Skip to content
GTECH Calibration
Portal

P1498

High Speed Rad Fan Ground CTRL Rly Circuit.

  • Jeep
  • Powertrain
  • Manufacturer code
  • Medium severity

How this code is built

P
SystemPowertrain
1
Defined byThe manufacturer
4
AreaAuxiliary emission controls
98
FaultThe specific fault in that area

What it means

P1498 on a Jeep means the powertrain control module has detected a fault in the circuit that controls the high speed radiator fan ground control relay. The module commands the relay on or off and monitors the circuit, and the expected voltage did not match what it commanded, so the code was set. The fault is in the relay circuit, not necessarily the fan itself.

Symptoms

  • Engine cooling fan not running at high speed when the engine is hot or the air conditioning is on
  • Engine temperature rising in traffic or when idling
  • Air conditioning performing poorly at idle or in slow traffic
  • Fan running continuously at high speed when it should not
  • Check engine light on

Possible causes

  • Faulty high speed radiator fan ground control relaylikely
  • Open circuit, short to ground or short to voltage in the relay control wiringlikely
  • Corroded, loose or damaged connector at the relay, fuse box or powertrain control modulepossible
  • Blown fuse or poor power supply to the relaypossible
  • Poor earth connection on the fan circuitpossible
  • Internal fault in the powertrain control module driverrare

How to diagnose

  1. Read all stored codes and freeze frame data, noting engine temperature and whether the air conditioning was on when the code set
  2. Check the relevant fuses and the relay for damage, heat marks or corrosion
  3. Inspect the wiring and connectors between the relay, the fan and the powertrain control module for chafing, water ingress and green corrosion
  4. Use a scan tool that supports bidirectional control to command the fan and listen or watch for the relay and fan responding
  5. Swap the relay with a known good identical one, if the model has one in the same position, and retest
  6. Check the relay supply voltage and the earth connections with a multimeter, following the wiring diagram for your model and engine
  7. Test the control wire between the relay and the module for continuity, short to ground and short to voltage with the module disconnected
  8. Only once the wiring and relay are proven good, consider a fault in the powertrain control module

How to fix

  • Replace the faulty high speed fan relay
  • Repair or replace damaged wiring in the relay control circuit
  • Clean or replace corroded or loose connectors and terminals
  • Replace the blown fuse after finding out why it failed
  • Clean and tighten the fan circuit earth points
  • Repair or replace the powertrain control module only after confirming it is faulty

Can I keep driving?

Medium severity

Short trips in cool weather are usually possible, but without the high speed fan the engine can overheat in traffic or in hot weather. Fix it soon and stop at once if the temperature gauge climbs.

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

This code for other makes

Nearby codes