A5 Check Circuit 91 (BK/BL) For Open

- Turn ignition switch OFF.

- Disconnect anti-lock brake module connector.

- Using an ohmmeter connected to a known good ground, measure resistance at module connector Pins C2-5 and C2-14, circuit 91 (BK/BL) to ground.

- Is resistance 5 ohms or less?

YES -- Problem is with multiplex communication network.

NO -- Service circuit 91 (BK/BL) for open. Restore vehicle. Retest system.