P2598: Turbo position remains low relative to its command

P2598 concerns a turbocharger boost-control position that appears stuck low relative to its command. In the cited GM monitor, the controller compares desired and actual vane position and calculates a control deviation. The listed failure boundary is a positive deviation greater than 10%, sustained for ten seconds.

An in-range error is different from low voltage

The source explicitly describes this as an in-range position fault. On the same page, P2564 separately detects a sensor voltage below 0.23 V. A believable electrical signal can therefore coexist with P2598 if the position does not match the request; “stuck low” does not automatically mean a short to ground.

The adjacent P2599 branch uses a negative deviation below −10% for the opposite directional performance finding. Keeping desired position, actual position and the controller's deviation convention together is more useful than interpreting one feedback percentage in isolation.

Account for the qualified monitor state

The table requires an operating engine and evaluates the monitor at a 0.02-second rate. Its continuing enable list includes learned-offset and temperature conditions. Some state labels use negative wording, including “valve not jammed = FALSE,” so this summary should not be treated as a complete, self-explanatory workshop test sequence.

A useful verification establishes that the appropriate position comparison actually ran and no longer accumulated the sustained error. It does not infer turbocharger replacement from the code alone. Vehicle-specific diagnosis must distinguish feedback, actuation and mechanical response; this historical source supplies no universal actuator travel specification or safe manual movement procedure.

Source and applicability

GM 2015 15OBDG04 ECM Summary Tables, turbo position performance rows on physical pages 249–250. Negative-worded state flags need calibration-specific interpretation; no particular vehicle fitment is inferred.

General Motors source, physical page 249 · General Motors source, physical page 250