P08B0: Neutral Position Sensor B Circuit High

What it means

The neutral position sensor B reports a circuit high fault. Verification of true neutral position on the B channel is impaired.

At a glance

• Usually lights the check-engine light
• The engine or gearbox may go into limp mode

How it works

Neutral position sensor B sends the transmission control module a signal used to confirm neutral. This code sets when the B-channel circuit voltage is above its expected range, preventing reliable neutral verification.

Common causes

Most likely first.

1. Position sensor failed
2. Wiring fault
3. Connector pins corroded - high contact resistance

Symptoms

• Check engine or transmission warning light on
• Harsh, delayed, or missing shifts
• Possible limp mode (locked in one gear)
• Slipping or shuddering during gear changes

How to diagnose it

1. Check freeze-frame and transmission live data to identify when sensor B went high and whether the reported neutral state matches the selected gear.
2. Inspect sensor B’s connector and harness for loose or corroded terminals, damaged insulation, or a signal wire shorted to voltage.
3. Check the sensor B supply, ground, and signal wiring against the wiring diagram and manufacturer’s specification.
4. Watch the B-channel signal while selecting neutral and other positions, and compare its behavior with sensor A if available.
5. If the circuit checks out, test sensor B using the manufacturer’s procedure to determine whether the sensor is stuck high.

Common fixes

• Repair a signal wire shorted to voltage or other damaged sensor B wiring.
• Clean and secure loose or corroded connector terminals.
• Replace a faulty neutral position sensor B.
• Carry out any required neutral-position relearn after repair.

Can I keep driving?

Do not continue driving if the transmission slips, shifts unpredictably, or enters limp mode, since the module may not be able to confirm neutral correctly. If operation remains normal, keep driving to a minimum until the circuit is checked.