P2846: Shift Fork B Position Sensor Incorrect Neutral Position Indicated

What it means

The position sensor for shift fork B indicates the neutral position when the fork is mechanically engaged in a gear, or vice versa. Sensor reference offset.

At a glance

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

How it works

Shift fork B moves an internal selector, and its position sensor tells the TCM whether the fork is in neutral or engaged with a gear. P2846 sets when the sensor's neutral indication disagrees with the actual fork state, which can happen if the sensor reference is misadjusted or fork pin wear widens neutral travel.

Common causes

Most likely first.

1. Sensor mechanically misadjusted from neutral
2. Fork pin worn — neutral travel widened

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. Save freeze-frame data and compare fork B's reported neutral or engaged state with the commanded gear in TCM live data.
2. Inspect the fork B sensor mounting and connector for looseness or damage that could shift its neutral reference.
3. Check fork B sensor wiring, supply, and ground against the manufacturer's specification to rule out an electrical cause for the incorrect state.
4. Using the manufacturer's procedure, verify the fork B sensor reference against the mechanical neutral position.
5. If the reference is correctly set, inspect the fork B pin and selector for wear that could allow excess travel around neutral.

Common fixes

• Correct fork B sensor alignment using the manufacturer's procedure.
• Repair connector or wiring faults affecting fork B position feedback.
• Replace a worn fork B pin or selector component if inspection confirms excess neutral travel.
• Replace the fork B position sensor if it continues to indicate the wrong state after alignment and wiring checks.

Can I keep driving?

Avoid driving if the transmission slips, misses shifts, or cannot reliably engage a gear; fork B's neutral indication may not match its mechanical position. If it shifts normally, keep driving brief and arrange diagnosis before the condition worsens.