P045D: low-pressure EGR command short toward the power supply

The P045D monitor checks low-pressure EGR commands for a short to the power supply. In the cited table, the hardware detects that category while H-bridge switch current exceeds 8 A during an on command.

Read the category with the current

The word “high” does not identify excessive EGR flow or a valve angle. It labels an electrical control-circuit fault. Because P045C's ground-short row shares the 8 A threshold, an overcurrent trace without hardware classification cannot by itself distinguish those two fault types.

Monitoring requires relay supply above 11 V, no cranking, enabled diagnostics and a hardware status other than indeterminate. The filter is 240 failures among 300 samples at a 12.5 ms function interval, with Type A, one-trip reporting.

Evidence for confirmation

Record whether the driver was on when the fault occurred and whether the supply prerequisite was met. An off-state check may be useful under a service procedure, but it is not the operating state used by this current monitor.

A successful verification addresses normal response during an eligible driven period and the underlying electrical path. The summary cannot locate the short or choose between harness, actuator and controller repair. Use the vehicle-specific circuit procedure; do not apply external power or create a short merely to reproduce the listed hardware condition.

Source and applicability

2025 GM 25OBDG04B diagnostic parameter tables; the cited monitor only. Vehicle, engine and calibration applicability must be confirmed separately. These tables describe detection logic, not a complete repair procedure or a component replacement verdict. gm-2025-04b, PDF page 1193.