P0653 — Sensor reference voltage B — electrical input high

The monitor for sensor reference voltage b detects an electrical value above the allowed range; this does not by itself prove physically excessive speed, pressure or temperature. A, B and C label different reference circuits, not fixed lists of sensors across makes. The definition does not mean a traction high-voltage fault.

Affected system: Sensor reference-voltage circuits

Symptoms

• Warning light may illuminate
• Related system function may be impaired
• Vehicle-specific symptoms vary

Possible causes

• Low or unstable supply voltage, fuse or relay fault, poor ground, or wiring damage
• Related wiring, connector, power or ground fault
• Vehicle-specific mechanical or control issue

What to check

• Record stored and pending codes and freeze-frame data
• Measure battery and charging voltage under load and compare with scan data; test the named circuit, fuse, relay, grounds and connectors.
• Confirm measured values against the vehicle service information
• Retest under the conditions that set the code
• Measure battery and charging voltage under load and compare with scan data; test the named circuit, fuse, relay, grounds and connectors.
• Repair the verified cause and confirm the code does not return

Also written as: P0653-00, P065300, PO653 (some scan tools add the fault-type byte, e.g. -00).