Diagnostic Test

WARNING: This page is about a different car, the 2024 RAM ProMaster EV. However, it is still accessible from the selected car via links, so may be relevant.

CHECK FOR AN ACTIVE DTC
1. With the scan tool, read Body Control Module (BCM) DTCs and record on the repair order.
2. Record the Environmental Data.
3. With the scan tool, erase DTCs.
4. Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
5. With the scan tool, read BCM DTCs.
  Did the DTC return?
  
  Yes
  - Go To Next Step.
  No
  - Perform the TESTING FOR INTERMITTENT CONDITIONS procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
CHECK FOR OTHER DTCS
1. Refer to the recorded DTCs.
  Are there any other BCM LIN DTCs present?
  
  Yes
  - Perform the applicable diagnostic procedure(s).
  No
  - Go To Next Step.
MEASURE THE VOLTAGE ON THE (D402) LIN BUS 2 CIRCUIT AT THE LEFT STEERING WHEEL SWITCH
1. Turn the ignition off.
2. Disconnect the Left Steering Wheel Switch harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (D402) LIN Bus 2 circuit at the Left Steering Wheel Switch harness connector.
  Is there any voltage present?
  
  Yes
  - Go To the appropriate Diagnostic Information .
  No
  - Go To Next Step.
MEASURE THE VOLTAGE ON THE (D402) LIN BUS 2 CIRCUIT AT THE CLOCKSPRING
1. Turn the ignition off.
2. Disconnect the Clockspring harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (D402) LIN Bus 2 circuit at the Clockspring harness connector.
  Is there any voltage present?
  
  Yes
  - Go To the appropriate Diagnostic Information .
  No
  - Go To Next Step.
MEASURE THE VOLTAGE ON THE (D402) LIN BUS 2 CIRCUIT AT THE ELECTRONIC PEDESTRIAN PROTECTION MODULE (EPPM) IF EQUIPPED
NOTE:
If not equipped with an EPPM, Go to Next Step.
1. Turn the ignition off.
2. Disconnect the Electronic Pedestrian Protection Module harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (D402) LIN Bus 2 circuit at the Electronic Pedestrian Protection Module harness connector.
  Is there any voltage present?
  
  Yes
  - Go To the appropriate Diagnostic Information .
  No
  - Go To Next Step.
CHECK THE (D402) LIN BUS 2 CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Check for continuity between ground and the (D402) LIN Bus 2 circuit at the related BCM harness connectors.
  Is there continuity between ground and the (D402) LIN Bus 2 circuit?
  
  Yes
  - Repair the short to ground in the (D402) LIN Bus 2 circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To Next Step.
CHECK THE (D402) LIN Bus 2 CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the Clockspring harness connector.
3. Disconnect the BCM harness connector.
4. Measure the resistance of the (D402) LIN Bus 2 circuit between the Clockspring harness connector and the BCM harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To Next Step.
  No
  - Repair the (D402) LIN Bus 2 circuit for an open or high resistance.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
CHECK RELATED HARNESS CONNECTIONS
1. Disconnect all BCM harness connectors.
2. Disconnect all related in-line harness connections (if equipped).
3. Disconnect the related component harness connectors.
4. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
  - Proper connector installation.
  - Damaged connector locks.
  - Corrosion.
  - Other signs of water intrusion.
  - Weather seal damage (if equipped).
  - Bent terminals.
  - Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
  - Terminals that have been pushed back into the connector cavity.
  - Perform a terminal drag test on each connector terminal to verify proper terminal tension.
  Repair any conditions that are found.
5. Reconnect all BCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. With the scan tool, erase DTCs.
9. Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
10. With the scan tool, read BCM DTCs.
  Did the DTC return?
  
  Yes
  - Replace the Body Control Module (BCM) in accordance with the Service Information. Refer to MODULE, BODY CONTROL (BCM), REMOVAL AND INSTALLATION .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  - Test complete.
LOAD TEST THE POWER SUPPLY AND GROUND CIRCUIT TO THE LEFT STEERING WHEEL SWITCH
Read the CIRCUIT LOAD TESTING PROCEDURE for information on building a simple load test tool, additional load testing information and alternative methods of load testing or voltage drop testing a circuit. Refer to CIRCUIT LOAD TESTING PROCEDURES .
1. Disconnect the Left Steering Wheel Switch harness connector.
2. Connect one lead of the load test tool to the power supply circuit and the other lead of the load test tool to the ground circuit.
3. Ensure that the power supply circuit is being powered on.
4. If there is no resistance in either circuit the bulb on the load test tool should be illuminated and bright. Compare the brightness of the bulb in the load test tool to that of a direct connection to battery.
  NOTE:
  To verify with certainty that the circuit is good, perform a simple voltage drop test across the 3156 bulb of the load test tool. The voltage drop across the bulb should be equal to the voltage reading across the battery terminals if there is no resistance in either circuit.
  
