P2088: bank-one intake actuator control is low while its high-side driver is on

P2088 is bank-one intake camshaft actuator control circuit low in the cited ECM implementation. The controller checks a high-side driver supplying the cam-phaser oil-control valve and detects a ground-short signature while that output is on.

Electrical low is not cam timing retard

The row measures driver-circuit voltage, not the camshaft's angular position or how far timing follows a request. It therefore does not prove a stretched timing chain, sticking phaser or inadequate oil pressure. Those are different diagnostic questions that require separate evidence.

The detection specification is less than 0.5 ohm between the signal and controller ground, implemented through controller-specific voltage thresholds. It is not an instruction to measure resistance on a powered actuator circuit.

Match the test to the driver architecture

The monitor requires system supply above 11 volts, the output commanded on and ignition in crank or run. Twenty failed samples out of twenty-five, taken at 250 milliseconds per sample, form the documented decision. A low reading with the output off is not the same fault observation for this high-side design.

Record actuator command and electrical response together. Verification should demonstrate a passing enabled circuit-low monitor before drawing a conclusion about mechanical timing response. The cited page supports the bank-one intake mapping only for its documented strategy; it does not provide engine compatibility, a physical bank location or a mandatory solenoid replacement.

Source and applicability

Documented monitors in gm-2025-03a, model year 2025. These are module/calibration examples; vehicle, engine and transmission applicability must be confirmed independently. GM 2025-03a, page 584.