Faulty high speed fan relay (failed coil or stuck contacts); Open circuit or chafed wiring between the relay and the control module; Corroded, loose or damaged relay socket or connector terminals; Blown fuse or fusible link feeding the relay circuit; Short to ground or to voltage in the relay control wire; Fault inside the engine control module driver circuit.

P1489

High Speed Fan CTRL Relay Circuit Open Or Shorted.

Pontiac
Powertrain
Manufacturer code
Medium severity

How this code is built

P: SystemPowertrain
1: Defined byThe manufacturer
4: AreaAuxiliary emission controls
89: FaultThe specific fault in that area

What it means

P1489 on a Pontiac means the engine control module has detected a fault in the circuit that controls the high speed cooling fan relay. The module monitors the relay control circuit and sets the code when the voltage it sees does not match what it commanded, which points to an open circuit or a short. The exact relay layout and fan arrangement depend on the model and engine, so check the wiring diagram for the specific vehicle.

Symptoms

Engine cooling fans not running at high speed
Engine running hot or temperature gauge climbing in traffic
Air conditioning performing poorly when stationary
Fans running constantly at high speed
Check engine light on
Possible overheating warning at idle or low speed

Possible causes

Faulty high speed fan relay (failed coil or stuck contacts)likely
Open circuit or chafed wiring between the relay and the control modulelikely
Corroded, loose or damaged relay socket or connector terminalslikely
Blown fuse or fusible link feeding the relay circuitpossible
Short to ground or to voltage in the relay control wirepossible
Fault inside the engine control module driver circuitrare

How to diagnose

Read the stored codes and freeze frame data, noting engine temperature and whether any other cooling or air conditioning codes are present
Check the relevant fuses and fusible links for the fan circuit using the vehicle wiring diagram
Inspect the relay, its socket and the connectors for corrosion, heat damage, bent or loose terminals
Swap the relay with a known good identical one, or bench test the relay coil resistance and contacts
Use a scan tool bidirectional control to command the high speed fan on and listen or watch for relay operation
Check the relay control wire for continuity back to the control module and test for shorts to ground or voltage with the connector unplugged
Check the relay power supply and earth under load with a multimeter
If everything else is sound, check the module driver output and connector before suspecting the module

How to fix

Replace the faulty high speed fan relay with the correct specification part
Repair or replace damaged, open or shorted wiring in the relay control circuit
Clean or replace corroded relay socket terminals and connectors
Replace the blown fuse or fusible link after finding and fixing the cause of the overload
Repair or replace the engine control module only after wiring and relay faults are ruled out

Can I keep driving?

Medium severity

Short, gentle journeys may be possible, but without the high speed fan the engine can overheat in traffic or at idle. Get it fixed soon and stop driving if the temperature gauge rises.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.