Clutch Actuator Circuit Open
What does P0900 mean?
The P0900 code means the vehicle's onboard diagnostic system has detected: Clutch Actuator Circuit Open. This is a critical severity code.
Common Symptoms
- Check Engine Light illuminated
- Automated manual transmission will not engage or disengage clutch
- Vehicle will not move or stalls immediately
- Transmission stuck in neutral
Probable Causes (Ranked by Likelihood)
- Faulty clutch actuator motor Very High
- Open circuit in clutch actuator wiring High
- Disconnected connector at clutch actuator Moderate
- TCM output driver failure Low
Step-by-Step Diagnostic Procedure
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Check the clutch actuator connector is fully seated
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Measure resistance at the clutch actuator motor terminals
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Test for continuity in the wiring between the TCM and actuator
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Command the clutch actuator with a bidirectional scan tool
Frequently Asked Questions
What is a clutch actuator?
In automated manual transmissions, the clutch actuator is an electric or hydraulic motor that engages and disengages the clutch automatically instead of a driver-operated pedal.
Can I drive at all with P0900?
No, if the clutch actuator circuit is open, the transmission cannot engage the clutch and the vehicle will not move. Have it towed to a repair facility.
Is this code specific to automated manual transmissions?
Yes, P0900 applies to vehicles with automated manual transmissions (AMT) or dual-clutch transmissions (DCT) that use an electrically or hydraulically controlled clutch actuator.