  NOTE:
  A 12-volt test light can be substituted for the load test tool, but only if the test light draws enough current to effectively load test the circuit. Many high impedance test lights draw very little amperage (less than 0.1 amps) and are not reliable to load test a circuit. To perform a proper load test of a circuit, the tool being used should draw more than approximately 0.75 amps.
  
  Is the load test bulb illuminated and bright?
  
  Yes
  - Replace the Left Front Steering Wheel Switch in accordance with the Service Information. Refer to SWITCH, EVIC CONTROL, REMOVAL AND INSTALLATION .
  - .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - If the circuits fail the load test, remove the lead connected to the ground circuit and connect it to a good chassis ground. Check the bulb illumination and voltage drop across the 3156 bulb of the load test tool again. If the bulb is not bright or the voltage drop is still less than battery voltage, repair the battery supply circuit for an open or high resistance. If the bulb is bright or the voltage drop is now equal to battery voltage, repair the ground circuit for an open or high resistance.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
LOAD TEST THE POWER SUPPLY AND GROUND CIRCUIT TO THE CLOCKSPRING
Read the CIRCUIT LOAD TESTING PROCEDURE for information on building a simple load test tool, additional load testing information and alternative methods of load testing or voltage drop testing a circuit. Refer to CIRCUIT LOAD TESTING PROCEDURES .
1. Disconnect the Clockspring harness connector.
2. Connect one lead of the load test tool to the power supply circuit and the other lead of the load test tool to the ground circuit.
3. Ensure that the power supply circuit is being powered on.
4. If there is no resistance in either circuit the bulb on the load test tool should be illuminated and bright. Compare the brightness of the bulb in the load test tool to that of a direct connection to battery.
  NOTE:
  To verify with certainty that the circuit is good, perform a simple voltage drop test across the 3156 bulb of the load test tool. The voltage drop across the bulb should be equal to the voltage reading across the battery terminals if there is no resistance in either circuit.
  
  NOTE:
  A 12-volt test light can be substituted for the load test tool, but only if the test light draws enough current to effectively load test the circuit. Many high impedance test lights draw very little amperage (less than 0.1 amps) and are not reliable to load test a circuit. To perform a proper load test of a circuit, the tool being used should draw more than approximately 0.75 amps.
  
  Is the load test bulb illuminated and bright?
  
  Yes
  - Replace the Clockspring in accordance with the Service Information. Refer to CLOCKSPRING, REMOVAL AND INSTALLATION .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - If the circuits fail the load test, remove the lead connected to the ground circuit and connect it to a good chassis ground. Check the bulb illumination and voltage drop across the 3156 bulb of the load test tool again. If the bulb is not bright or the voltage drop is still less than battery voltage, repair the battery supply circuit for an open or high resistance. If the bulb is bright or the voltage drop is now equal to battery voltage, repair the ground circuit for an open or high resistance.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
LOAD TEST THE POWER SUPPLY AND GROUND CIRCUIT TO THE ELECTRONIC PEDESTRIAN PROTECTION MODULE
Read the CIRCUIT LOAD TESTING PROCEDURE for information on building a simple load test tool, additional load testing information and alternative methods of load testing or voltage drop testing a circuit. Refer to CIRCUIT LOAD TESTING PROCEDURES .
1. Disconnect the Electronic Pedestrian Protection Module harness connector.
2. Connect one lead of the load test tool to the power supply circuit and the other lead of the load test tool to the ground circuit.
3. Ensure that the power supply circuit is being powered on.
4. If there is no resistance in either circuit the bulb on the load test tool should be illuminated and bright. Compare the brightness of the bulb in the load test tool to that of a direct connection to battery.
  NOTE:
  To verify with certainty that the circuit is good, perform a simple voltage drop test across the 3156 bulb of the load test tool. The voltage drop across the bulb should be equal to the voltage reading across the battery terminals if there is no resistance in either circuit.
  
  NOTE:
  A 12-volt test light can be substituted for the load test tool, but only if the test light draws enough current to effectively load test the circuit. Many high impedance test lights draw very little amperage (less than 0.1 amps) and are not reliable to load test a circuit. To perform a proper load test of a circuit, the tool being used should draw more than approximately 0.75 amps.
  
  Is the load test bulb illuminated and bright?
  
  Yes
  - Replace the Electronic Pedestrian Protection Module in accordance with the Service Information. Refer to VEHICLE PEDESTRIAN ALERT (VPA) SPEAKERS .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - If the circuits fail the load test, remove the lead connected to the ground circuit and connect it to a good chassis ground. Check the bulb illumination and voltage drop across the 3156 bulb of the load test tool again. If the bulb is not bright or the voltage drop is still less than battery voltage, repair the battery supply circuit for an open or high resistance. If the bulb is bright or the voltage drop is now equal to battery voltage, repair the ground circuit for an open or high resistance.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .