P0765: Shift Solenoid ‘C’ DTC Trouble Code

A shift solenoid is a small plunger device that the computer uses to actuate shifts by controlling fluid flow through the valve body. If there is a problem with one of the solenoids, a P0765 diagnostic trouble code will get stored in the ECU memory.

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What Transmission Do I Have?

How Serious is the Code?

Although the symptoms of a P0765 DTC may not appear too bad at first, they will increase the point that the vehicle cannot be driven safely.

Symptoms

Symptoms of a P0765 include:

• Check engine light
• Limp mode
• Erratic or hard shifts
• Slipping out of gear
• Engine stalling
• Transmission won’t shift out of a gear
• Vehicle won’t move when in gear
• Higher fuel consumption
• Transmission overheats

Causes

• Gearbox too low on transmission fluid
• Transmission fluid is dirty
• Wiring and/or connectors are damaged
• Transmission pump is malfunctioning
• Failing solenoid
• Hydraulic pressure problems
• Valve body problems
• ECU/TCM malfunctioning

How to Diagnose the Code?

Because an OBD2 trouble code referring to shift solenoids, relates to pressure issues. The level and quality of transmission fluid needs to be considered when starting to diagnose a solenoid diagnostic trouble code. Dirty ATF is often a sign of internal problems, which may require a replacement transmission. Performing a transmission flush can sometimes provide a temporary fix. But if major damage to the transmission pump, valve body or torque convertor has already happened, it might not make any difference.

If there are no issues with the condition of the transmission fluid, then the wiring and connectors will need to be inspected before testing the solenoid directly. If testing finds no fault with the solenoid, then the valve body and transmission pump should be considered.

Common Mistakes When Diagnosing

Many times, the shift solenoid could be blamed for the fault, when it could actually be dirty transmission fluid, or a clogged hydraulic passage. The solenoid may also need to be tested in a specific way, like while the engine is running, or in a particular gear. Failure to follow the correct procedures could cause the solenoid to appear faulty when it actually isn’t.

What Repairs Will Fix P0765?

• Changing the transmission fluid and filter
• Replace faulty solenoid
• Repair or replace a faulty transmission pump
• Repair or replace defective transmission valve body
• Perform transmission flush to clean passages
• Cleaning corrosion from connectors
• Repairing or replacing wiring
• Flash or replace PCM/TCM
• Install a rebuilt or remanufactured transmission

Related Codes

P0766 – Shift Solenoid ‘D’ Performance or Stuck Off

P0767 – Shift Solenoid ‘D’ Stuck On

P0768 – Shift Solenoid ‘D’ Electrical

P0769 – Shift Solenoid ‘D’ Intermittent

Need a replacement transmission? Get an estimate for replacement transmissions and local installation. Look up your transmission model by vehicle make and model.

What Transmission Do I Have?

Full Transmission DTC Codes Table