What does it mean?
P1435 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Secondary Air Injection System Pump Relay Circuit Short to Ground .
Symptoms
- MIL on and the secondary air monitor stays incomplete
- Air pump runs when it should be off, sometimes right after the key is turned on
- Continuous pump noise and possible pump overheating
- Battery drain if the pump keeps running with the engine off
- Repeated blown fuse in the air injection circuit
Likely causes
- Control wire rubbed through to ground on a bracket or body edge
- Water in the relay socket or fuse box creating a path to ground
- Relay coil internally shorted to the relay case
- Crushed harness at a clip, grommet or under a fuse box mounting
- Corroded terminals allowing the control pin to touch a ground pin
- Salt and road spray damage to the harness under the vehicle
- PCM low side driver internally shorted, only after the harness is verified
How to fix it
- Remove the relay and inspect the socket and fuse box for water and corrosion, drying them before retesting
- Measure resistance from the control terminal in the socket to ground; near zero confirms a short
- Disconnect the PCM connector and repeat the measurement to separate the harness from the module
- Check the relay coil for continuity to the relay case or mounting tab
- Inspect the harness route for crushed or chafed insulation, particularly at clips and grommets
- Repair the shorted section and secure the harness away from sharp edges
- Replace the relay if internally shorted, replace any blown fuse, then confirm the pump only runs during the cold start period