Diagnostic Test

WARNING: This page is about a different car, the 2015 RAM 1500. However, it is still accessible from the selected car via links, so may be relevant.

CHECK FOR AN ACTIVE DTC
NOTE:
Make sure that the engine oil is at the proper level. Also, check the customers oil change history to ensure that the oil is being changed at the correct intervals and that the proper oil viscosity is being used.
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 can result in possible serious or fatal injury.
2. With the scan tool, read DTCs.
  Is the DTC active?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
ENGINE OIL/ENGINE MECHANICAL
NOTE:
The following items must be considered before determining the cause of this DTC. Failure to do so may lead to misdiagnosis.

For the MDS to enable the 4 cylinder mode, the oil pressure has to be approximately 25 psi.

For the MDS to remain enabled in the 4 cylinder mode the engine oil pressure can not drop below 23.2 psi.

When checking the engine oil pressure use a mechanical gauge.
- ENGINE MECHANICAL TOLERANCES OUT OF SPECIFICATION
- ENGINE OIL PRESSURE OUT OF SPECIFICATION
- LOW ENGINE OIL
- DETERIORATED OR DIRTY OIL
- CORRECT VISCOSITY
- ENGINE OIL CONTAMINATED (i.e., coolant and/or fuel)
1. If any of the above conditions are found, repair as necessary.
  Were any of the above conditions present?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 3
ENGINE OIL PRESSURE SENSOR
1. Turn the ignition off.
2. Connect the PCM C2 harness connector.
3. Turn the ignition on.
4. With the scan tool, monitor the Engine Oil Pressure Sensor voltage.
5. Connect a jumper between the (K900) Sensor Ground circuit and the (G6) EOP Signal circuit.
  NOTE:
  Engine Oil Pressure voltage should change from approximately 4.9 volts to less than 0.1 volts.
  
  Is the voltage reading within the listed specification when the jumper is installed?
  
  Yes
  - Verify that there is good pin to terminal contact in the Sensor and Powertrain Control Module connectors. Remove the Engine Oil Pressure sensor and ensure the oil passage/port is free from any blockage. If OK, replace the Engine Oil Pressure Sensor.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 4
    NOTE:
    Remove the jumper before continuing.
CHECK THE (G6) ENGINE OIL PRESSURE SIGNAL CIRCUIT FOR EXCESSIVE RESISTANCE
1. Turn the ignition off.
2. Disconnect the PCM C2 harness connector.
  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.
3. Connect the (special tool #10436, Adapter, GPEC Diagnostic).
4. Measure the resistance of the (G6) EOP Signal circuit from the Engine Oil Pressure Sensor harness connector to the GPEC Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the excessive resistance in the (G6) EOP Signal circuit. Refer to SENSOR, OIL PRESSURE, REMOVAL, 5.7L .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (G6) ENGINE OIL PRESSURE SIGNAL CIRCUIT FOR A SHORT TO GROUND
1. Check for continuity between ground and the (G6) EOP Signal circuit at the Engine Oil Pressure Sensor harness connector.
  Is there continuity between ground and the (G6) EOP Signal circuit?
  
  Yes
  - Repair the (G6) EOP Signal circuit for a short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 6
CHECK THE (F855) 5-VOLT SUPPLY CIRCUIT FOR EXCESSIVE RESISTANCE
1. Measure the resistance of the (F855) 5-Volt Supply circuit from the Engine Oil Pressure Sensor harness connector to the GPEC Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 7
  No
  - Repair the excessive resistance in the (F855) 5-Volt Supply circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (F855) 5-VOLT SUPPLY CIRCUIT FOR A SHORT TO GROUND
1. Check for continuity between ground and the (F855) 5-Volt Supply circuit at the Engine Oil Pressure Sensor harness connector.
  Is there continuity between ground and the (F855) 5-Volt Supply circuit?
  
  Yes
  - Repair the (F855) 5-Volt Supply circuit for a short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 8
CHECK THE (K900) SENSOR GROUND CIRCUIT FOR EXCESSIVE RESISTANCE
1. Measure the resistance of the (K900) Sensor Ground circuit from the Engine Oil Pressure Sensor harness connector to the GPEC Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 9
  No
  - Repair the excessive resistance in the (K900) Sensor Ground circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Engine Oil Pressure 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 Sensor and Powertrain Control Module connectors.
4. Perform any Service Bulletins that may apply.
  Were there 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 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 .