Replace any faulty, damaged, or loose wiring, connectors, or components.Replace the hydraulic pump if it is found to be bad.To fix a P0772 trouble code, the mechanic should perform the following repairs: Vehicle owners also have to be concerned with the decreased fuel mileage that this code can cause. The seriousness of a P0772 trouble code ranges from not serious at all to the total failure of the transmission to shift into any particular gear. This leads to the replacement of the shift solenoid which doesn't fix the problem, leading to the return of the code. If everything checks out and the code persists, check the PCM for fault.Ĭlear the code and test the system to see if the P0772 trouble code or others return.Ĭommon mistakes when diagnosing the P0772 codeĪ common mistake made by many mechanics when diagnosing this trouble code is to assume the code is caused by a faulty shift solenoid circuit. Make sure to disconnect any related modules, otherwise damage and memory loss can occur. If either the voltage or ground are open, check the continuity and resistance in all related circuits. If the code returns upon testing the system, hook up the manual pressure pump to the transmission, and using the hydraulic pressure diagram get an accurate reading of the pressure of the transmission's hydraulic pump, comparing the readings gained to the manufacturer's specifications.Ĭlear the code and if it returns, and check for the reference voltage and ground signal of the shift solenoid using the digital volt/ohmmeter. The mechanic should do this by starting the vehicle and allowing it to reach a normal operating temperature. The mechanic should then clear the codes before testing the vehicle to system to see if the any of the codes return. The mechanic should also examine the wiring, connectors, and related components for damage.īefore clearing the codes, the mechanic should fill the transmission fluid to a normal level and download any stored codes and freeze frame data for additional analysis if needed. The mechanic should also repair any leaks by filling the transmission to a level sufficient to fix them. If the mechanic finds any debris, the transmission must be rebuilt. To further check the condition of the transmission, remove the transmission pan and inspect it for any debris. If the fluid looks abnormal or smells burned, the mechanic might have to rebuild the transmission. Start off by pulling the transmission dipstick to examine the transmission fluid. The mechanic must also perform the following diagnostic steps: Properly diagnosing a P0772 trouble code requires a mechanic to have an OBD-II scanning tool, a digital volt/ohmmeter, a hydraulic pressure diagram, and a manual pressure pump. How does a mechanic diagnose the P0772 code? Other symptoms include no obvious symptoms other than an illuminated Check Engine Light and a stored code, overheating of the transmission, and a decrease in the vehicle's fuel efficiency. Harsh shifting, transmission slippage, or total failure to shift into any particular gear are common signs of a P0772 trouble code. Dirty or contaminated transmission fluid.Faulty PCM or Transmission Control Module (TCM).Blockage within the internal fluid passages of the transmission.Some of the common causes of a P0772 trouble code include: Mechanics should keep in mind that multiple failure cycles might be required on some models before the Check Engine Light illuminates. The particular gear ratio desired is affected by such factors as vehicle speed, engine speed, and throttle position. When there is a discrepancy between the gear ratio desired and the actual gear ratio achieved, the PCM stores a P0772 trouble code and the Check Engine Light is illuminated. Associated trouble codes include P0770, P0771, P0773, and P0774. The shift solenoids help to manage the transfer of transmission fluid between the various hydraulic circuits, which in turn cause the transmission to go into different gears. When the Powertrain Control Module (PCM) detects a problems in the shift solenoid, usually in the form of an incorrect gear ratio, a P0772 trouble code is stored.
0 Comments
Leave a Reply. |