Diagnostic Test

WARNING: This page is about a different car, the 2015 Fiat 500. However, it is still accessible from the selected car via links, so may be relevant.

ACTIVE DTC
1. Turn the ignition on.
2. With the scan tool, record and erase BPCM DTCs.
3. Turn the ignition off. Wait one minute.
4. Turn the ignition on. Wait one minute.
5. With the scan tool, read DTCs.
  Is the status Active for this DTC?
  
  Yes
  - Go To 2
  No
  - The condition or conditions that originally set this DTC are not present at this time. Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK THE BATTERY PACK CONTROL MODULE (BPCM) BATTERY COOLANT HEATER CONTROL OUTPUT
1. Turn the ignition off.
2. Disconnect the Battery Coolant Heater C1 low voltage harness connector.
3. Turn the ignition on.
4. With the scan tool, actuate the Battery Coolant Heater Duty Cycle in the Electronic Vehicle Control Unit (EVCU) Actuators screen.
5. Using a 12-volt test light connected to a good chassis ground, check the (H378) Battery Coolant Heater Control circuit in the Battery Coolant Heater C1 harness connector.
  Is the test light illuminated and bright?
  
  Yes
  - Go To 3
  No
  - Go To 6
CHECK THE BPCM BATTERY COOLANT HEATER RETURN CIRCUIT
1. With the scan tool, actuate the Battery Coolant Heater Duty Cycle in the Electronic Vehicle Control Unit (EVCU) Actuators screen.
2. Connect a 12-volt test light between the (H378) Battery Coolant Heater Control circuit and the (H374) Battery Coolant Heater Return circuit in the Battery Coolant Heater C1 harness connector.
  Is the test light illuminated and bright?
  
  Yes
  - Go To 4
  No
  - Go To 5
CHECK THE BPCM BATTERY COOLANT HEATER GROUND CIRCUIT
1. Using a 12-volt test light connected to B+, check the (Z910) Battery Coolant Heater Ground circuit in the Battery Coolant Heater C1 harness connector.
  Is the test light illuminated and bright?
  
  Yes
  - Replace the Battery Coolant Heater in accordance with the Service Information. Refer to HEATER, BATTERY COOLANT (BCH), REMOVAL .
  - Perform the BATTERY PACK CONTROL MODULE (BPCM) VERIFICATION TEST. Refer to BPCM VERIFICATION TEST .
  No
  - Repair the (Z910) Battery Coolant Heater Ground circuit for an open or high resistance.
  - Perform the BATTERY PACK CONTROL MODULE (BPCM) VERIFICATION TEST. Refer to BPCM VERIFICATION TEST .
CHECK THE (H374) HEATER COOLANT VALVE RETURN CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the High Voltage Battery Pack C3 low voltage harness connector.
3. Measure the resistance of the (H374) Battery Coolant Heater Return circuit between the Battery Coolant Heater C1 harness connector and the High Voltage Battery Pack C3 low voltage harness connector.
  Is the resistance below 5 Ohms?
  
  Yes
  - Replace the High Voltage Battery Pack in accordance with the Service Information. Refer to BATTERY, HIGH-VOLTAGE, REMOVAL .
  - Perform the BATTERY PACK CONTROL MODULE (BPCM) VERIFICATION TEST. Refer to BPCM VERIFICATION TEST .
  No
  - Repair the (H374) Battery Coolant Heater Return circuit for an open or high resistance
  - Perform the BATTERY PACK CONTROL MODULE (BPCM) VERIFICATION TEST. Refer to BPCM VERIFICATION TEST .
CHECK THE (H378) BATTERY HEATER COOLANT CONTROL CIRCUIT FOR AN OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the High Voltage Battery Pack C3 low voltage harness connector.
3. Measure the resistance of the (H378) Battery Coolant Heater Control circuit between the Battery Coolant Heater C1 harness connector and the High Voltage Battery Pack C3 low voltage harness connector.
  Is the resistance below 5 Ohms?
  
  Yes
  - Replace the High Voltage Battery Pack in accordance with the Service Information. Refer to BATTERY, HIGH-VOLTAGE, REMOVAL .
  - Perform the BATTERY PACK CONTROL MODULE (BPCM) VERIFICATION TEST. Refer to BPCM VERIFICATION TEST .
  No
  - Repair the (H378) Battery Coolant Heater Control circuit for an open or high resistance.
  - Perform the BATTERY PACK CONTROL MODULE (BPCM) VERIFICATION TEST. Refer to BPCM VERIFICATION TEST .