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:
Inspect the vehicle for aftermarket accessories that may exceed the Alternator System output.

NOTE:
Inspect and test the Battery with the Midtronics Battery Tester or equivalent for a shorted or dead cell before continuing with this test.

NOTE:
This DTC does not necessarily indicate an overcharging condition. It merely indicates that the Alternator Sense is greater than the Alternator output back to the Battery and PDC.
1. Start the engine.
2. Allow the idle to stabilize.
3. With the scan tool, read the active DTCs.
  Is the DTC active?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK THE ALTERNATOR OUTPUT
1. With the scan tool, navigate to data display and monitor the target charging voltage.
2. Using a voltmeter, measure the voltage at the Alternator output stud.
  NOTE:
  The voltage reading at the Alternator output stud should be within 0.2 volts of the target charging voltage.
  
  Are the voltage readings within 0.2 volts of each other?
  
  Yes
  - Go To 3
  No
  - Replace the Alternator in accordance with the Service Information. Refer to GENERATOR, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE ALTERNATOR OUTPUT CIRCUIT AND SYSTEM VOLTAGE
1. Using a voltmeter, measure the voltage at the Fused B+ circuit at the PDC B+ terminal.
  NOTE:
  Compare the voltage reading to the voltage at the Alternator output stud.
  
  Is the voltage within 0.2 volts of the measurement at the Alternator output stud?
  
  Yes
  - Go To 4
  No
  - Repair the open or excessive resistance in the Alternator output circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE PDC
1. Turn the ignition off.
2. Back probe the (A209) Fused B+ circuit at the PDC C3 harness connector.
3. Start the engine and allow it to idle.
4. Using a voltmeter, measure the voltage at the (A209) Fused B+ circuit.
  NOTE:
  Compare the voltage reading to the voltage at the Alternator output stud.
  
  Is the voltage within 0.2 volts of the measurement at the Alternator output stud?
  
  Yes
  - Go To 5
  No
  - Check the fuse and terminals for signs of a spread terminal, corrosion or high resistance. If OK, replace the PDC in accordance with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (A209) FUSED B+ CIRCUIT VOLTAGE
1. Turn the ignition off.
2. Disconnect the PCM C1 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) in line with the GPEC Adaptor.
4. Turn the ignition on.
5. Using a voltmeter, measure the voltage at the (A209) Fused B+ circuit at the GPEC Adaptor.
  NOTE:
  Compare the voltage reading to the voltage at the Alternator output stud. Approximately 2.0 Ohms of resistance in this circuit can drop the voltage by approximately 0.5 volts.
  
  Is the voltage within 0.2 volts of the measurement at the Alternator output stud?
  
  Yes
  - Go To 6
  No
  - Repair the (A209) Fused B+ circuit for high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
POWERTRAIN CONTROL MODULE (PCM)
1. Perform the NO RESPONSE FROM THE POWERTRAIN CONTROL MODULE test procedure. Refer to DIAGNOSIS AND TESTING .
2. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Alternator and the Powertrain Control Module (PCM).
3. Look for any chafed, pierced, pinched, or partially broken wires.
4. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Alternator and the Powertrain Control Module connectors.
5. 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
  - If the PCM powers and grounds test good, 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 .