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.

CHECK FOR AN ACTIVE DTC
NOTE:
Diagnose and repair any system voltage or sensor supply voltage DTCs before continuing with this test.
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 fitting clothing. Failure to follow these instructions can result in personal or fatal injury.
2. With the scan tool, read DTCs.
  Is the DTC active?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT DTC diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK THE (K157) MAF SIGNAL CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the Mass Air Flow Sensor harness connector.
3. Disconnect the PCM C2 harness connector.
4. Check for continuity between ground and the (K157) MAF Signal circuit in the Mass Air Flow Sensor harness connector.
  Is there continuity between ground and the (K157) MAF Signal circuit?
  
  Yes
  - Repair the (K157) MAF Signal circuit for a short to ground.
  - Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 3
  - Repair the (K157) MAF Signal circuit for a short to ground.
  - Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK FOR THE (K157) MAF SIGNAL CIRCUIT SHORTED TO (K900) SENSOR GROUND CIRCUIT
1. Check for continuity between the (K157) MAF Signal circuit and the (K900) Sensor Ground circuit in the Mass Air Flow Sensor harness connector.
  Is there continuity between the (K157) MAF Signal circuit and the (K900) Sensor Ground circuit in the Mass Air Flow Sensor harness connector?
  
  Yes
  - Repair the (K157) MAF Signal circuit for a short to the (K900) Sensor Ground circuit.
  - Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 4
CHECK THE (K157) MAF 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 (K157) MAF Signal circuit between the Mass Air Flow Sensor harness connector and the GPEC Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the (K157) MAF Signal circuit for an open or high resistance.
  - Perform the PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
MASS AIR FLOW SENSOR
1. Reconnect the PCM C2 harness connector.
2. Replace the Mass Air Flow Sensor in accordance with the Service Information.
3. Start the engine and allow it to reach 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 fitting clothing. Failure to follow these instructions can result in personal or fatal injury.
  
  NOTE:
  Review Freeze Frame information. Operate the vehicle under conditions similar to which the DTC was set.
4. With a scan tool, read DTCs.
  Is the DTC active?
  
  Yes
  - Go To 6
  No
  - Test Complete.
  - Perform the PCM 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 Mass Air Flow Sensor and the Powertrain Control Module (PCM).
2. Perform any Service Bulletins that may apply.
3. Look for any chafed, pierced, pinched, or partially broken wires.
4. Look for broken, bent, pushed out or corroded terminals.
5. Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
6. Look for the data to change or for a DTC to set during the wiggle test.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the PCM 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 PCM VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .