What does it mean?
P1487 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: After Run Coolant Pump Control Circuit Issues (Emission-related cooling) .
Symptoms
- MIL on
- Coolant temperature spikes shortly after the engine is switched off
- Heat soak causes hard hot restarts or rough running immediately after a hot restart
- Coolant expansion tank overflows or pushes coolant out after shutdown
- No pump noise is heard after shutdown when it should be running
Likely causes
- Failed after run coolant pump or its control relay
- Open or shorted control circuit between the module and the pump relay
- Corroded connector at the pump, which sits low in the engine bay and collects water
- Blown fuse in the after run pump feed
- Pump impeller seized by scale, sealant residue or debris in the coolant
- Poor ground for the pump circuit
- Control module driver fault
How to fix it
- After a hot shutdown, listen at the pump to check whether it actually runs
- Inspect the pump connector and its harness for corrosion, water and physical damage
- Verify power and ground at the pump while the circuit is commanded on
- Test or substitute the relay that controls the pump
- Apply power directly to the pump with a fused lead to see whether the impeller turns
- Flush the cooling system if scale or debris is present, and replace a seized pump
- Repair wiring faults, then confirm after run operation and stable temperatures