HomeTrouble CodesP0659

P0659 — Actuator Supply Voltage Circuit High

Generic OBD-II · all makesPowertrain (engine & transmission)

P0659 indicates the control module has detected voltage in an actuator supply circuit that exceeds the normal operating range. This suggests a short to power or a malfunctioning component drawing excessive voltage. It often affects transmission shifting or throttle response depending on the vehicle design.

Symptoms

What causes it — most likely first

1. Wiring harness shorted to power source

Damaged insulation allowing battery voltage to enter the control circuit is the most common cause.

2. Corroded or loose electrical connectors

Poor contact within the actuator circuit plugs can cause voltage spikes or irregular readings.

3. Failed actuator component

Internal shorts within the throttle body or transmission solenoid can pull voltage high.

4. Poor ground connection

A faulty ground path for the control module can cause voltage reference errors.

5. Blown fuse or faulty relay

Issues in the power supply network may disrupt voltage regulation to the actuators.

6. Faulty Powertrain Control Module

Internal processor failure is rare and should only be considered after all external circuits are verified.

How it's diagnosed

  1. Scan for all stored codes and review freeze frame data
  2. Visually inspect wiring harness for chafing, burns, or shorts
  3. Check connector pins for corrosion, bending, or looseness
  4. Measure circuit voltage with a multimeter against specifications
  5. Test resistance of associated actuators and ground points
  6. Clear codes and test drive to verify repair

Code facts & related codes

SystemPowertrain (engine & transmission)
StandardizationSAE generic — identical on every make

Frequently asked

Does this code mean I need a new computer?

No, PCM failure is rare; wiring or actuator faults are far more common causes for this code.

Can I drive with this code?

It is not recommended, as the vehicle may enter limp mode or shift harshly, risking further damage.

What happens if I ignore this code?

Continued driving may damage the transmission or throttle system due to incorrect voltage supply.

Is this a generic code?

Yes, but specific testing procedures and circuit locations vary significantly by manufacturer.