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.

RADIATOR FAN HIGH SPEED RELAY OPERATION
NOTE:
Diagnose and repair any Coolant Fan circuit or Temperature Sensor circuit DTCs before proceeding with this test.
1. Turn the ignition on.
2. With the scan tool, actuate the High Speed Fan Relay.
  Does the Cooling Fan operate?
  
  Yes
  - Go To 2
  No
  - Go To 3
RADIATOR FAN LOW SPEED RELAY OPERATION
1. With the scan tool, actuate the Low Speed Fan Relay.
  Does the Cooling Fan operate?
  
  Yes
  - Test complete.
  No
  - Go To 8
RADIATOR FAN HIGH SPEED RELAY
1. Turn the ignition off.
2. Verify the Radiator Fan High Speed Relay is installed properly and that the terminals are making a tight fit.
3. Remove the Radiator Fan High Speed Relay and substitute it with a known good Relay.
4. Ignition on, engine not running.
5. With a scan tool, actuate the High Speed Fan Relay.
  Is the Cooling Fan operating?
  
  Yes
  - Replace the Radiator Fan High Speed Relay.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to the appropriate Diagnostics & Testing article in Engine Performance. For 16V, refer to POWERTRAIN VERIFICATION TEST, 16V . For 16V Turbo, refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Go To 4
GROUND CIRCUIT OPEN
1. Turn the ignition off.
2. Disconnect the Radiator Cooling Fan Module harness connector.
3. Using a 12-volt test light connected to voltage, check the Ground circuit in the Cooling Fan Module harness connector.
  NOTE:
  The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
  
  Is the test light illuminated and bright?
  
  Yes
  - Go To 5
  No
  - Repair the Ground circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to the appropriate Diagnostics & Testing article in Engine Performance. For 16V, refer to POWERTRAIN VERIFICATION TEST, 16V . For 16V Turbo, refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
RADIATOR COOLING FAN MODULE
1. Turn the ignition on.
2. Using a 12-volt test light connected to ground, check the Radiator Fan Control circuit in the Radiator Cooling Fan Module harness connector.
3. With the scan tool, actuate the High Speed Fan Relay.
  NOTE:
  The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
  
  Is the test light illuminated and bright?
  
  Yes
  - Replace the Cooling Fan.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to the appropriate Diagnostics & Testing article in Engine Performance. For 16V, refer to POWERTRAIN VERIFICATION TEST, 16V . For 16V Turbo, refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Go To 7
FUSED B+ CIRCUIT OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Using a 12 volt test light connected to ground, check the Fused B+ circuits at the High Speed Fan Relay terminals.
  Does the test light illuminate brightly?
  
  Yes
  - Go To 7
  No
  - Repair the Fused B+ circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to the appropriate Diagnostics & Testing article in Engine Performance. For 16V, refer to POWERTRAIN VERIFICATION TEST, 16V . For 16V Turbo, refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
(N24) RAD FAN CONTROL RELAY OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Remove the Radiator Fan High Relay.
3. Turn the ignition on.
4. Using a fuse jumper wire, connect one end of the jumper wire to the Fused B+ circuit and the (N24) Rad Fan Control Relay Output circuit.
5. Using a 12-volt test light connected to voltage, check the (N24) Rad Fan Control Relay Output circuit at the Radiator Cooling Fan harness connector.
  NOTE:
  The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
  
  Is the test light illuminated and bright?
  
  Yes
  - Repair the (N24) Rad Fan Control Relay Output circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to the appropriate Diagnostics & Testing article in Engine Performance. For 16V, refer to POWERTRAIN VERIFICATION TEST, 16V . For 16V Turbo, refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Go To 13
RADIATOR FAN LOW SPEED RELAY
1. Turn the ignition off.
2. Verify the Radiator Fan Low Speed Relay is installed properly and that the terminals are making a tight fit.
3. Remove the Radiator Fan Low Speed Relay and substitute it with a known good Relay.
4. Ignition on, engine not running.
5. With a scan tool, actuate the Low Speed Fan Relay.
  Is the Cooling Fan operating?
  
