Possible Causes
WARNING: This page is about a different car, the 2020 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.
- Wiring, terminals or connectors
- HydroMax pump motor relay
- ABS module
- CU1: CHECK PUMP MOTOR RELAY COIL GROUND CIRCUIT FOR AN OPEN
- Ignition OFF.
- CU2: CHECK PUMP MOTOR RELAY COIL GROUND CIRCUIT FOR A SHORT TO GROUND
- Measure the resistance between:
(+) HydroMax Relay Connector, Harness Side (-) HRC Ground - Is the resistance greater than 10, 000 ohms?
Yes No Go to CU3. REPAIR the circuit.
- Measure the resistance between:
- CU3: CHECK PUMP MOTOR RELAY COIL GROUND CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) HydroMax Relay Connector, Harness Side (-) HRC Ground - Is any voltage present?
Yes No REPAIR the circuit. Go to CU4.
- CU4: CHECK FOR CORRECT ABS MODULE OPERATION
- Ignition OFF.
- Inspect the ABS module electrical connector and the HydroMax relay socket.
- Repair:
- corrosion (install new connector, socket or terminal - clean module or relay pins)
- damaged or bent pins - install new terminals or pins
- pushed-out pins - install new pins as necessary