P0659 code meaning
Actuator Supply Voltage A Circuit High
Powertrain system Generic code P06xx codes Check engine light
What P0659 means
Actuator supply A is a high-side switch feeding several actuators together; its use differs by maker (Ford transmission solenoids, GM shared high-side driver, GM Europe 2.0 CDTI internal 5 V supply). P0659 means a short to voltage on the supply output, checked with the driver off – the output should then be dead (GM: 0.5 Ω or less to the supply, 20 of 25 samples; lamp after two trips in 2017–18, none in 2016). The driver can then no longer switch the actuators off; GM's transmission modules block their solenoid diagnostics while P0658/P0659 are active, and limp mode follows. On GM Europe's 2.0 CDTI it means the internal 5 V supply is too high, without MIL – the engine module is replaced.
P0659 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyHard
- Typical labor1 to 5 hours
- Clears after repairAfter a drive cycle
Symptoms of P0659
- Check engine light (GM from 2017)
- Transmission or actuator limp mode
- Actuators cannot be switched off
- Follow-up codes
Common causes of P0659
- Most likelyActuator supply wire shorted to battery or ignition voltage
- PossibleHarness chafed against a 12 V line
- PossibleModule (driver shorted; internal on the Saab diesel)
- Less likelyExternal voltage fed back through a faulty actuator
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Actuator supply circuitTransmission solenoidsControl module
What each part of P0659 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 6 | Area: computer (engine control module) and output circuits. |
| 59 | The exact fault in that area. |
What to do next
- Note P0659 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0659
What does P0659 mean?
P0659 means "Actuator Supply Voltage A Circuit High". Actuator supply A is a high-side switch feeding several actuators together; its use differs by maker (Ford transmission solenoids, GM shared high-side driver, GM Europe 2.0 CDTI internal 5 V supply). It is a generic code, so it means the same on every make.
Is it safe to drive with P0659?
Drive gently and only to a workshop. With P0659 the car can go into limp mode (reduced power) to protect itself.
Will P0659 fail an emissions test?
Yes, it can. P0659 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0659 to fix?
Difficulty: hard. A typical repair takes 1 to 5 hours of work. This is a job for a workshop.
Will P0659 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.