What it means
The clutch B actuator control circuit reports a control circuit low condition. Clutch B engagement cannot be commanded reliably.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The TCM uses the Clutch B actuator control circuit to engage or release Clutch B and monitors the circuit's electrical level. This code sets when the circuit reads lower than expected, which can result from a wire shorted to ground, an internally shorted actuator coil, or resistance at corroded connector pins.
Common causes
Most likely first.
- Control wire shorted to ground
- Internal short in actuator coil
- 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
- Save freeze-frame data and check whether the low reading appears when the TCM commands Clutch B.
- Inspect the Clutch B actuator wiring and connector for chafing to ground, moisture, corrosion, or damaged terminals.
- With the circuit isolated as specified by the manufacturer, check whether the control wire is shorted to ground.
- Check the actuator coil and connector voltage drop against the manufacturer's specification to distinguish an internal short from high-resistance contacts.
- If the actuator and wiring pass, inspect the TCM-side connector and control circuit using the manufacturer's procedure.
Common fixes
- Repair a control wire that is shorted to ground.
- Clean corroded Clutch B actuator terminals and restore a sound connection.
- Repair damaged wiring or replace terminals causing excessive resistance.
- Replace the Clutch B actuator if its coil is confirmed shorted.
Can I keep driving?
Avoid driving if the transmission slips, shudders, or cannot make a reliable shift; stop if it loses drive or enters limp mode. Continued Clutch B control problems can overheat or damage the clutch.
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.