P26E6: Starter Relay B Circuit High

P26E6 reports a short to positive on the control line of starter relay B. GM tests for it while its driver for the tandem starter pinion relay is off: if the line still shows 0.5 Ohm or less toward a power source for 40 out of 50 checks taken every 50 ms, with the engine stopped and at least 11 V available, the code is stored as type B. The danger of this fault is a relay that is energised without a command, so the pinion could be pushed into the ring gear. The diagnostic appears in GM's 2018 and 2023 tables with the same thresholds. P26E4 and P26E5 cover open and grounded circuits.

Medium severity. Can I keep driving?If it starts normally you can keep driving, but avoid stopping anywhere you could not get help, because it might not restart.

Symptoms

Check engine light
Stop-start disabled
Starter noise or grinding without a start command

Most likely causes

Relay B control wire shorted to a battery-powered wire, e.g. under the battery tray
Relay B internally fed or contacts welded
Engine module driver output not switching off

What to check, in order

Start with the simplest. You can tick off each step.

Check the battery voltage
Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
Try another key, if you have one
Check the fuses and the starter relay
Check the wiring and the signal to the starter motor

Good to know

Repair difficulty: medium
It affects emissions.

What each character of P26E6 means

P: Powertrain: engine and transmission
2: Generic code: same on every make
6: Control modules and outputs
E6: Specific fault in that system

Frequently asked questions

Can I keep driving with code P26E6?

If it starts normally you can keep driving, but avoid stopping anywhere you could not get help, because it might not restart.

What causes code P26E6?

The most common causes are: relay B control wire shorted to a battery-powered wire, e.g. under the battery tray; relay B internally fed or contacts welded; engine module driver output not switching off.

Related codes

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.