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
WARNING:
On vehicles equipped with the high voltage system, you must thoroughly read and follow all High Voltage Safety procedures. In addition, before performing any diagnostic or service procedure near a high voltage component, you must perform the High Voltage Power Down. Failure to follow these instructions may result in possible serious or fatal injury.

Read the HIGH-VOLTAGE SAFETY PROCEDURES. Refer to HIGH VOLTAGE SAFETY PROCEDURES .

When the HIGH-VOLTAGE POWER-DOWN PROCEDURE is necessary. Refer to VEHICLE HIGH VOLTAGE POWER DOWN .
1. With the scan tool, read DTCs in all Electronic Control Units (ECUs) and record on the repair order.
2. For future reference, run and save a vehicle Scan Report and all related recorded data.
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 When Monitored and Set Conditions above and recorded data, operate the vehicle in the conditions that set the DTC.
7. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
CHECK THE S/C SIGNAL CIRCUITS FOR A SHORT TO VOLTAGE
WARNING:
Turn the ignition off disconnect the 12-volt battery and wait two minutes before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.

WARNING:
Do not place an intact non-deployed airbag face down on a hard surface, the airbag propels into the air if accidentally deployed. Failure to follow these instructions may result in possible serious or fatal injury.
1. Turn the ignition off.
2. Disconnect the Steering Column Control Module (SCCM) C2 harness connector.
3. Turn the ignition on.
4. Measure the voltage on the:
  - S/C (V71) Signal 1 circuit in the SCCM harness connector.
  - S/C (V72) On/Off Signal circuit in the SCCM harness connector.
  Is the voltage above 5.6 volts for either circuit?
  
  Yes
  - Repair the circuit that measured above 5.6 volts short to voltage.
  - Perform the Electric Vehicle Control Unit (EVCU) VERIFICATION TEST. Refer to ELECTRIC VEHICLE CONTROL UNIT (EVCU) VERIFICATION TEST .
  No
  - Go To 3
CHECK THE S/C SWITCH CIRCUITS FOR A SHORT TO GROUND
1. Disconnect the BCM C8 harness connector.
2. Check for continuity between ground and the:
  - S/C (V71) Signal 1 circuit at the SCCM C2 harness connector.
  - S/C (V72) On/Off Signal circuit at the SCCM C2 harness connector.
  Does either circuit have continuity to ground?
  
  Yes
  - Repair the S/C circuit that showed continuity to ground.
  - Perform the Electric Vehicle Control Unit (EVCU) VERIFICATION TEST. Refer to ELECTRIC VEHICLE CONTROL UNIT (EVCU) VERIFICATION TEST .
  No
  - Go To 4
CHECK THE S/C SWITCH CIRCUITS FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the:
  - S/C (V71) Signal 1 circuit between the SCCM C2 harness connector and the BCM C8 harness connector.
  - S/C (V72) On/Off Signal circuit between the SCCM C2 harness connector and the BCM C8 harness connector.
  - S/C Switch Return circuit between the SCCM C2 harness connector and the BCM C8 harness connector.
  Is the resistance below 3.0 Ohms for both circuits?
  
  Yes
  - Go To 5
  No
  - Repair the S/C circuit that measured above 3.0 Ohms for an open or high resistance.
  - Perform the Electric Vehicle Control Unit (EVCU) VERIFICATION TEST. Refer to ELECTRIC VEHICLE CONTROL UNIT (EVCU) VERIFICATION TEST .
CHECK THE ABILITY OF THE BCM TO DETECT THE SPEED CONTROL SWITCH
1. Reconnect all disconnected harness connectors.
2. With the scan tool, monitor the Speed Control Switch voltage signal.
  NOTE:
  If the reading is not available on the scan tool, back probe and measure the voltage on the S/C (V71) On/Off Signal circuit at the SCCM harness connector.
3. Cycle the Speed Control On/Off Switch to between on and off.
  NOTE:
  If the reading is not available on the scan tool, back probe and measure the voltage on the S/C (V72) Signal 1 circuit at the SCCM harness connector.
4. Press the other Speed Control functions.
  NOTE:
  The S/C Signal On/Off MUX voltage should change when the speed control functions are selected. The On/Off MUX voltage signal should not equal 0 volts or 5.0 volts at any time.
  
  NOTE:
  The S/C Signal 1 is open when no functions are selected. The voltage should read 5.0 volts with no functions selected. When a speed control function is selected the voltage should change and be between 0 volts and 5.0 volts.
  
  Are the Speed Control Switch voltage signals changing as described above?
  
  Yes
  - Go To 6
  No
  - Replace the Steering Column Control Module Assembly in accordance with the Service Information.
  - Perform the Electric Vehicle Control Unit (EVCU) VERIFICATION TEST. Refer to ELECTRIC VEHICLE CONTROL UNIT (EVCU) VERIFICATION TEST .
REPLACE THE SPEED CONTROL SWITCH AND RETEST FOR DTC
1. Turn the ignition off.
2. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Speed Control Switch and the Body Control Module.
3. Replace the Speed Control Switch in accordance with the Service information.
4. Reconnect all electrical connections.
5. Turn the ignition on.
6. With the scan tool, navigate to BCM data and monitor all Speed Control Switch data. Operate all Speed Control switch functions.
  Does the Speed Control Switch data display correctly?
  
  Yes
  - Replacing the Speed Control Switch repaired the fault.
  - Perform the Electric Vehicle Control Unit (EVCU) VERIFICATION TEST. Refer to ELECTRIC VEHICLE CONTROL UNIT (EVCU) VERIFICATION TEST .
  No
  - Go To 7
CHECK RELATED BCM AND COMPONENT 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.
  - Check for spread terminals and 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. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
10. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Replace and program the Body Control Module (BCM) in accordance with the Service Information. Refer to BODY CONTROL MODULE (BCM) .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - The wiring or poor connection problem has been repaired.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .