P0615: starter relay open-circuit checking occurs with the driver off

P0615 is the starter relay control open-circuit monitor in these GM examples. The controller evaluates the low-side relay driver while that output is off. It compares a measured voltage against its own circuit thresholds rather than measuring starter-motor speed or delivered cranking torque.

What the table actually specifies

The controller's open-circuit detection is designed around an impedance of at least 200 kilohms between the signal and controller ground. This is a detection specification, not an instruction to measure resistance on an energized starter circuit. The published voltage thresholds themselves are controller specific.

The enable conditions include run/crank voltage of at least 11 volts. The decision uses forty failed samples out of fifty at fifty milliseconds per sample. A low-supply no-crank event may therefore fall outside this monitor's documented enable condition even if another starting fault is present.

Connect the code to the right observation

A starting complaint and P0615 are related evidence, but this row does not prove the starter motor has failed. Determine whether the relay command was off when the circuit diagnostic accumulated and whether the required voltage was available. That distinguishes the electrical detection context from the driver's request to crank.

Verification should establish a passing off-state relay-driver check under the proper conditions, as well as the vehicle's prescribed starting-system verification. Do not bypass the relay to test the code's theory; use the exact vehicle's controlled service procedure.

Source and applicability

Documented monitors in gm-2025-03a, gm-2025-04b, model year 2025. These are module/calibration examples; vehicle, engine and transmission applicability must be confirmed independently. GM 2025-03a, page 403. GM 2025-04b, page 618.