C054D: Vacuum Sensor B Circuit/Open

What it means

The control module monitors the signal circuit for vacuum sensor B. It sets this code when the circuit is detected as open and the sensor signal is unavailable.

How it works

Vacuum sensor B supplies the control module with a signal used to assess the available vacuum for brake assist. The module sets C054D when it detects an open in sensor B's signal circuit and can no longer read that signal.

Common causes

Most likely first.

1. Signal wire open
2. Pin pushed back out of connector body
3. Cracked solder joint inside the module or sensor

Symptoms

• Brake or stability-control warning light on
• Brake assist may be affected

How to diagnose it

1. Use a scan tool to record the stored codes and freeze-frame data, then check whether vacuum sensor B's signal is missing.
2. Inspect sensor B's connector for a backed-out pin, corrosion, looseness, or damage that could interrupt the signal.
3. Trace the signal wire from vacuum sensor B to the control module and look for breaks, chafing, or prior repairs.
4. With the circuit identified from vehicle wiring information, check continuity of the signal wire and inspect its terminals for a poor connection.
5. If the wiring and terminals pass, check the sensor and module connections for an internal open or cracked solder joint using vehicle-specific diagnostic procedures.

Common fixes

• Reconnect sensor B's loose connector or properly seat a pushed-back terminal.
• Repair an open or damaged section of the sensor B signal wire.
• Clean or replace corroded or damaged connector terminals and restore the connector seal.
• Repair or replace the sensor or control module if testing confirms an internal open.

Can I keep driving?

Drive cautiously and leave extra stopping distance because brake assist may be reduced. If braking effort changes or a brake warning appears, stop somewhere safe and arrange assistance.