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.

READ AND RECORD DTCS AND ENVIRONMENTAL DATA - ERASE DTCS AND CHECK FOR THE DTC TO RETURN
1. With the scan tool, read DTCs in all Electronic Control Units (ECUs) and record on the repair order.
2. With the scan tool, run a vehicle Scan Report, or record the Environmental Data related to the DTCs.
3. With the scan tool, erase all DTCs.
4. Turn the ignition off for a minimum of 10.0 seconds.
5. Turn the ignition on.
6. Using the recorded Environmental Data and the When Monitored Conditions above, operate the vehicle in the conditions that set the DTC.
7. With the scan tool, read Body Control Module (BCM) DTCs.
  Did the DTC return?
  
  Yes
  - Go To Next Step.
  No
  - Perform the appropriate INTERMITTENT CONDITION diagnostic procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
DISCONNECT THE RELATED BODY CONTROL MODULE (BCM) HARNESS CONNECTOR AND CHECK THE (W9) ELECTRIC WINDSHIELD DE-ICER CONTROL CIRCUIT FOR A SHORT TO VOLTAGE
NOTE:
Make sure the Windshield Wiper De-icer output is not active when performing this step.
1. Turn the ignition off.
2. Disconnect the related BCM harness connector for the circuit being tested. Note: Use the wiring diagram as a guide to follow the path of the circuit.
3. Turn the ignition on.
4. Using a DVOM, measure the voltage on the circuit being tested at the related BCM harness connector.
  NOTE:
  When probing a circuit at any harness connector, always use an appropriate probing tool to prevent any possible damage to the harness connector terminals.
  
  Is there any voltage present?
  
  Yes
  - Repair the short to voltage on the Electric Windshield De-Icer Control circuit.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To Next Step.
DISCONNECT THE BCM HARNESS CONNECTOR(S) AND CHECK THE (W9) ELECTRIC WINDSHIELD DE-ICER CONTROL CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
1. The ignition must be off when checking the resistance of a circuit.
2. Disconnect all Electronic Control Unit (ECU) harness connectors containing the circuit being tested. Note: Use the wiring diagram as a guide to follow the path of the circuit.
3. Before measuring the resistance of any circuit, first measure the resistance between the two leads of the DVOM. Note: The meter leads can add resistance to the measurement value.
4. Connect one lead of the DVOM to the circuit being tested at the PDC Assembly harness connector.
5. Connect the other lead to the circuit being tested at the Electronic Control Unit (ECU) harness connector and measure the resistance of the circuit.
  NOTE:
  When probing a circuit at any harness connector, always use an appropriate probing tool to prevent any possible damage to the harness connector terminals.
  
  Is the resistance above 3.0 Ohms?
  
  Yes
  - Repair the circuit for an open or high resistance.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To Next Step.

LOAD TEST THE (Z909) WINDSHIELD DE-ICER RELAYS GROUND CIRCUIT

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 .

Disconnect the Windshield De-Icer relay harness connector to isolate the ground circuit.

Connect the positive lead of the load test tool to the positive side of the Battery and connect the negative lead of the load test tool to the ground circuit at the left taillight harness connector (A).

Courtesy of CHRYSLER GROUP, LLC

The bulb on the load test tool should be illuminated and bright if there is no resistance in either circuit. 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.

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
- Go To Next Step.
No
- Repair the ground circuit for an open or high resistance.
- Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .

CHECK THE BCM ELECTRIC WINDSHIELD DE-ICER CONTROL OUTPUT
1. Turn the ignition on.
2. Connect a 12-volt test light between ground and the (W9) Electric Windshield De-Icer Control circuit at the Windshield De-Icer Relay harness connector.
3. Turn the Windshield De-icer on.
  NOTE:
  The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.
  
  Does the test light illuminate brightly with the Windshield De-Icer on?
  
  Yes
  - Replace the Windshield De-Icer Relays in accordance with the Service Information.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To Next Step.
DISCONNECT RELATED BCM HARNESS CONNECTIONS AND INSPECT FOR PROBLEMS
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. Connect all BCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Connect 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.