Astra J
DTC P1484 (LBS w/o M36, LBY w/o M36, or LSF)Diagnostic Instructions
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| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptor
| DTC P1484: Cooling Fan System Performance |
Diagnostic Fault Information
Cooling Fan Medium Speed Relay
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Circuit |
Short to Ground |
High Resistance |
Open |
Short to Voltage |
Signal Performance |
|---|---|---|---|---|---|
Relay Coil Ignition |
P0693 |
P0693 |
P0481 |
- |
- |
Relay Switch B+ |
1 |
1 |
1 |
- |
- |
Relay Coil Control |
P0693 |
P0693 |
P0481 |
P0694 |
P1484 |
Relay Output Control |
1 |
1 |
1 |
2 |
- |
1. Fan Inoperative Without a DTC. 2. Fan Always ON Without a DTC. |
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Cooling Fan High Speed Relay
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Circuit |
Short to Ground |
High Resistance |
Open |
Short to Voltage |
Signal Performance |
|---|---|---|---|---|---|
Relay Coil Ignition |
P0695 |
P0695 |
P0482 |
- |
- |
Relay Switch B+ |
1 |
1 |
1 |
- |
- |
Relay Coil Control |
P0695 |
P0695 |
P0482 |
P0696 |
P1484 |
Relay Output Control |
1 |
1 |
1 |
2 |
- |
1. Fan Inoperative Without a DTC. 2. Fan Always ON Without a DTC. |
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Circuit/System Description
The engine control module (ECM) commands the fans ON in either high speed, medium speed, or low speed, depending on cooling requirements.
Low Speed
In low speed operation, the ECM applies ground to the coil side of the cooling fan low speed relay with the cooling fan relay 1 control circuit. This energizes the relay coil. The low speed cooling fan relay supply power to the cooling fan motor through an internal fan resistor.Medium Speed
In medium speed operation, the ECM commands the medium speed fan relay on. This energizes the relay coil. The medium speed cooling fan relay supply power to the cooling fan motor through an internal fan resistor. The cooling fan is connected to a dedicated ground, and operates at medium speed.High Speed
In high speed operation, the ECM applies a ground to the coil side of all the high speed cooling fan relay. When energized, the high speed relays apply voltage directly to the cooling fan through the switch side of the relay.Conditions for Running the DTC
| • | The ignition voltage is between 8-18 V. |
| • | The engine is running greater than or equal to 400 RPM. |
Conditions for Setting the DTC
The ECM detects an over current at the output powerstage.
Action Taken When the DTC Sets
DTC P1484 is a Type A DTC.
Conditions for Clearing the DTC
DTC P1484 is a Type A DTC.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Cooling System Description and Operation
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
| 1. | Verify that DTCs P0480, P0481, P0482, P0691, P0962, P0693, P0694, P0695 or P0696 are not present. |
| ⇒ | If DTC is present, refer to DTC P0480-P0482 or P0691-P0696 . |
| 2. | Command the Cooling Fan Relay 1 ON and OFF with a scan tool. The cooling fan motor should turn ON at low speed and OFF when changing between the commanded states. |
| ⇒ | If the cooling fan motor does not operate correctly, refer to Circuit/System Testing. |
| 3. | Command the Cooling Fan Relay 2 ON and OFF with a scan tool. The cooling fan motor should turn ON at medium speed and OFF when changing between the commanded states. |
| ⇒ | If the cooling fan motor does not operate correctly, refer to Circuit/System Testing. |
| 4. | Command the Cooling Fan Relay 3 ON and OFF with a scan tool. The cooling fan motor should turn ON at high speed and OFF when changing between the commanded states. |
| ⇒ | If the cooling fan motor does not operate correctly, refer to Circuit/System Testing. |
Circuit/System Testing
| 1. | Ignition OFF, disconnect the relays listed below: |
| • | KR20B Cooling Fan Medium Speed 2 Relay |
| • | KR20D Cooling Fan High Speed Relay |
| 2. | Ignition ON, command the Cooling Fan Relay 1 ON and OFF with a scan tool and verify the DTC does not reset. |
| ⇒ | If the DTC resets, test or replace the KR20C Cooling Fan Low Speed Relay and verify the DTC does not reset. If the DTC resets, replace the K20 Engine Control Module. |
| 3. | Connect the KR20B Cooling Fan Medium Speed 2 Relay. |
| 4. | Command the Cooling Fan Relay 2 ON and OFF with a scan tool and verify the DTC does not reset. |
| ⇒ | If the DTC resets, test or replace the KR20B Cooling Fan Medium Speed 2 Relay and verify the DTC does not reset. If the DTC resets, replace the K20 Engine Control Module. |
| 5. | Connect the KR20D Cooling Fan High Speed Relay. |
| 6. | Command the Cooling Fan Relay 3 ON and OFF with a scan tool and verify the DTC does not reset. |
| ⇒ | If the DTC resets, test or replace the KR20B Cooling Fan Medium Speed 2 Relay and verify the DTC does not reset. If the DTC resets, replace the K20 Engine Control Module. |
| 7. | If all circuits test normal, test or replace K20 Engine Control Module. |
Component Testing
Dynamic Test
| 1. | Ignition OFF, disconnect the applicable relay. |
| 2. | Test for 70-110 Ω between terminals 85 and 86 of the relay. |
| ⇒ | If the resistance is not within the specified range, replace the relay. |
| 3. | Test for infinite resistance between the following terminals: |
| • | 30 and 86 |
| • | 30 and 87 |
| • | 30 and 85 |
| • | 85 and 87 |
| ⇒ | If not the specified value, replace the relay. |
| 4. | Install a 20 A fused jumper wire between relay terminal 85 and 12 V. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 Ω between terminals 30 and 87. |
| ⇒ | If greater than the specified value, replace the relay. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for Engine Control Module replacement, programming and setup |
Repair Verification
| 1. | Ignition ON, verify with a scan tool that the ECM is not commanding fan activation. |
| 2. | Ignition ON, observe that the fan is not activated. |
Ignition ON, verify with a scan tool that the ECM is not commanding fan activation. Ignition ON, observe that the fan is not activated.
