P2B60: coolant valve position fails to follow a settled request

P2B60 is a position-tracking diagnosis in the cited GM calibration. It compares desired and measured engine coolant flow control valve position and fails when their absolute difference exceeds 12%. Because the error is absolute, either side of the target can fail; the code does not by itself say the valve is too open or too closed.

The request must have settled

The monitor qualifies the rate of desired-position change and requires it to remain within its listed range for more than 2.5 seconds. Closed-loop position control must be active. These conditions prevent an ordinary transient during a rapidly changing request from being treated as the same evidence as persistent tracking error.

The decision uses 160 failing observations out of 200 samples at a 6.25-millisecond rate. It also requires relay voltage above 11 volts, no cranking and qualified temperature information. The continuation includes a delay after an anti-sticking event, further tying evaluation to the actuator's control state.

Compare command, feedback and enablement

A useful diagnostic record includes both requested and measured position, the size and direction of their difference, and whether the request had stabilized. Sensor range/communication faults or motor-drive faults affect how confidently a tracking error can be assigned to the mechanical valve.

The code is not proof that the position sensor alone is defective despite the generic title. Verification should demonstrate the valve reaching and maintaining several applicable settled requests with a running monitor. A single matching position while control is inactive does not exercise the documented failure mechanism.

Source and applicability

Documented 2025 GM gm-2025-04b monitor only; vehicle, engine and controller applicability must be established separately. GM monitor table, PDF page 857; GM monitor table, PDF page 858.