P2721 Pressure Control Solenoid D Control Circuit High

Description and meaning of DTC p2721

This is a generic transmission diagnostic trouble code (DTC) and applies to OBD-II vehicles with an automatic transmission. That may include but is not limited to vehicles from Ford, GMC, Chevrolet, Honda, BMW, Saturn, Land Rover, Acura, Nissan, Saturn, etc. Although generic, the exact repair steps may vary depending on year, make, model and powertrain configuration. In most circumstances automatic transmissions will incorporate at least three pressure control solenoids know as solenoid A, B and C. Newer transmissions tend to have more gears and more solenoids, giving you solenoids D, E, F, etc. Various trouble codes are associated to the D solenoid control circuit and some of the most common include P2718, P2719, P2720, and P2721. When the P2721 OBD-II trouble code is set, the Powertrain Control Module (PCM) has detected a problem with the transmission pressure control solenoid D control circuit.   The specific code set is based on the specific malfunction that is detected by the PCM. An automatic transmission is controlled by bands and clutches that change gears by having fluid pressure in the right place at the right time. The purpose of the transmission pressure control solenoids is to adjust the pressure of the fluid for the automatic transmission to operate properly and shift smoothly. The PCM monitors the pressure within the solenoids and directs fluid to various hydraulic circuits that change the transmission gear ratio precisely as needed. Code P2721 is set by the PCM when it detects that the pressure control solenoid D control circuit is experiencing a high voltage condition and therefore is not functioning properly.

p2721 diagnostic trouble code symptoms

Symptoms of a P2721 trouble code may include:Increased fuel consumptionCheck Engine Light activatedTransmission overheatsTransmission slips when shiftingTransmission shifts hard (banging into gear)Possibly misfire-like symptoms The transmission is put into limp mode by the PCM

DTC p2721 - possible causes

Causes for this P2721 transmission code may include:Defective pressure control solenoidContaminated transmission fluidRestricted transmission filterDefective transmission pumpDefective transmission valve body Blocked hydraulic passagesCorroded or damaged connectorFaulty or damaged wiringFaulty PCM

How to fix OBD-II diagnostic trouble code p2721

Prior to beginning the troubleshooting process for any malfunction you should research the Technical Service Bulletins (TSB's) for the specific vehicle by year, model and transmission. In some situations this can save a lot of time in the long run by pointing you in the right direction. Fluid Wiring InspectionsThe first step is to check the fluid level and examine the condition of the fluid for contamination. Prior to changing the fluid, you should (if possible) check the vehicle records to verify the last time that the filter and fluid was changed. A detailed visual inspection to check the condition of the wiring for obvious defects is next. Check the connectors and connections for security, corrosion and damaged pins. This should include all wiring and connectors to the transmission pressure control solenoids, the transmission pump and the PCM. Based on the specific configuration, the transmission pump may be driven electrically or mechanically. Advanced StepsThe advanced steps always become very vehicle specific and require the appropriate advanced equipment to perform accurately. These procedures require a digital multi meter and the specific technical references for the vehicle. You should always obtain the specific troubleshooting data for your vehicle prior to proceeding with the advanced steps. Voltage requirements will vary based on the specific model of the vehicle. Fluid pressure requirements may also vary based on the transmission design and configuration. Continuity ChecksUnless otherwise specified by the technical data, the normal readings for wiring and connections should be 0 ohms of resistance. Continuity checks should always be performed with the power removed from the circuit to avoid shorting the circuit and creating more damage. Resistance or no continuity is an indication of faulty wiring that is open or shorted and must be repaired or replaced.

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