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Home >> Jeep >> 2005 >> Wrangler Rubicon, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 543 (Engine Controls - DTCS P0016 To P0118, Diagnostic Code Index, Pre-Diagnostic Troubleshooting, Intermittent Condition) >> Diagnosis And Testing >> P0112-Intake Air Temperature Sensor Circuit Low >> Diagnostic Test

Diagnostic Test

WARNING: This page is about a different car, the 2005 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.
  1. 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 

    1. Go To step  2).

    No 

    1. Refer to INTERMITTENT CONDITION .
    2. Perform POWERTRAIN VERIFICATION TEST .
  2. 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 

    1. Replace the Intake Air Temperature Sensor.
    2. Perform POWERTRAIN VERIFICATION TEST .

    No 

    1. Go To step  3).
  3. 3)  (K21) IAT SIGNAL SHORTED TO GROUND 
    Fig 1: Checking IAT Signal Circuit Shorted to Ground
    GC0002662Courtesy of DAIMLERCHRYSLER CORP.

    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 

    1. Repair the short to ground in the (K21) IAT Signal circuit.
    2. Perform POWERTRAIN VERIFICATION TEST .

    No 

    1. Go To step  4).
  4. 4)  (K21) IAT SIGNAL SHORTED TO THE (K900) SENSOR GROUND CIRCUIT 
    Fig 2: Checking IAT Signal Circuit Shorted to Sensor Ground Circuit
    GC0002658Courtesy of DAIMLERCHRYSLER CORP.

    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 

    1. Repair the short between the (K900) Sensor ground circuit and the (K21) IAT Signal circuit.
    2. Perform POWERTRAIN VERIFICATION TEST .

    No 

    1. Go To step  5).
  5. 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 

    1. Repair as necessary.
    2. Perform POWERTRAIN VERIFICATION TEST .

    No 

    1. Replace and program the Powertrain Control Module per Service Information.
    2. Perform POWERTRAIN VERIFICATION TEST .
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