DTC P0480, P0481, or P0691 2.2L (L61)
Circuit Description
Battery positive voltage is supplied to the cooling fan relay through the 30 A cooling fan fuse located in the underhood fuse block. The engine control module (ECM) controls the cooling fan relay by grounding the cooling fan relay control circuit 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 which 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 fault detection circuit senses a voltage other than what is expected, the DTC will set.
The ECM will monitor the control circuit for the following:
| • | A short to ground |
| • | A short to voltage |
| • | An open circuit |
| • | An open relay coil |
| • | An internally shorted or excessively low resistance relay coil. |
When the ECM detects any of the above conditions, the DTC will set and the affected driver will be disabled.
Conditions for Running the DTC
| • | The ignition is ON. |
| • | The battery voltage is more than 9.0 volts. |
Conditions for Setting the DTC
| • | The ECM detects an open, a short to ground or a short to voltage on the cooling fan relay control circuit. |
| • | The condition must be present for a minimum of 6 seconds. |
Action Taken When the DTC Sets
| • | The ECM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed. |
| • | The ECM will store conditions which were present when the DTC set as Freeze Frame and Failure Records data. |
Conditions for Clearing the MIL/DTC
| • | The ECM will turn OFF the MIL during the third consecutive trip in which the diagnostic has been run and passed. |
| • | The History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction. |
| • | The DTC can be cleared by using the scan tool. |
Diagnostic Aids
| • | If the condition is not present, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
| • | Review the Freeze/Failure Records vehicle mileage since the diagnostic test last failed. This may help determine how often the condition that caused the DTC to be set occurs. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
Listen for an audible click when the cooling fan relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
-
Tests for voltage at the coil side of the cooling fan relay. The cool fan fuse supplies power to the cooling fan relay.
-
Verifies that the ECM is providing ground to the cooling fan relay.
-
Tests if ground is constantly being applied to the cooling fan relay.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Engine Cooling Schematics Connector End View Reference: Cooling System Connector End Views | |||
1 | Did you perform the Engine Cooling Diagnostic System Check? | Go to Step 2 | |
Does the cooling fan relay turn ON and OFF with each command? | Go to Diagnostic Aids | Go to Step 3 | |
Does the test lamp illuminate? | Go to Step 4 | Go to Step 8 | |
Does the test lamp turn ON and OFF with each command? | Go to Step 10 | Go to Step 5 | |
Does the test lamp remain illuminated with each command? | Go to Step 7 | Go to Step 6 | |
6 | Test the control circuit of the cooling fan relay for a short to voltage or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 14 | Go to Step 9 |
7 | Test the control circuit of the cooling fan relay for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 14 | Go to Step 9 |
8 | Test the battery positive voltage circuit of the cooling fan relay for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 14 | Go to Step 11 |
9 | Inspect for poor connections at the harness connector of the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 14 | Go to Step 13 |
10 | Inspect for poor connections at the cooling fan relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 14 | Go to Step 12 |
11 | Repair the cooling fan motor supply voltage circuit for a short to ground. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 14 | -- |
12 | Replace the cooling fan relay. Did you complete the replacement? | Go to Step 14 | -- |
13 |
Important: Perform the programming procedure for the ECM. Replace the ECM. Refer to Engine Control Module Replacement in Engine Controls - 2.2L (L61). Did you complete the replacement? | Go to Step 13 | -- |
14 |
Does the DTC reset? | Go to Step 2 | System OK |
DTC P0480, P0481, or P0691 2.0L (LSJ)
Circuit Description
The powertrain control module (PCM) controls the low speed cooling fan operation by grounding the low speed fan relay control circuit with an internal solid state device called a driver. For high speed cooling fan operation, the PCM grounds the high speed and S/P relay control circuit at the same time the low speed control circuit is grounded. Battery positive voltage is supplied to the low speed, high speed and S/P fan relays. 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 potential of the control circuit should be high, near battery voltage. If the fault detection circuit senses a voltage other than what is expected, the DTC will set. The vehicle has DTCs which include DTC Symptoms. For more information on DTC Symptoms, refer to in Vehicle DTC Information.
