C1218: OBD-II code C1218 signals the ABS pump motor circuit is shorted to battery voltage or its ground path is open — ABS is disabled until fixed.

Symptoms

• The ABS and traction/stability control warning lamps are illuminated together on the dashboard.
• The ABS pump motor either runs continuously, does not run at all, or trips the ABS main relay or main fuse.
• Standard braking is unaffected but anti-lock functionality and stability control interventions are disabled.

Common causes

• A short to battery voltage on the pump motor drive circuit — often caused by chafed wiring near a battery terminal — is a frequent cause.
• An open pump motor ground path, whether through a corroded EBCM chassis ground point or a broken ground wire, will also trigger the code.
• A failed EBCM internal motor driver or an internally open pump motor winding causes the same fault pattern.

What to do?

With the EBCM connector unplugged, verify that no battery voltage reaches the pump motor drive pins with ignition on. Check the pump motor ground path resistance to chassis and inspect the EBCM chassis ground point for corrosion. If the wiring and ground both test good, the EBCM/BPMV assembly is at fault and needs replacement.