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.
  
  NOTE: Diagnose and repair any system voltage or sensor supply voltage DTCs before continuing with this test.
2. With the scan tool, select View DTCs.
  Is the status Active for this DTC?
  
  Yes
  - Go to step 2
  No
  - Perform the CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. See DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure .
(C818) A/C PRESSURE SENSOR SUPPLY CIRCUIT SHORTED TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the A/C Pressure Transducer connector.
3. Disconnect the Totally Integrated Power Module (TIPM) harness connector.
4. Turn the ignition on.
5. Measure the voltage of the (C818) A/C Pressure Sensor Supply circuit in the A/C Pressure Transducer harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the (C818) A/C Pressure Sensor Supply circuit for a short to voltage.
  - Perform the Body Verification Test. Refer to DTC-Based Diagnostics/MODULE, Totally Integrated Power (TIPM) - Standard Procedure .
  No
  - Go to step 3
(C18) A/C PRESSURE TRANSDUCER SIGNAL CIRCUIT SHORTED TO VOLTAGE
1. Measure the voltage of the (C18) A/C Pressure Transducer Signal circuit in the A/C Pressure Transducer harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the (C18) A/C Pressure Transducer Signal circuit for a short to voltage.
  - Perform the Body Verification Test. Refer to DTC-Based Diagnostics/MODULE, Totally Integrated Power (TIPM) - Standard Procedure .
  No
  - Go to step 4
(C18) A/C PRESSURE TRANSDUCER SIGNAL CIRCUIT SHORTED TO THE (C818) A/C PRESSURE SENSOR SUPPLY CIRCUIT
1. Measure the resistance between the (C18) A/C Pressure Transducer Signal circuit and the (C818) A/C Pressure Sensor Supply in the A/C Pressure Transducer harness connector.
  Is the resistance below 100 ohms?
  
  Yes
  - Repair the (C18) A/C Pressure Transducer Signal circuit for a short to the (C818) A/C Pressure Sensor Supply circuit.
  - Perform the Body Verification Test. Refer to DTC-Based Diagnostics/MODULE, Totally Integrated Power (TIPM) - Standard Procedure .
  No
  - Go to step 5
(C18) A/C PRESSURE TRANSDUCER SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Measure the resistance of the (C18) A/C Pressure Transducer Signal between the A/C Pressure Transducer harness connector and the TIPM harness connector.
  Is the resistance below 5.0 ohms?
  
  Yes
  - Go to step 6
  No
  - Repair the (C18) A/C Pressure Transducer Signal for an open circuit or high resistance.
  - Perform the Body Verification Test. Refer to DTC-Based Diagnostics/MODULE, Totally Integrated Power (TIPM) - Standard Procedure .
(C918) SENSOR GROUND CIRCUIT OPEN OR HIGH RESISTANCE
1. Measure the resistance of the (C918) Sensor Ground circuit between the A/C Pressure Transducer harness connector and the TIPM harness connector.
  Is the resistance below 5.0 ohms?
  
  Yes
  - Go to step 7
  No
  - Repair the (C918) Sensor Ground circuit for an open circuit or high resistance.
  - Perform the Body Verification Test. Refer to DTC-Based Diagnostics/MODULE, Totally Integrated Power (TIPM) - Standard Procedure .
A/C PRESSURE TRANSDUCER
1. Turn the ignition off.
2. Connect the TIPM harness connector.
3. Connect a jumper wire between the (C918) Sensor Ground circuit and the (C18) A/C Pressure Transducer Signal circuit in the A/C Pressure Transducer harness connector.
4. Turn the ignition on.
5. With the scan tool, read the A/C Pressure Transducer signal voltage.
  NOTE: The sensor voltage should be approximately 0.0 volts (plus or minus.1 volt) with the jumper wire in place.
  
  Does the scan tool display the voltage as described above?
  
  Yes
  - Replace the A/C Pressure Transducer in accordance with the Service Information.
  - Perform the Body Verification Test. Refer to DTC-Based Diagnostics/MODULE, Totally Integrated Power (TIPM) - Standard Procedure .
  No
  - Go to step 8
TOTALLY INTEGRATED POWER MODULE (TIPM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the A/C Pressure Transducer and the Totally Integrated Power (TIPM).
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 Body Verification Test. Refer to DTC-Based Diagnostics/MODULE, Totally Integrated Power (TIPM) - Standard Procedure .
  No
  - Replace and program the Totally Integrated Power (TIPM) in accordance with the Service Information.
  - Perform the Body Verification Test. Refer to DTC-Based Diagnostics/MODULE, Totally Integrated Power (TIPM) - Standard Procedure .