P208D: pump short-to-power is isolated after the pump is stopped

P208D concerns a high-voltage electrical condition in one of the three reductant pump motor phases. The reviewed GM strategy explicitly separates initial fault detection while the pump is running from identification of the specific failure after the pump is switched off.

Running detection is not final classification

In the on-line state, missing expected back-EMF detection at 60-degree intervals causes the pump to transition off-line. The table states that the precise fault cannot be pinpointed in the pump-on state. Once off-line, an internal driver status identifies a circuit-high condition due to a short to power.

This makes an automatic pump stop part of the diagnostic sequence. It should not automatically be interpreted as proof of a seized pump or a lost external supply. The fault direction comes from the subsequent off-line hardware result.

Qualification and recovery

The vehicle must be in an active power mode, and specified controller-internal faults must be absent. Forty failing samples at 0.01 second each provide a 0.4-second qualification. Reporting is Type A over one trip; recovery is listed only for the next driving cycle.

Verification should establish that the off-line circuit check no longer reports the power-short condition and that the applicable next-cycle assessment completes. Observing rotation alone does not prove that diagnostic result. The source identifies neither the affected phase nor a replacement component. These criteria are limited to the documented 2025 GM pump-control implementation and require the vehicle's service procedure for electrical isolation.

Source: GM monitor, PDF page 194.