Technical Description of OBD-II Trouble Code
The circuit for the clutch position sensor is experiencing intermittent issues.
What does that mean?
This is a generic diagnostic trouble code (DTC) for the powertrain and is applicable to many OBD-II vehicles (1996-newer), including Dodge, Ford, Smart, Land Rover, Chevrolet, Chrysler, Jeep, Mercedes, Toyota, etc. The exact repair steps may vary depending on the year, make, model, and powertrain configuration.
The clutch position sensor circuit is monitored by the Power Control Module (PCM) or the Transmission Control Module (TCM), depending on the specific vehicle.
The purpose of the clutch position sensor circuit is to monitor the status of the clutch on a manual transmission. This is done by reading the output voltage of the clutch position sensor, which indicates when the clutch is engaged. In most cases, the clutch position sensor is a basic on/off switch mounted near the clutch foot pedal on the support bracket. One side of the switch typically has constant voltage, and engaging the clutch closes the contacts, transferring voltage to the starter or starter solenoid. This circuit and switch prevent the engine from starting before the clutch is engaged.
When the PCM or TCM detects an intermittent voltage or resistance problem in the clutch position sensor circuit, it sets code P0809 and illuminates the check engine light or the transmission warning lamp.
A clutch position sensor:
What is the severity of this DTC?
This code is typically of moderate severity, but it can be severe if the vehicle starts with the clutch disengaged, creating a safety issue.
What are some of the symptoms of the code?
Symptoms of a P0809 trouble code may include:
What are some of the common causes of the code?
Causes for this P0809 code may include:
What are some P0809 troubleshooting steps?
The first step in the troubleshooting process for any malfunction is to research the Technical Service Bulletins (TSB’s) for the specific vehicle by year, model, and power plant. In some cases, this can save a lot of time by pointing you in the right direction.
The second step is to locate the clutch position sensor switch and inspect it for any obvious physical damage. Perform a thorough visual inspection of the associated wiring for any defects such as scraping, rubbing, bare wires, or burn spots. Next, check the connectors and connections for security, corrosion, and damaged pins. This process should include all wiring connectors and connections to the clutch position sensor switch, PCM, starter, and starter solenoid. Consult the specific technical data for the vehicle to see if a fuse or fuse-able link is part of the circuit.
Advanced Steps
The advanced steps are highly specific to the vehicle and require advanced equipment for accurate performance. These procedures involve using a digital multimeter and referring to the specific technical references for the vehicle. The technical data will include troubleshooting charts and the appropriate sequence to follow for an accurate diagnosis.
Voltage Checks
When the clutch is disengaged, there should be approximately 12 volts on one side of the sensor. When the clutch is engaged, there should be voltage on both sides of the sensor. The starter solenoid or starter should also have power based on the configuration.
If this process reveals the absence of a power source or ground, continuity testing may be required to check the integrity of the wiring, connectors, and other components. Continuity tests should always be performed with the power removed from the circuit, and the normal readings for wiring and connections should be 0 ohms of resistance. Resistance or no continuity indicates faulty wiring that is open or shorted and must be repaired or replaced. A continuity test from the PCM or TCM control to the frame will confirm the serviceability level of ground straps and ground wires. The presence of resistance indicates a loose connection or possible corrosion.
What are some common repairs for this code?
Common Mistake
We always recommend seeking professional service to resolve this issue. However, if that is not possible, we offer the option to permanently delete this specific DTC. All other codes will continue to function. If you are interested in this option, please upload your ECU file to our portal.
