P28CB: Clutch A Motor Position Sensor Circuit/Open

The TCM cannot read a valid signal from the clutch A motor rotor position sensor. Open wiring or sensor failure.

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

Most likely causes

• Open in sensor signal wire
• Position sensor failed
• Pin pushed back out of connector body

What to check, in order

Start with the simplest. You can tick off each step.

1. Check the fluid level and condition
2. Check the continuity of the wire between the component and the control module.
3. Read the input and output speed in live data
4. Check the connector and wiring
5. Check for other related engine codes
6. Consult the manufacturer's procedure for the transmission

Good to know

• Repair difficulty: hard
• It can trigger limp mode.

What each character of P28CB means

• P: Powertrain: engine and transmission
• 2: Generic code: same on every make
• 8: Transmission
• CB: Specific fault in that system

Frequently asked questions

Can I keep driving with code P28CB?

Drive gently to a repair shop. If it slips, you hear clunks, or it loses its gears, do not keep driving.

What causes code P28CB?

The most common causes are: open in sensor signal wire; position sensor failed; pin pushed back out of connector body.

Related codes

• P28DAClutch B Motor Position Sensor Circuit/Open

Sources

• github.com: dtc database
• en.wikipedia.org: Brushless DC electric motor
• en.wikipedia.org: Dual clutch transmission

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.