Diagnostic Test

DTC IS ACTIVE
1. Start the engine and allow it to reach normal operating temperature.
  WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury.
2. With the scan tool, select View DTCs.
  Is the status Active for this DTC?
  
  Yes
  - Go to step 2
  No
  - Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure
(K21) IAT SIGNAL CIRCUIT SHORTED TO VOLTAGE

Fig 1: Checking IAT Signal Circuit
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the Intake Air Temperature Sensor connector.
3. Disconnect the Powertrain Control Module (PCM) connector.
4. Turn the ignition on.
5. Measure the voltage of the (K21) IAT Signal circuit in the Intake Air Temperature Sensor harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the (K21) IAT Signal circuit for a short to voltage.
  - Perform the PCM Verification Test. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Go to step 3
(K21) IAT SIGNAL OPEN OR HIGH RESISTANCE

Fig 2: Checking IAT Signal Circuit
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
  NOTE: When checking circuits at the Powertrain Control Module (PCM), be careful not to damage or distort the connector terminals. Improper measurement technique could result in poor pin to terminal contact.
2. Measure the resistance of the (K21) IAT Signal circuit between the Intake Air Temperature Sensor harness connector and the Powertrain Control Module (PCM) harness connector.
  Is the resistance below 5.0 ohms?
  
  Yes
  - Go to step 4
  No
  - Repair the (K21) IAT Signal circuit for an open circuit or high resistance.
  - Perform the PCM Verification Test. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
(K900) SENSOR GROUND CIRCUIT OPEN OR HIGH RESISTANCE

Fig 3: Checking Ground Circuit
Courtesy of CHRYSLER LLC

NOTE: When checking circuits at the Powertrain Control Module (PCM), be careful not to damage or distort the connector terminals. Improper measurement technique could result in poor pin to terminal contact.
1. Measure the resistance of the (K900) Sensor Ground circuit between the Intake Air Temperature Sensor harness connector and the Powertrain Control Module (PCM) harness connector.
  Is the resistance below 5.0 ohms?
  
  Yes
  - Go to step 5
  No
  - Repair the (K900) Sensor Ground circuit for an open circuit or high resistance.
  - Perform the PCM Verification Test. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
INTAKE AIR TEMPERATURE SENSOR SIGNAL VOLTAGE

Fig 4: Checking IAT Signal Circuit
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Connect the Powertrain Control Module (PCM) connector.
3. Connect a jumper wire between the (K21) IAT Signal circuit and the (K900) Sensor Ground in the Intake Air Temperature Sensor harness connector.
4. Turn the ignition on.
5. With the scan tool, read the Intake Air Temperature Sensor signal voltage.
  Is the voltage below 1.0 volt with the jumper wire in place?
  
  Yes
  - Go to step 6
  No
  - Go to step 7
INTAKE AIR TEMPERATURE SENSOR
1. Turn the ignition off.
2. Inspect the wiring and connectors between the Intake Air Temperature Sensor and the Powertrain Control Module (PCM).
3. Look for any chafed, pierced, pinched, or partially broken wires.
4. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related connectors.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the PCM Verification Test. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Replace the Intake Air Temperature Sensor in accordance with the Service Information.
  - Perform the PCM Verification Test. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Intake Air Temperature Sensor and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
5. Look for the data to change or for the DTC to reset during the wiggle test.
6. Refer to any Technical Service Bulletins that may apply.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the PCM Verification Test. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information.
  - Perform the PCM Verification Test. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .