P0903 OBD-II Trouble Code: Clutch Actuator Circuit Malfunction

Check Engine Light

P0903 OBD-II Trouble Code: Clutch Actuator Circuit Malfunction

Diagnostic Trouble Code (DTC): P0903

P0903 code definition

P0903 is the OBD-II code for Clutch Actuator Circuit Malfunction. Other codes in the P0900 series may accompany this fault.

What the P0903 code means

In a vehicle with a manual transmission or semi-automatic transmission, there is a clutch actuation system consisting of various components like the clutch pedal, the clutch master cylinder, the clutch slave cylinder, and the clutch pipe. The clutch actuator acts as a link between the gearbox and the pedal, allowing you to engage the gears as you drive. The TCM (transmission control module) operates this actuator, triggering clutch disengagement via the clutch master cylinder. The TCM also keeps track of the clutch motor voltage and detects any aberrations within the circuit. When the clutch actuator circuit sends a message to the TCM indicating current values outside of the norm, code P0903 is set, alerting you to a fault that is affecting the circuit.

What causes the P0903 code?

There are limited conditions that generally cause this code to set, including:

  • A short or open in the clutch motor circuit
  • Faulty or damaged wiring
  • A bad clutch actuator assembly
  • Loose or faulty actuator harness or connectors
  • Rarely, a bad TCM or PCM

What are the symptoms of the P0903 code?

When the clutch actuator circuit is compromised, the actuator may malfunction. This can result in stalling, harsh shifting or failure to shift, and damage to other components within the clutch system.

How does a mechanic diagnose the P0903 code?

In addition to verifying the stored codes using a scanner, and addressing any accompanying issues in the order in which the events occurred, the technician may perform the following tasks to diagnose the problem:

  • Inspection of TCM terminal voltage
  • Inspection of TCM terminal condition
  • Inspection of the clutch actuator circuit
  • Inspection of the clutch actuator harness and connector
  • Clutch actuator assembly inspection

Common mistakes when diagnosing the P0903 code

The clutch actuator may be replaced automatically without doing a thorough inspection of the terminals, wiring, and voltage signals. A thorough inspection of the entire clutch actuator assembly should be performed before deciding which parts to replace, in order to avoid costly, unnecessary repairs.

How serious is the P0903 code?

This code indicates a very serious situation which can prevent the vehicle from being operational. The transmission problems created by a faulty clutch actuator circuit could put you in potential danger if your vehicle malfunctions on the road. Even if you’re still able to drive your vehicle with an active P0903 code, you should take it to a mechanic as soon as possible in order to prevent further damage and to protect your safety and the safety of your passengers.

What repairs can fix the P0903 code?

Repairing this code may involve repairing faulty wiring or connectors, replacing TCM terminals, replacing the clutch actuator itself, or – in rare cases – replacing the TCM. Once these repairs take place, the technician will put the car through one or more drive cycles to make sure the fault code doesn’t return.

Additional comments for consideration regarding the P0903 code

One of the most important things to remember when dealing with repairs in a multi-mode transaxle transmission system is that when a component of the system is replaced, the repair must be followed up with an initialization and learning procedure. Essentially this is a synchronization process which facilitates the entire system working in harmony with the new part. While code P0903 is considered almost universal, in some Dodge vehicles this code stands for Trans Fluid Deteriorated, which indicates a problem the condition of the transmission fluid. This too is a serious condition which can cause severe damage to the transmission, resulting in complicated, expensive repairs. Whether you get this code in a Dodge, or other make of vehicle, it is crucial to have it assessed by a professional as soon as possible.

Need help with a P0903 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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