Powertrain, generic (extended)

P26F2 Starter Relay B Stuck On

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P26F2 concerns the second starter relay, which on stop-start vehicles may engage the pinion of a tandem starter (GM) or form the second switching path of a two-relay layout (FCA Starter Control 2). The code means relay B fails to drop out after its command ends. Depending on wiring, the pinion may then remain in mesh, or the starter could be energised as soon as relay A closes. No manufacturer documents P26F2 publicly; the GM tables only cover the electrical driver faults of relay B (P26E4 to P26E6), and FCA bulletins tie Starter Control 2 to plausibility faults. Welded contacts and a control line fed from elsewhere are the obvious suspects. Driving on with this fault risks damage to the pinion and the flywheel ring gear.

Likely causes

Contacts of relay B welded or stuck
Control line of relay B fed from another circuit
Pinion solenoid of the tandem starter sticking mechanically

Symptoms

  • Grinding or whining from the starter after the engine runs
  • Check engine light, stop-start unavailable

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€30–800
Time0.3–3 h

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

Parts involved

starter relay bstarter motor b

Related codes

P26F3P26F0P26E4P26E6

References: law.cornell.edu, gsi.ext.gm.com, static.nhtsa.gov.