  Yes
  - Replace the Radiator Fan Low Speed Relay.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to the appropriate Diagnostics & Testing article in Engine Performance. For 16V, refer to POWERTRAIN VERIFICATION TEST, 16V . For 16V Turbo, refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Go To 9
RADIATOR COOLING FAN MODULE
1. Turn the ignition off.
2. Disconnect the Radiator Cooling Fan Module harness connector.
3. Turn the ignition on.
4. Using a 12-volt test light connected to ground, check the (N24) Rad Fan Control Relay Output circuit in the Radiator Cooling Fan Module harness connector.
5. With the scan tool, actuate the Low Speed Fan Relay.
  NOTE:
  The test light should be illuminated but dim.
  
  Is the test light illuminated and bright?
  
  Yes
  - Replace the Cooling Fan.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to the appropriate Diagnostics & Testing article in Engine Performance. For 16V, refer to POWERTRAIN VERIFICATION TEST, 16V . For 16V Turbo, refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Go To 10
RADIATOR FAN CONTROL RELAY OUTPUT
1. Turn the ignition off.
2. Disconnect the Radiator Fan Resistor harness connector.
3. Turn the ignition on.
4. Using a 12-volt test light connected to ground, check the (N23) Rad Fan Low Speed Control Output circuit in the Radiator Fan Resistor harness connector.
5. With the scan tool, actuate the Low Speed Fan Relay.
  NOTE:
  The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
  
  Is the test light illuminated and bright?
  
  Yes
  - Go To 11
  No
  - Go To 12
(N24) RAD FAN CONTROL RELAY OUTPUT OPEN OR HIGH RESISTANCE.
1. Turn the ignition off.
2. Measure the resistance in the (N24) Rad Fan Control Relay Output circuit from the Cooling Fan harness connector to the Radiator Fan Resistor harness connector.
  Is the resistance below 100 Ohms?
  
  Yes
  - Replace the Radiator Fan Resistor in accordance with the Service Information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to the appropriate Diagnostics & Testing article in Engine Performance. For 16V, refer to POWERTRAIN VERIFICATION TEST, 16V . For 16V Turbo, refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Repair the open or high resistance in the (N24) Rad Fan Control Relay Output circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to the appropriate Diagnostics & Testing article in Engine Performance. For 16V, refer to POWERTRAIN VERIFICATION TEST, 16V . For 16V Turbo, refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
(N23) RADIATOR FAN LOW SPEED CONTROL OUTPUT CIRCUIT OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Remove the Low Speed Rad Fan Relay.
3. Turn the ignition on.
4. Using a fuse jumper wire, connect one end of the jumper wire to the Fused B+ circuit and the other end to the (N23) Rad Fan Low Speed Control Relay Output circuit.
5. Using a 12-volt test light connected to voltage, check the (N23) Rad Fan Low Speed Control Relay Output circuit at the Radiator Fan resistor harness connector.
  NOTE:
  The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
  
  Does the test light illuminate brightly?
  
  Yes
  - Go To 13
  No
  - Repair the open or high resistance in the (N23) Radiator Fan Low Speed Control Output circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to the appropriate Diagnostics & Testing article in Engine Performance. For 16V, refer to POWERTRAIN VERIFICATION TEST, 16V . For 16V Turbo, refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Cooling Fan Module, and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Cooling Fan Module and Powertrain Control Module (PCM) connectors.
4. Perform any Technical Service Bulletins (TSBs) that may apply.
  Were there any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to the appropriate Diagnostics & Testing article in Engine Performance. For 16V, refer to POWERTRAIN VERIFICATION TEST, 16V . For 16V Turbo, refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .
  No
  - Replace the Powertrain Control Module (PCM) in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL, REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to the appropriate Diagnostics & Testing article in Engine Performance. For 16V, refer to POWERTRAIN VERIFICATION TEST, 16V . For 16V Turbo, refer to POWERTRAIN VERIFICATION TEST, 16V Turbo .