P02E1: diesel throttle cannot track its requested position

The documented P02E1 monitor compares diesel throttle position with its requested position. An absolute tracking error greater than 10% is the failure criterion, intended to detect obstruction during opening or closing.

Position error needs valid operating conditions

The monitor is enabled outside cranking, with powertrain-relay voltage above 11 V, cold-start strategy inactive and valid temperature inputs. Coolant must be at least 40°C or the cooling-system target must have been reached; outside air must be at least −20°C.

The following page adds a steady-setpoint requirement: rate of change between −100 and 100% per second for at least 0.30 second. Mechanical-stop soft approach and anti-sticking operation must not be underway. Consequently, a large difference captured during a deliberate transient is not automatically the same evidence as this diagnostic.

Separate obstruction from electrical explanation

The listed filter uses 960 failures among 1,200 samples on a 6.25 ms task. After 480 failure counts, the strategy enables the P02E0 open-circuit check. That relationship makes accompanying open-load evidence particularly useful before deciding that the valve is mechanically jammed.

Verification should compare stable requested and measured position with closed-loop control active and valid position feedback. A performance code alone does not identify deposits, a damaged motor or a specific replacement. The source documents the monitor's discrimination, not a cleaning or repair procedure.

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 1162; gm-2025-04b, PDF page 1163.