Diagnostic Test

ACTIVE DTC
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.
  
  NOTE: Diagnose and repair any system voltage DTCs before continuing with this test.
2. With the scan tool, select View DTCs.
  Is the DTC active at this time?
  
  Yes
  - Go to step 2
  No
  - Refer to the INTERMITTENT CONDITION Diagnostic Procedure. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
IAT SENSOR
1. Turn the ignition off.
2. Disconnect the IAT sensor harness connector.
3. Ignition on, engine not running.
4. With the scan tool, read IAT voltage.
  NOTE: The sensor voltage should be approximately 5.0 Volts (+/- 0.1 Volts) with the connector disconnected.
  
  Does the scan tool display the voltage as described above?
  
  Yes
  - Verify that there is good pin to terminal contact in the IAT sensor and PCM connectors. Replace the IAT sensor if no problems were found in the connectors.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Go to step 3
(K21) IAT SENSOR SIGNAL SHORTED TO GROUND

Fig 1: Measuring Resistance Between Ground And IAT Signal Circuit In IAT Sensor Electrical Connector
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the C2 PCM harness connector.
3. Measure the resistance between ground and the (K21) IAT signal circuit in the IAT sensor harness connector.
  Is the resistance below 100 Ohms?
  
  Yes
  - Repair the short to ground in the (K21) IAT signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Go to step 4
(K21) IAT SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND CIRCUIT

Fig 2: Measuring Resistance Between IAT Signal Circuit And Sensor Ground Circuit In IAT Sensor Electrical Connector
Courtesy of CHRYSLER LLC
1. 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
  - Repair the short between the (K900) sensor ground circuit and the (K21) IAT signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Go to step 5
EXCESSIVE RESISTANCE IN THE (K21) IAT SIGNAL CIRCUIT

Fig 3: Measuring Resistance Of IAT Signal Circuit Between IAT Sensor Harness Connector And Appropriate Terminal Of Special Tool #8815
Courtesy of CHRYSLER LLC

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 PCM Pinout Box 8815 to perform diagnosis.
1. Measure the resistance of the (K21) IAT signal circuit between the IAT sensor harness connector and the appropriate terminal of special tool #8815.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go to step 6
  No
  - Repair the excessive resistance in the (K21) IAT signal circuit.
  - Perform the POWERTRAIN 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 electrical connectors between the IAT 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. Verify that there is good pin to terminal contact in the IAT sensor and PCM connectors.
4. Refer to any Technical Service Bulletins (TSBs) that may apply.
  Were there any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
  No
  - Replace and program the PCM in accordance with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .