Powertrain, generic · Computer and auxiliary outputs

P0659 Actuator Supply Voltage A Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

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.

Likely causes

Actuator supply wire shorted to battery or ignition voltage
Harness chafed against a 12 V line
Module (driver shorted; internal on the Saab diesel)
External voltage fed back through a faulty actuator

Symptoms

  • Check engine light (GM from 2017)
  • Transmission or actuator limp mode
  • Actuators cannot be switched off
  • Follow-up codes

Repair estimate

DifficultyHardWorkshop job
Parts and labour€150–1,500
Time1–5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

actuator supply circuittransmission solenoidscontrol module

Related codes

P0657P0658P2671P2669P0643

References: law.cornell.edu, gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com.