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 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, with the scan tool, 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 appropriate INTERMITTENT CONDITION diagnostic procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
CHECK THE RADIATOR FAN OPERATION
1. Turn the ignition On.
2. With the scan tool, actuate the cooling fans to 54%.
  Did the cooling fans actuate with the scan tool?
  
  Yes
  - Go To 10
  No
  - Go To 3
CHECK THE RADIATOR FAN FUSE
1. Turn the ignition off.
2. Check the Radiator Fan fuse for an open.
  Is the fuse open (blown)?
  
  Yes
  - Go To 11
  No
  - Go To 4
CHECK THE RADIATOR FAN FUSED B+ CIRCUIT FOR VOLTAGE
1. Reinstall the fuse.
2. Disconnect the Radiator Fan harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (A13) Fused B+ circuit at the Radiator Fan harness connector.
  Does the voltage equal the recorded 12 volt battery voltage?
  
  Yes
  - Go To 5
  No
  - Repair the (A13) Cooling Fan Fused B+ circuit 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 RADIATOR FAN GROUND CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
1. Measure voltage between the (Z824) Ground circuit and the (A13) Cooling Fan Fused B+ circuit at he Radiator Fan harness connector.
  Does the voltage equal the recorded 12 volt battery voltage?
  
  Yes
  - Go To 6
  No
  - Repair the (Z824) Ground circuit 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 PULSE WIDTH MODULATED (PWM) OUTPUT FROM PIM
1. Turn the ignition on.
2. With the scan tool, command the Radiator Fan Duty Cycle to 54%.
3. Measure the duty cycle on the (K175) Radiator Fan Control Signal circuit at the Radiator Fan harness connector. Record the reading.
  Is the duty cycle about 54%?
  
  Yes
  - Replace the Radiator Fan in accordance with the Service Information. Refer to FAN, COOLING, REMOVAL AND INSTALLATION .
  - Perform the Electric Vehicle Control Unit (EVCU) VERIFICATION TEST. Refer to ELECTRIC VEHICLE CONTROL UNIT (EVCU) VERIFICATION TEST .
  No
  - Go To 7
CHECK THE RADIATOR FAN PWM CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the appropriate EVCU harness connector.
3. Measure the resistance of the (K175) Radiator Fan Control Signal circuit between the Radiator Fan harness connector and the EVCU harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 8
  No
  - Repair the (K175) Radiator Fan Control Signal circuit 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 RADIATOR FAN PWM CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition on.
2. Measure the voltage on the (K175) Radiator Fan Control Signal circuit at the EVCU harness connector.
  Is there any voltage present?
  
  Yes
  - Repair the (K175) Radiator Fan Control Signal circuit for a short to voltage.
  - Perform the Electric Vehicle Control Unit (EVCU) VERIFICATION TEST. Refer to ELECTRIC VEHICLE CONTROL UNIT (EVCU) VERIFICATION TEST .
  No
  - Go To 9
CHECK THE RADIATOR FAN PWM CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT
1. Check for continuity between the (K175) Radiator Fan Control Signal circuit and all other circuits at the EVCU harness connector.
  Is there continuity between the (K175) Radiator Fan Control Signal circuit and any other circuit?
  
  Yes
  - Repair the (K175) Radiator Fan Control Signal circuit for a short to another circuit.
  - Perform the Electric Vehicle Control Unit (EVCU) VERIFICATION TEST. Refer to ELECTRIC VEHICLE CONTROL UNIT (EVCU) VERIFICATION TEST .
  No
  - Go To 11
CHECK FUSED B+ CIRCUIT FOR A SHORT TO GROUND
1. Check the (A13) Fused B+ circuit for a short to ground.
  Was a short to ground found on the (A13) Fused B+ circuit?
  
  Yes
  - Repair the (A13) Fused B+ circuit for a short to ground or check for a internally shorted Radiator Fan.
  - Perform the Electric Vehicle Control Unit (EVCU) VERIFICATION TEST. Refer to ELECTRIC VEHICLE CONTROL UNIT (EVCU) VERIFICATION TEST .
  No
  - Inspect the Radiator Fan for obstructions and damage. Repair or replace the Radiator Fan as necessary in accordance with the Service Information. Refer to FAN, COOLING, REMOVAL AND INSTALLATION .
  - Perform the Electric Vehicle Control Unit (EVCU) VERIFICATION TEST. Refer to ELECTRIC VEHICLE CONTROL UNIT (EVCU) VERIFICATION TEST .
CHECK RELATED HARNESS CONNECTIONS
1. Disconnect all EVCU 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 EVCU 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 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 EVCU DTCs.
  Did the DTC return?
  
  Yes
  - Replace the Electric Vehicle Control Unit (EVCU) in accordance with the Service information. Refer to MODULES, HIGH VOLTAGE SYSTEM, REMOVAL AND INSTALLATION .
  - Perform the Electric Vehicle Control Unit (EVCU) VERIFICATION TEST. Refer to ELECTRIC VEHICLE CONTROL UNIT (EVCU) .
  No
  - Perform the Electric Vehicle Control Unit (EVCU) VERIFICATION TEST. Refer to ELECTRIC VEHICLE CONTROL UNIT (EVCU) VERIFICATION TEST .
  - Test complete.