What does it mean?
P1480 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Low Fan Monitor Circuit Does Not Go HIGH When Commanded ON .
Symptoms
- MIL on
- Low speed cooling fan does not run
- Coolant temperature rises at idle and in slow moving traffic
- A/C cooling weakens noticeably when the vehicle is stopped
- The fan may only ever run at high speed, coming on later than it should
Likely causes
- Failed low speed fan relay with open or burnt contacts
- Open in the monitor feedback wire between the relay output and the module
- Blown fuse or fusible link in the fan power feed
- Seized or internally open fan motor, so no voltage appears on the monitored line
- Corroded terminals in the relay socket or at the fan connector
- Poor ground for the fan circuit
- Module monitor input fault
How to fix it
- Command the low speed fan on with a scan tool and check for voltage at the fan connector
- Inspect the relay, its socket and the related fuses for burnt terminals and open elements
- Back-probe the monitor wire while the fan is commanded and watch whether the voltage rises
- Apply power to the fan motor with a fused jumper to confirm the motor itself spins
- Check continuity of the monitor wire from the relay output to the module pin
- Repair the wiring, or replace the relay or fan motor as the tests indicate
- Verify normal fan staging and stable coolant temperature after the repair