Powertrain, generic (extended)

P26E5 Starter Relay B Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P26E5 indicates that the control circuit of starter relay B is shorted against ground. GM documents it for the tandem starter pinion relay of its 12 V stop-start engines: while the driver is switched on, an impedance of 0.5 Ohm or less toward ground in 8 of 10 samples of 50 ms sets the code, enabled at standstill once run/crank voltage is at least 6.41 V; the lamp follows as type B after two trips. The same entries appear in GM's 2019 tables for the 5.3 litre V8 and in 2023 tables. A GM preliminary information for 2019 to 2021 Silverado and Sierra 1500 with the 2.7 litre engine lists P26E5 among many codes caused by a shorting engine harness and blown fuses. Open and high-voltage faults are P26E4 and P26E6.

Likely causes

Engine harness chafed so the relay B control wire touches ground
Shorted coil in relay B or the pinion solenoid
Damaged high-side driver in the engine module

Symptoms

  • Check engine light
  • No crank or no restart after an automatic engine stop
  • Blown fuses and further unrelated codes if a harness short is the cause

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–800
Time0.5–4 h

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

Parts involved

starter relay bwiring harness

Related codes

P26E4P26E6P0616P26F3

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