Powertrain, generic (extended)

P2671 Actuator Supply Voltage B Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2671 points to voltage on the second actuator supply when the controller has switched it off, so the line is fed from outside or the switch inside the module no longer opens. The solenoids on that supply can then no longer be de-energised as a group, which defeats the failsafe. GM tests this mostly at start-up or shut-down: in the 16OBDG08 TCM tables a short to power below 0.5 ohm is detected during initialisation with the driver off; the 2023 TCM checks at power-down whether the supply stays above 70 % of battery voltage, stores the result and sets the code at the next start as Type B. GM's hybrid HPC1 table of 2019 likewise rates it Type B. Ford's 2014 list contains P2671 without MIL. P2669 is the open circuit, P2670 the short to ground.

Likely causes

Supply line shorted to another powered circuit
High-side switch in the controller stuck closed
Moisture or corrosion bridging pins in the transmission connector

Symptoms

  • Warning lamp after the next start
  • Often no immediate shift complaint
  • Failsafe may not engage correctly if another fault occurs

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–1,500
Time1–5 h

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

Parts involved

actuator supply bcontrol modulewiring harness

Related codes

P2669P2670P0659P2686

References: gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com, performanceparts.ford.com.