Diagnostic Test

WARNING: This page is about a different car, the 2006 Dodge Magnum, 2006 Dodge Charger, and 2006 Chrysler 300. However, it is still accessible from the selected car via links, so may be relevant.

1) A/C PRESSURE TRANSDUCER VOLTAGE ABOVE 4.9 VOLTS
NOTE: Make sure the A/C refrigerant system is properly charged per Service Information.

Start the engine.

With a scan tool, read the A/C Pressure Sensor voltage.

Is the voltage above 4.9 volts?

Yes
1. Go To 2).
No
1. Refer to INTERMITTENT CONDITION .
2. Perform POWERTRAIN VERIFICATION TEST .
2) A/C PRESSURE TRANSDUCER

Fig 1: Checking A/C Pressure Transducer Signal Circuit & Ground Circuit
Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition off.

Disconnect the A/C Pressure Transducer harness connector.

Connect a jumper wire between the (C18) A/C Pressure Signal circuit and the (C918) Sensor Ground circuit in the Transducer harness connector.

Ignition on, engine not running.

With the scan tool, monitor the A/C Pressure Transducer voltage.

Is the voltage below 1.0 volt with the jumper wire installed?

Yes
1. Replace the A/C Pressure Transducer.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Go To 3).
  NOTE: Remove the jumper wire before continuing.
3) (C18) A/C PRESSURE SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE

Fig 2: Checking A/C Pressure Transducer Signal Circuit
Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition off.

Disconnect the C1 FCM harness connector.

Ignition on, engine not running.

Measure the voltage on the (C18) A/C Pressure Signal circuit in the A/C Pressure Transducer harness connector.

Is there voltage present?

Yes
1. Repair the short to battery voltage in the (C18) A/C Pressure Signal circuit.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Go To 4).
4) (C18) A/C PRESSURE SIGNAL CIRCUIT OPEN

Fig 3: Checking A/C Pressure Transducer Signal Circuit
Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition off.

Measure the resistance of the (C18) A/C Pressure Signal circuit from the A/C Pressure Transducer harness connector to the C1 FCM harness connector.

Is the resistance below 5.0 ohms?

Yes
1. Go To 5).
No
1. Repair the open in the (C18) A/C Pressure Signal circuit.
2. Perform POWERTRAIN VERIFICATION TEST .
5) (C18) A/C PRESSURE SIGNAL CIRCUIT SHORTED TO THE (F891) 5-VOLT SUPPLY CIRCUIT

Fig 4: Checking A/C Pressure Transducer Signal Circuit & 5-Volt Supply Circuit
Courtesy of DAIMLERCHRYSLER CORP.

Measure the resistance between the (C18) A/C Pressure Signal circuit and the (F891) 5-volt Supply circuit in the A/C Pressure Transducer harness connector.

Is the resistance below 5.0 ohms?

Yes
1. Repair the short between the (F891) 5-volt Supply circuit and the (C18) A/C Pressure Signal circuit.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Go To 6).
6) (C918) SENSOR GROUND CIRCUIT OPEN

Fig 5: Checking A/C Pressure Transducer Ground Circuit
Courtesy of DAIMLERCHRYSLER CORP.

Disconnect the C3 FCM harness connector.

Measure the resistance of the (C918) Sensor Ground circuit from the A/C Pressure Sensor harness connector to the C3 FCM harness connector.

Is the resistance below 5.0 ohms?

Yes
1. Go To 7).
No
1. Repair the open in the (C918) Sensor Ground circuit
2. Perform POWERTRAIN VERIFICATION TEST .
7) FRONT CONTROL MODULE
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 BODY VERIFICATION TEST - VER 1 .
No
1. Replace and program the Powertrain Control Module per Service Information.
2. Perform BODY VERIFICATION TEST - VER 1 .