Powertrain, generic · Computer and auxiliary outputs

P0658 Actuator Supply Voltage A Circuit Low

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). P0658 means the supply output is too low with the driver on – a short to ground (0.5 Ω or less). GM's engine module checks its shared high-side driver in 20 of 25 samples; the lamp rating changed from none (2016) via two trips (2017–18) to the first trip (2025). GM's transmission modules include an open circuit here, set it in the first trip and block the solenoid diagnostics, so the gearbox goes into limp mode. On GM Europe's 2.0 CDTI it means the internal 5 V supply is too low – no MIL, and if it recurs, the engine module is replaced.

Likely causes

Actuator supply wire shorted to ground
Actuator (solenoid) shorted internally
Transmission harness or connector (also open, in transmission modules)
Module internal (main cause on the Saab diesel)

Symptoms

  • Transmission limp mode or fixed gear
  • Several actuators not working
  • Check engine light (GM from 2017)
  • Codes for individual solenoids

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

P0657P0659P2670P2669P0641

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