Cooling Fan Inoperative 2.0L
Diagnostic Instructions
Circuit/System Description
The powertrain control module (PCM) commands the fans ON in high speed or low speed. In low speed, the fans are configured in series. In high speed, the fans are configured in parallel.
In low speed operation, the PCM applies ground to the coil side of the low speed relay, which is relay 1. Voltage is applied directly to the left cooling fan through the switch side of the low speed relay. The right fan is connected in series to
the left fan through the de-energized series/parallel relay so that both fans operate at low speed.
In high speed operation, the PCM applies a ground to the coil side of the low speed relay, the series/parallel relay, and the high speed relay, which is relay 2. Voltage is applied directly to the right cooling fan through the switch side of the
high speed relay. The left cooling fan obtains voltage through the low speed relay and ground through the series/parallel relay.
When the PCM is commanding a fan relay ON, the voltage of the control circuit should be low, near 0 volts. When the PCM is commanding a fan relay OFF, the voltage of the control circuit should be high, near battery voltage. If the PCM detects that the
actual voltage of the relay control circuit is different than the expected voltage, DTC P0480 or P0481 will set and the affected PCM driver will be disabled.
Reference Information
Schematic Reference
Engine Cooling Schematics
Connector End View Reference
Description and Operation
Cooling Fan Description and Operation
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Circuit/System Verification
- If DTCs P0480 or P0481 are set, perform those diagnostics first.
- Ignition ON, disconnect the engine coolant temperature (ECT) sensor connector. The fans should activate on high speed.
- Connect the ECT sensor connector. Clear DTCs with a scan tool.
- Verify that the engine coolant temperature is below approximately 93°C (200°F).
- Idle the engine until the coolant reaches fan activation temperature of approximately 93°C (200°F). The fans should activate on low speed.
Circuit/System Testing
Important: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.
- Ignition OFF, disconnect the series/parallel relay.
- Ignition ON, disconnect the ECT sensor connector. The left cooling fan should not activate.
| ⇒ | If the fan is activated, test the left fan ground circuit for a short to ground. |
- Ignition OFF, disconnect the remaining relays.
- Ignition OFF, install a 30A fused jumper between the normally open switch contact terminals at the series/parallel relay connector in order to complete the fan ground circuit. Leave the jumper in place for the remainder of this procedure.
- Ignition OFF, one at a time, connect a 30A fused jumper between the positive terminal at the battery and the fan voltage supply circuit terminal at the cool/fan 1 and the cool/fan 2 relay connectors, and verify fan activation.
| ⇒ | If the appropriate fan does not activate, test the fan voltage supply circuit for a short to ground or open/high resistance. If the circuit tests normal, test the fan ground circuit for an open/high resistance. If the circuits test normal,
replace the fan. |
- Ignition ON, connect a 30A fused jumper between the relay switch voltage supply circuit terminal and the fan voltage supply circuit terminal at the cool/fan 1 relay and the cool/fan 2 relay connections and verify fan activation.
| ⇒ | If the fan does not activate, test the relay switch voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and its fuse is open, test all connected components and replace as necessary. |
- If the circuits and fans test normal, replace the relay.
Repair Instructions
Repair Verification
Ignition ON, command each relay ON and OFF with a scan tool. Observe to verify that the fans turn ON and OFF with each command.
Cooling Fan Inoperative 2.2L
Diagnostic Instructions
Circuit/System Description
The engine cooling fan system consists of one cooling fan and one relay. The relay is powered by the battery positive voltage circuit and controlled by a switched ground from the engine control module (ECM).
During operation, the ECM supplies the ground path for the cooling fan relay through the cooling fan relay control circuit. This energizes the cooling fan relay coil, closes the relay contacts, and supplies battery positive voltage from the cooling fan
fuse through the cooling fan motor supply voltage circuit to the cooling fan. The cooling fan motor is grounded through its own ground circuit.
Reference Information
Schematic Reference
Engine Cooling Schematics
Connector End View Reference
Description and Operation
Cooling Fan Description and Operation
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Circuit/System Verification
- If DTC P0480 is set, then perform that diagnostic first.
- Ignition ON, command the relay ON and OFF with a scan tool. Observe to verify that the fan turns ON and OFF with each command.
Circuit/System Testing
- Ignition OFF, disconnect the relay.
- Connect a 30A fused jumper between the positive terminal at the battery and the fan voltage supply circuit terminal X1 at the relay connection and verify fan activation.
| ⇒ | If the fan does not activate, test the fan voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal, test the fan ground circuit for an open/high resistance. If the fan did not activate and the
circuits test normal, replace the fan. |
- Ignition ON, connect a 30A fused jumper between the relay switch voltage supply circuit terminal Y3 and the fan voltage supply circuit terminal X1 at the relay connection and verify fan activation.
| ⇒ | If the fan does not activate, test the relay switch voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and its fuse is open, test all connected components and replace as necessary. |
- If the fan and all circuits test normal, replace the relay.
Repair Instructions
Repair Verification
Ignition ON, command the relay ON and OFF with a scan tool. Observe to verify that the fan turns ON and OFF with each command.
Cooling Fan Inoperative 2.4L
Diagnostic Instructions
Circuit/System Description
The engine control module (ECM) grounds the low speed relay, which is relay 1, and the high speed relay, which is relay 2, control circuits through an internal solid state device called a driver. The primary function of the driver is to supply
the ground for the component being controlled. Each driver has a fault line that is monitored by the ECM. When the ECM is commanding a component ON, the voltage potential of the control circuit should be low, near 0 volts. When the ECM is commanding the
control circuit to a component OFF, the voltage potential of the circuit should be high, near battery voltage. If the ECM detects that the actual state of the control circuit does not match the expected state, a DTC will set.
Reference Information
Schematic Reference
Engine Cooling Schematics
Connector End View Reference
Description and Operation
Cooling Fan Description and Operation
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Circuit/System Verification
- If DTCs P0480 or P0481 are set, then perform those diagnostics first.
- Ignition ON, command each relay ON and OFF with a scan tool. Observe to verify that the fan turns ON and OFF with each command.
Circuit/System Testing
- Ignition OFF, disconnect the affected relay.
- Connect a 30A fused jumper wire between the positive voltage terminal at the battery and the fan voltage supply circuit terminal and verify fan activation.
| • | Cooling fan 1 relay terminal Y1 |
| • | Cooling fan 2 relay terminal 87 |
| ⇒ | If the fan does not activate, test the fan voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal, test the fan ground circuit for an open/high resistance. If the fan did not activate and the
circuits test normal, replace the fan. |
- Ignition ON, connect a 30A fused jumper wire between the relay switch voltage supply circuit terminal and the fan voltage supply circuit terminal and verify fan activation.
| • | Cooling fan 1 relay terminal X3 and Y1 |
| • | Cooling fan 2 relay terminal 30 and 87 |
| ⇒ | If the fan does not activate, test the relay switch voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and it's fuse is open, test all connected components and replace as necessary. |
- If the fan and all circuits test normal, replace the relay.
Repair Instructions
Repair Verification
Ignition ON, command each relay ON and OFF with a scan tool. Observe to verify that each fan turns ON and OFF with each command.
