What it means
The TCM cannot read a valid signal from the clutch B pressure sensor. Open wiring or sensor failure.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The clutch B pressure sensor reports hydraulic pressure to the transmission control module so it can assess clutch operation. This code sets when the module cannot obtain a valid pressure signal, commonly because the signal wire is open, the sensor has failed or a connector pin has backed out.
Common causes
Most likely first.
- Open in sensor signal wire
- Pressure sensor failed
- Pin pushed back out of connector body
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
- Record freeze-frame data and scan clutch B pressure readings and related hydraulic faults to confirm whether pressure feedback is missing.
- Inspect the pressure-sensor connector for corrosion, fluid intrusion, poor fit or a terminal pushed back into the connector body.
- Check the sensor signal wire and its routing for breaks, chafing or damage between the sensor and transmission control module.
- With power isolated according to the manufacturer's procedure, test signal-wire continuity and terminal contact across the circuit.
- If wiring and connections pass, test sensor supply, ground and pressure-signal output against the manufacturer's specification.
Common fixes
- Reseat a pushed-back pressure-sensor terminal and secure the connector.
- Repair an open or damaged pressure-sensor signal wire.
- Clean or replace corroded pressure-sensor connector terminals.
- Replace the clutch B pressure sensor if its output fails the specified test.
Can I keep driving?
Avoid driving if shifts are slipping, harsh or delayed, since the transmission cannot reliably confirm clutch B hydraulic pressure and may enter limp mode. If the vehicle still shifts normally, limit driving and stop if slipping or loss of a gear develops.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.