P0896 Shift Time Too Long

Description and meaning of DTC p0896

This diagnostic trouble code (DTC) is a generic powertrain code and applies to many OBD-II vehicles (1996-newer). That may include but is not limited to vehicles from Volvo, Mercedes Benz, Ford, Dodge, BMW, Land Rover, Citroen, Peugeot, etc. Although generic, the exact repair steps may vary depending on year, make, model and powertrain configuration. If your vehicle has stored a code P0896, it means that the powertrain control module (PCM) has received a data input signal from the input and output speed sensors which indicates that the interval to shift between gears is excessive. The transmission control module (TCM) may be a stand alone unit but is most commonly integrated into a single housing with the engine control module (ECM). This is called the PCM. The PCM utilizes input signals from multiple engine and transmission sensors to calculate automatic transmission shift strategy. A high pressure pump (inside the transmission) forces fluid through the valve body and into the sprag assembly in addition to lubricating and cooling the transmission. The high pressure fluid allows the clutches to separate from the sprag momentarily so that the gear ratio may be changed smoothly. One or more electronic pressure control (EPC) solenoids help to regulate fluid pressure. Electronic pressure (EP) sensors provide the PCM with pertinent data regarding fluid pressure at various points in the transmission. Electronic shift solenoids are used to interrupt the flow of high pressure fluid so that the transmission shifts gears when commanded. The PCM uses voltage input signals from the transmission input speed sensor and transmission output speed sensor to determine if the transmission is shifting efficiently. As with many other automatic transmission malfunctions, a transmission shift time code may be caused by electrical or mechanical failure. If the PCM detects that shift time is excessive, a code P0896 may be stored and a malfunction indicator lamp (MIL) illuminated.

p0896 diagnostic trouble code symptoms

Symptoms of a P0896 trouble code may include:Excessive transmission fluid pressureDelayed and/or harsh gear engagementErratic transmission shift patternsUnusual whining noise from transmission

DTC p0896 - possible causes

Causes for this code may include:Defective high pressure pump in the transmissionCatastrophic internal (mechanical) transmission failureShorted wiring for EPC solenoid or EP sensorsBad EPC solenoid or EP sensorFaulty PCM or a programming error

How to fix OBD-II diagnostic trouble code p0896

When diagnosing automatic transmission codes, you should begin by making sure that the transmission fluid is clean and that the transmission if filled to the appropriate level. If the fluid level is low, locate the source of the leak and repair the condition. Refill the transmission with the recommended fluid and proceed. If the fluid is excessively dark and smells strongly of burnt friction material, it will need to be replaced. This can be accomplished by removing the transmission pan (and draining the torque converter) or flushing the transmission (recommended). Either way, you will want to replace the filter at this time too. When removing the pan from the transmission, take care to preserve whatever debris may have landed therein. If the pan is relatively clear of debris you can assume that the clutches are mechanically intact. If there is an excessive amount of friction material in the pan (and stuck to the magnet), the transmission will require a rebuild from a qualified technician. A diagnostic scanner, a digital volt/ohmmeter (DVOM), and a source of vehicle specific diagnostic information will be required to diagnose a code P0896. A manual transmission fluid pressure gauge will be required to check actual transmission pump (fluid) pressure. You may use your source of vehicle information to locate a technical service bulletin (TSB) that matches the vehicle year, make, and model as well as the engine size, code/s stored, and symptoms exhibited. If you find one, it could yield helpful diagnostic information. With the transmission filled to the appropriate level with the recommended fluid, proceed with the first step of the diagnosis. Step 1Use the manual pressure gauge to test transmission fluid pressure at the appropriate opening on the transmission. If transmission fluid pressure is not within recommended specifications, the pump may need to be rebuilt or replaced. A transmission rebuild is generally in order if this is the case. If fluid is within specs proceed to Step 2. Step 2Use 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. Step 3If 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. Step 4Use the DVOM to test voltage and ground circuits at the EPC solenoid and EP sensors. If voltage and ground are detected, test the EPC solenoid and the EP sensors. Any components which fail to comply with recommended specifications should be considered defective. If the components are functional test the signal circuit that is input to the PCM. Step 5If EPC solenoids and EP sensors are functional, and the signal input is present, use the DVOM to test system circuits. The voltage drop testing method works well for this task. Disconnect all controllers from the circuit prior to testing resistance with the DVOM. High-mileage vehicles may experience transmission high-pressure pump failureTransmission shift time codes may be caused by a low fluid condition

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