P0112-INTAKE AIR TEMPERATURE SENSOR CIRCUIT LOW
For a complete wiring diagram Refer to Section 8W.
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When Monitored:
With the ignition on and battery voltage greater than 10.4 volts.
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Set Condition:
When the Inlet Air Temp Sensor Signal circuit voltage is less than .078 volt for more than 2.8 seconds. One trip failure. Three good trips to clear the MIL.
Possible Causes
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(K21) IAT SIGNAL SHORTED TO GROUND
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(K21) IAT SIGNAL SHORTED TO THE (K900) SENSOR GROUND CIRCUIT
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INTAKE AIR TEMPERATURE SENSOR
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PCM
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Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.
(Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).
Diagnostic Test
1.
IAT SENSOR VOLTAGE BELOW 0.078 OF A VOLT
Ignition on, engine not running.
With a scan tool, read the IAT voltage.
Is the voltage below 0.078 of a volt?
Yes
No
2.
IAT SENSOR
Turn the ignition off.
Disconnect the IAT Sensor harness connector.
Ignition on, engine not running.
With a scan tool, read IAT voltage.
Is the voltage above 0.05 of a volt?
Yes
No
3.
(K21) IAT SIGNAL SHORTED TO GROUND
Turn the ignition off.
Disconnect the C2 PCM harness connector.
Measure the resistance between ground and the (K21) IAT Signal circuit in the IAT Sensor harness connector.
Is the resistance below 100 ohms?
Yes
No
4.
(K21) IAT SIGNAL SHORTED TO THE (K900) SENSOR GROUND CIRCUIT
Measure the resistance between the (K21) IAT Signal circuit and the (K900) Sensor ground circuit in the IAT Sensor harness connector.
Is the resistance below 100 ohms?
Yes
No
5.
PCM
NOTE:
Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.
Were there any problems found?
Yes
No