Powertrain, generic (extended)

P26E8 Actuator Supply Voltage D Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P26E8 says the voltage on supply rail D drops too far while the rail is switched on. In GM's 2023 and 2024 TCM tables this is watched continuously at high-side output 8: a timer runs when the voltage falls below a share of the supply or the averaged current is too high, and after 60 ms the code is set, Type A; it is suspended while P0882 or P0883 is present. Ford's 2024 table lists P26E8 as the shorted-load fault of driver 8 in the TR9070 dual-clutch unit. On Volvo and Mack trucks of the US13 generation the aftertreatment module uses this rail to feed both NOx sensors upstream and downstream of the SCR, the particulate sensor plus the DEF quality sender; bulletins K31280406 and KC-415 describe brief dips when all four draw peak power, with communication codes for these sensors and a possible derate warning.

Likely causes

Supply line or a connected load shorted to ground
Loose or corroded battery, fuse or ground connections feeding the module, or weak batteries (Volvo/Mack aftertreatment module)
Faulty sensor or solenoid on the rail drawing too much current
Internal fault in the module output stage

Symptoms

  • Warning light on, often only briefly or intermittently
  • Transmission failsafe mode with loss of the solenoids on that rail
  • On trucks, lost communication with NOx, PM and DEF sensors and a derate warning

Repair estimate

DifficultyHardWorkshop job
Parts and labour€80–1,500
Time1–5 h

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

Parts involved

actuator supply dcontrol modulewiring harness

Related codes

P26E7P26E9P2685P2670P0658

References: gsi.ext.gm.com, fordservicecontent.com, static.nhtsa.gov, static.nhtsa.gov.