Faulty high speed fan control relay (burnt contacts or open or shorted coil); Damaged, chafed or corroded wiring between the relay and the powertrain control module; Corroded or loose relay socket or connector terminals; Blown fuse or fusible link in the relay power supply; Poor earth connection on the relay or fan circuit; Faulty fan motor drawing excess current and damaging the relay circuit; Internal fault in the powertrain control module relay driver.

P1489

High Speed Fan CTRL Relay Circuit Open Or Shorted.

Plymouth
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 Plymouth means the powertrain control module has detected a fault in the high speed radiator fan control relay circuit. The module monitors the relay driver and saw a voltage that did not match what it commanded, pointing to an open circuit or a short to power or earth. The exact circuit layout varies by model and engine, so check the wiring diagram for the vehicle.

Symptoms

Engine warning light on
Engine running hot or temperature gauge climbing in traffic
High speed cooling fan not running or running constantly
Air conditioning performing poorly when stationary
Cooling fan staying on after the engine is switched off

Possible causes

Faulty high speed fan control relay (burnt contacts or open or shorted coil)likely
Damaged, chafed or corroded wiring between the relay and the powertrain control modulelikely
Corroded or loose relay socket or connector terminalslikely
Blown fuse or fusible link in the relay power supplypossible
Poor earth connection on the relay or fan circuitpossible
Faulty fan motor drawing excess current and damaging the relay circuitpossible
Internal fault in the powertrain control module relay driverrare

How to diagnose

Read all stored and pending codes and note the freeze frame data, including coolant temperature and whether the air conditioning was on
Check the engine coolant level and condition first, since overheating can occur alongside this fault
Visually inspect the relay, its socket, the fuses and the wiring for heat damage, corrosion, chafing or water ingress
Swap the relay with a known good identical one, if the wiring diagram shows a matching relay, and see if the fault changes
Use a bidirectional scan function, if available, to command the high speed fan on and off and listen for the relay clicking
Test the relay coil and contacts for resistance and check for battery voltage and a good earth at the socket
Check continuity and short to earth or power on the control wire between the relay and the module, following the wiring diagram
Check the fan motor current draw and the connector for signs of overheating

How to fix

Replace the faulty high speed fan relay with one of the correct specification
Repair or replace damaged wiring and renew corroded connectors or relay socket terminals
Replace the blown fuse or fusible link after finding the reason it failed
Clean and tighten earth connections or repair the earth path
Replace the fan motor or fan assembly if it is drawing excessive current
Repair or replace the powertrain control module only after wiring, relay and supply have been proven good

Can I keep driving?

Medium severity

The car can usually be driven for a short time if the fan still works and the temperature stays normal, but keep an eye on the temperature gauge. Avoid heavy traffic and long journeys until it is fixed, and stop if the engine begins to overheat.

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