If the PCM detects an improper voltage level on the low or high speed driver circuits, then code P0480, P0481, or P0691 will set and the effected driver will be disabled.
| • | P0480 -- Cooling Fan Relay 1 Control Circuit |
| • | P0481-- Cooling Fan Relays S/P and Relay 2 Control Circuit |
| • | P0691 -- Cooling Fan Relay 1 Control Circuit Low Voltage |
Conditions for Running the DTC
| • | The ignition voltage is between 9.0-18.0 volts. |
| • | The engine speed is more than 40 RPM. |
| • | The PCM driver transitions from ON to OFF or from OFF to ON. |
Action Taken When the DTC Sets
| • | The PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed. |
| • | The PCM will store conditions which were present when the DTC set as Freeze Frame and Failure Records data. |
Conditions for Clearing the MIL/DTC
| • | The PCM will turn OFF the MIL during the third consecutive trip in which the diagnostic has been run and passed. |
| • | The History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction. |
| • | Use the scan tool Clear DTC Information function. |
Diagnostic Aids
| • | If the condition is not present, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
| • | Review the Freeze/Failure Records vehicle mileage since the diagnostic test failed. This may help determine how often the condition that caused the DTC to be set occurs. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
Listen for an audible click when the cool fan relay 1 operates. Command both the ON and OFF states. Repeat the commands as necessary.
-
Listen for an audible click when the S/P and cool fan 2 relays operate. Command both the ON and OFF states. Repeat the commands as necessary.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Engine Cooling Schematics Connector End View Reference: Cooling System Connector End Views | |||
1 | Did you perform the Diagnostic System Check-Vehicle? | Go to Step 2 | |
Does the low speed cooling fans engage? | Go to Step 3 | Go to Step 4 | |
|
Important: A 3 second delay occurs before the powertrain control module (PCM) changes the cooling fan speed.
Are the S/P and the cool fan 2 relays turned ON? | Go to Diagnostic Aids | Go to Step 6 | |
4 |
Does the test lamp illuminate? | Go to Step 5 | Go to Step 16 |
5 |
Does the test lamp illuminate? | Go to Step 12 | Go to Step 9 |
6 |
Does the test lamp illuminate? | Go to Step 7 | Go to Step 16 |
7 |
Is the test lamp illuminated? | Go to Step 14 | Go to Step 8 |
8 |
Does the test lamp illuminate? | Go to Step 13 | Go to Step 9 |
9 | Intermittently ground then remove the ground on the High Speed Cooling Fan Relay Control Circuit to the PCM. Does the test lamp remain illuminated upon grounding the control circuit? | Go to Step 11 | Go to Step 10 |
10 | Test the control circuit of the appropriate relay for a short to voltage or an open. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 21 | Go to Step 15 |
11 | Test the control circuit of the appropriate relay for a short to ground. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 21 | Go to Step 15 |
12 | Inspect for poor connections at the cool fan 1 relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 21 | Go to Step 17 |
13 | Inspect for poor connections at the S/P fan relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 21 | Go to Step 18 |
14 | Inspect for poor connections at the cool fan 2 relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 21 | Go to Step 19 |
15 | Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 21 | Go to Step 20 |
16 | Repair the battery voltage circuit for an open or high resistance. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 21 | -- |
17 | Replace the cool fan 1 relay. Did you complete the repair? | Go to Step 21 | -- |
18 | Replace the S/P fan relay. Did you complete the repair? | Go to Step 21 | -- |
19 | Replace the cool fan 2 relay. Did you complete the repair? | Go to Step 21 | -- |
20 |
Important: Perform the programming procedure for the PCM. Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls - 2.0L. Did you complete the replacement? | Go to Step 21 | -- |
21 |
Does the DTC reset? | Go to Step 2 | System OK |
