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Error Code P081E is defined as Excessive Clutch B Slippage. Error Code P081E is a generic trouble code, meaning it applies to all vehicles with the OBD-II system, especially those made from 1996 up to present. This includes vehicles from, but not limited to, Acura, Audi, Honda, Porsche, and Volkswagen. Specifications on the definition, troubleshooting, and repairs, of course, vary between make, model, and powertrain configuration.
If a vehicle stores this error code, that means the PCM (powertrain control module) has determined a data input signal from the input and output speed sensor that says the clutch is slipping excessively. The “B” in the definition means the vehicle is equipped with the clutch (pedal) position sensor (CPPS), which works similarly to the throttle position sensor (TPS).
The TCM (transmission control module) is sometimes a standalone unit. In recent years, however, it’s been commonly integrated into the single housing of the ECM (engine control module). This component is now referred to as the PCM.
To calculate the maximum allowable degree of transmission (clutch) slippage, the PCM uses input signals from multiple engine transmission. Excessive clutch slippage happens when there is a clutch disc and pressure plate wear, as well as mechanical failure. These discrepancies in the CPPS voltage can lead to the Error Code P0811. To find out whether the clutch is working properly within the set parameters for maximum allowable slippage, the PCM uses voltage input signals from different sensors, namely the transmission input speed sensor and the transmission output speed sensor, as well as the position of the clutch pedal.
In cases where the friction material on the clutch disc is worn down below a certain level, the clutch will start to slip. Usually, this will result in a distinctive odor or burnt friction material.
If the PCM sees a degree of transmission (clutch) slippage is more than the maximum allowable parameters, then it will set the error code and simultaneously activate the Check Engine light.
- Harsh gear engagement
- Transmission slippage
- Clutch engagement occurs near the top
- Strong odor from burnt friction material
- Defective CPPS sensor
- Damaged/worn clutch disc or pressure plate
- Shorted wiring for input speed sensor/output speed sensors
- Defective input/output speed sensor
- Defective or programming error in the PCM
How to Check
Before starting your diagnosis for this error code, make sure the clutch, pressure plate, and the throwout bearing are working properly. If possible, you also need to inspect the clutch arms, bushings, and clutch hydraulics.
You will need a diagnostic scanner, DVOM (digital volt/ohmmeter), and a source of vehicle diagnostic information. An oscilloscope can also help in diagnosing the malfunctions in the input and output speed sensor.
Use the vehicle’s information to find the TSB (technical service bulletin) that matches the specifics of the vehicle (make, model, engine size, symptoms, and codes stored). This could really help for a more thorough diagnosis.
With clutch properly working, you can proceed with the next step of the diagnosis.
Use the scanner (connected to the vehicle diagnostic connector) to retrieve all stored codes and pertinent freeze frame data. It is a good idea to write this information down before clearing the codes then test-drive the vehicle until the PCM either enters readiness mode *or the code is reset.
If the PCM enters readiness mode at this time, the code is intermittent and may be much more difficult to diagnose. If this is the case, the conditions which contributed to the code being stored may need to worsen before an accurate diagnosis can be made.
If the code is immediately reset, the next step of your diagnosis will require that you search your vehicle information source for diagnostic flow-charts, connector pin-out charts, connector face views, and component testing procedures/specifications.
Use the DVOM to test voltage, ground, and signal at the transmission input and output speed sensors (key on and engine off). Input and output speed sensor circuits typically consist of a reference voltage, a signal wire, and a ground.
Use the oscilloscope (connected to the signal circuit and ground) to check for spikes and glitches in the speed sensor signal pattern.
Most transmission slippage codes are caused by excessively worn clutch components.
How to Fix
- Replacement of the CPPS sensor
- Replacement of the clutch disc or pressure plate
- Repair corroded, disconnected, or frayed electrical connectors or wirings
- Replacement of clutch position sensor
- Replacement of PCM (rare)
This error code indicates a serious electrical problem or some type of clutch failure. This is considered a serious problem and must be addressed as soon as possible.