P073E: reverse selection fails the range-agreement check

In the reviewed GM implementation, P073E is a range-selection supervision code. Reverse is commanded, but the actual arbitrated transmission range does not become Reverse within the allowed shift period. The monitor does not by itself identify a reverse clutch, actuator or wiring failure.

Timing is part of the definition

The failure timer increases while actual range differs from Reverse. It must reach the expected shift time before the diagnostic qualifies. GM does not give a universal numerical shift duration on this page, so any claim that this code always sets after a particular number of seconds would exceed the evidence.

Actual-range information must be classified as good for this comparison. That is diagnostically useful: disagreement with a trusted range value should be distinguished from a range-signal validity fault. A scan trace needs both the value and its status, not merely the driver's selector position.

Evaluating the result

The code-clear function and manufacturing mode must be inactive. The power-state conditions include Run/Crank or accessory/wakeup, with an internal active period continuing until Park is attained and accessory/wakeup ends. The row lists Type B, two-trip reporting.

Verification requires watching the requested Reverse transition through the permitted interval and confirming the resulting actual range. Absence of a code during an inhibited power state does not establish successful engagement. Because range engagement affects vehicle movement, functional checks require the applicable controlled service procedure. The table provides a monitor explanation, not a repair instruction or a definitive model/engine application list.

Source: GM monitor, PDF page 645.