Technical Description of OBD-II Trouble Code
Shift Time Exceeds Limit
What does that signify?
This diagnostic trouble code (DTC) is a generic powertrain code that is applicable to many OBD-II vehicles (1996-newer). This includes vehicles from Volvo, Mercedes Benz, Ford, Dodge, BMW, Land Rover, Citroen, Peugeot, etc. While it is a generic code, the specific repair steps may vary depending on the 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 indicating that the time interval for shifting between gears is too long.
The transmission control module (TCM) may be a separate unit, but it is commonly integrated into a single housing with the engine control module (ECM). This combined unit is known as the PCM.
The PCM uses input signals from various engine and transmission sensors to calculate the automatic transmission shift strategy. A high-pressure pump inside the transmission forces fluid through the valve body and into the sprag assembly, which lubricates and cools the transmission. The high-pressure fluid allows the clutches to momentarily separate from the sprag, enabling smooth gear ratio changes. Electronic pressure control (EPC) solenoids help regulate fluid pressure, while electronic pressure (EP) sensors provide the PCM with data on fluid pressure at different points in the transmission. Electronic shift solenoids interrupt the flow of high-pressure fluid to facilitate gear shifts 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.
Similar to other automatic transmission malfunctions, a transmission shift time code can be caused by electrical or mechanical failures. If the PCM detects excessive shift time, it will store a code P0896 and illuminate the malfunction indicator lamp (MIL).
What is the severity of this DTC?
A stored code P0896 indicates a significant shifting problem. It is crucial to rectify the conditions that led to this code being stored as quickly as possible.
What are some of the symptoms of the code?
Symptoms of a P0896 trouble code may include:
What are some of the common causes of the code?
Possible causes for this code may include:
What are some P0896 troubleshooting steps?
When diagnosing automatic transmission codes, start by ensuring that the transmission fluid is clean and at the appropriate level. If the fluid level is low, locate and repair the source of the leak. Refill the transmission with the recommended fluid and proceed.
If the fluid is excessively dark and has a strong burnt friction material odor, it needs to be replaced. This can be done by removing the transmission pan (and draining the torque converter) or by flushing the transmission (recommended). In either case, the filter should also be replaced. When removing the pan, be careful to preserve any debris that may have accumulated. If the pan is relatively clear of debris, it indicates that the clutches are mechanically intact. If there is a significant amount of friction material in the pan (and stuck to the magnet), the transmission will require a rebuild by a qualified technician.
Diagnosing a code P0896 requires a diagnostic scanner, a digital volt/ohmmeter (DVOM), and vehicle-specific diagnostic information. Testing the actual transmission pump (fluid) pressure requires a manual transmission fluid pressure gauge.
Refer to your vehicle information source to find a technical service bulletin (TSB) that matches the vehicle’s year, make, and model, as well as the engine size, stored codes, and exhibited symptoms. If a relevant TSB is found, it can provide helpful diagnostic information.
With the transmission filled to the appropriate level with the recommended fluid, proceed with the first step of the diagnosis.
Step 1
Use the manual pressure gauge to test the transmission fluid pressure at the specified opening on the transmission. If the transmission fluid pressure is not within the recommended specifications, the pump may need to be rebuilt or replaced. A transmission rebuild is typically necessary in this case. If the fluid pressure is within specs, proceed to Step 2.
Step 2
Use the scanner connected to the vehicle diagnostic connector to retrieve all stored codes and relevant freeze frame data. It is advisable to write down this information before clearing the codes and 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 more challenging to diagnose. In such cases, the conditions that led to the code being stored may need to worsen before an accurate diagnosis can be made.
Step 3
If the code is immediately reset, the next step in the diagnosis involves searching the vehicle information source for diagnostic flowcharts, connector pin-out charts, connector face views, and component testing procedures/specifications.
Step 4
Use the DVOM to test the voltage and ground circuits at the EPC solenoid and EP sensors. If voltage and ground are detected, test the EPC solenoid and EP sensors. Any components that fail to meet the recommended specifications should be considered defective. If the components are functional, test the signal circuit that inputs to the PCM.
Step 5
If the EPC solenoids and EP sensors are functional, and the signal input is present, use the DVOM to test the system circuits. The voltage drop testing method is effective for this task. Disconnect all controllers from the circuit before testing resistance with the DVOM.
Professional Service
We always recommend seeking professional mechanical assistance to resolve this issue. However, if that is not possible, we offer the option to permanently delete this specific DTC while keeping all other codes active. If you are interested in this service, please upload your ECU file to our portal.