Diagnostic Procedure

WARNING: This page is about a different car, the 2004 Dodge Pickup and 2004 Dodge Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Refer to VERIFICATION TESTS for appropriate verification test procedures.

NOTE: Ensure the A/C refrigerant System is properly charged per the Service Information.

Start the engine.
With the DRBIII®, read the A/C Pressure Sensor voltage.

Is the voltage below 0.6 of a volt?
1. Yes --> Go To 2
2. No --> Refer to the SYMPTOM: INTERMITTENT CONDITION Symptom (Diagnostic Procedure).
  Perform (NGC) POWERTRAIN VERIFICATION TEST VER - 2 .
Turn the ignition off.
Disconnect the A/C Pressure Sensor harness connector.

Ignition on, engine not running.

Measure the voltage on the (F855) 5-volt Supply circuit in the A/C Pressure Sensor harness connector.

Is the voltage between 4.5 to 5.2 volts?
1. Yes --> Go To 3
2. No --> Go To 6
With the DRBIII®, monitor the A/C Pressure Sensor voltage.
Is the voltage above 0.6 of a volt?
1. Yes --> Replace the A/C Pressure Sensor.
  Perform (NGC) POWERTRAIN VERIFICATION TEST VER - 2 .
2. No --> Go To 4
Turn the ignition off.
Disconnect the PCM harness connectors.

Measure the resistance between ground and the (C918) A/C Pressure Signal circuit at the A/C Pressure Sensor harness connector.

Is the resistance below 100 ohms?
1. Yes --> Repair the short to ground in the (C918) A/C Pressure Signal circuit.
  Perform (NGC) POWERTRAIN VERIFICATION TEST VER - 2 .
2. No --> Go To 5
Measure the resistance between the (G918) A/C Pressure Signal circuit and the (K900) Sensor ground circuit at the A/C Pressure Sensor harness connector.
Is the resistance below 100 ohms?
1. Yes --> Repair the short between the (K900) Sensor ground circuit and the (C918) A/C Pressure Signal circuit.
  Perform (NGC) POWERTRAIN VERIFICATION TEST VER - 2 .
2. No --> Go To 8
Turn the ignition off.
Disconnect the PCM harness connectors.

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 MILLER SPECIAL TOOL #8815 TO PERFORM DIAGNOSIS.

Measure the resistance of the (F855) 5-volt Supply circuit from the A/C Pressure Sensor harness connector to the appropriate terminal of special tool #8815.

Is the resistance below 5.0 ohms?
1. Yes --> Go To 7
2. No --> Repair the open in the (F855) 5-volt Supply circuit.
  Perform (NGC) POWERTRAIN VERIFICATION TEST VER - 2 .
Measure the resistance between ground and the (F855) 5-volt Supply circuit in the A/C Pressure Sensor harness connector.
Is the resistance below 100 ohms?
1. Yes --> Repair the short to ground in the (F855) 5-volt Supply circuit.
  Perform (NGC) POWERTRAIN VERIFICATION TEST VER - 2 .
2. No --> Go To 8

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.
If there are no possible causes remaining, view repair.
1. Repair
  1. Replace and program the Powertrain Control Module per Service Information.
  2. Perform (NGC) POWERTRAIN VERIFICATION TEST VER - 2 .