensor harness connector to the appropriate terminal of special tool #8815. Is the resistance below 5.0 ohms?
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| 7 | Turn the ignition off. Disconnect the Ambient Air Temperature Sensor harness connector. Disconnect the PCM harness connector. Measure the resistance between ground and the (K25) AAT Signal circuit. Is the resistance below 100 ohms?
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| 8 | Turn the ignition off. Disconnect the Ambient Air Temperature Sensor harness connector. Disconnect the PCM harness connector. Measure the resistance between the (K25) AAT Signal circuit and the (K4) Sensor ground circuit in the Ambient Air Temperature Sensor harness connector. Is the resistance below 100 ohms?
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