Diagnostic Test

WARNING: This page is about a different car, the 2015 RAM 3500 HD and 2015 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.

ACTIVE DTC
NOTE:
Diagnose and repair any system voltage or sensor reference voltage DTCs before continuing with this test.

NOTE:
Make sure the A/C refrigerant System is properly charged in accordance with the service information. Refer to SPECIFICATIONS .
1. Start the engine and allow it to idle.
  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 can result in possible serious or fatal injury.
2. Turn the A/C on.
3. With the scan tool, select View DTCs.
  Is the DTC Active at this time?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK THE (F855) 5-VOLT SUPPLY CIRCUIT
1. Turn the ignition off.
2. Disconnect the A/C Pressure Transducer harness connector.
3. Turn the ignition on.
4. Measure the voltage of the (K854) 5-Volt Supply circuit in the A/C Pressure Transducer harness connector.
  Is the voltage reading between 4.8 and 5.2 volts?
  
  Yes
  - Go To 3
  No, voltage is too high
  - Repair the (K854) 5-Volt Supply circuit for a short to voltage.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No, voltage is too low
  - Repair the (K854) 5-Volt Supply circuit for an open or short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (C18) A/C PRESSURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO VOLTAGE
1. Measure the voltage of the (C18) A/C Pressure Sensor Signal circuit in the A/C Pressure Transducer harness connector.
  Is the voltage reading above 5.2 volts?
  
  Yes
  - Repair the (C18) A/C Pressure Sensor Signal circuit for a short to voltage.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 4
CHECK FOR THE (C18) A/C PRESSURE SENSOR SIGNAL CIRCUIT SHORTED TO THE (K854) 5-VOLT SUPPLY CIRCUIT
1. Turn the ignition off.
2. Disconnect the PCM C2 harness connector.
3. Measure the resistance between the (C18) A/C Pressure Sensor Signal circuit and the (K854) 5-Volt Supply circuit in the A/C Pressure Transducer harness connector.
  Is the resistance above 10k Ohms?
  
  Yes
  - Go To 3
  No
  - Repair the (C18) A/C Pressure Sensor Signal circuit for a short to the (K854) 5-Volt Supply circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (C18) A/C PRESSURE SENSOR SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
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 the GPEC Diagnostic Adaptor to perform the diagnosis.
1. Connect the (special tool #10436, Adapter, GPEC Diagnostic).
2. Measure the resistance of the (C18) A/C Pressure Sensor Signal circuit between the A/C Pressure Transducer harness connector and the GPEC Adaptor.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 6
  No
  - Repair the (C18) A/C Pressure Sensor Signal circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (K900) SENSOR GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the (K900) Sensor Ground circuit between the A/C Pressure Transducer harness connector and the GPEC Adaptor.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go To 7
  No
  - Repair the (K900) Sensor Ground circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
A/C PRESSURE TRANSDUCER
1. Turn the ignition off.
2. Reconnect the PCM harness connectors.
3. Connect a jumper between the (K900) Sensor Ground circuit and the (C18) A/C Pressure Sensor Signal circuit at the A/C Pressure Transducer harness connector.
4. Turn the ignition on.
5. With the scan tool, view DTCs.
  Is the P0532-A/C PRESSURE SENSOR CIRCUIT LOW DTC as active or pending with the jumper in place?
  
  Yes
  - Replace the A/C Pressure Transducer in accordance with the service information. Refer to TRANSDUCER, A/C PRESSURE, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 8
POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the A/C Pressure Transducer 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. Perform any Technical Service Bulletins that may apply.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Replace and program the Powertrain Control Module (PCM) in accordance with the service information. Refer to MODULE, POWERTRAIN CONTROL, REMOVAL . Refer to PCM/ECM REPROGRAMMING - GAS .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .