P2729: Solenoid E control circuit has a ground-short signature

P2729 is the circuit-low diagnosis for pressure-control solenoid E in the reviewed GM transmission table. The monitor evaluates electrical voltage behavior, not hydraulic pressure measured at a clutch.

Four mappings share the diagnostic description

Depending on transmission, the source assigns this circuit to 9-speed C57R, 10-speed C1356789, 8-speed C45678R, or CVT torque-converter control. This distinction matters when comparing related hydraulic faults: the function attached to the electrical code is not universal.

A voltage outside the accepted range indicates a ground short. The controller's design criterion is less than 0.5 ohm between signal and controller ground. More than 0.30 second of failure within a sample time exceeding 0.50 second is required, updated every 6.25 milliseconds.

A powered circuit is a prerequisite

The mapped high-side driver must be on, and battery voltage must be between 9 V and 32 V for more than one second. Run/crank or accessory conditions also control availability. A signal observed while its supply is intentionally disabled does not necessarily address this check.

Use the appropriate vehicle circuit procedure to distinguish a ground path in wiring, the connected component and the output stage. The source's impedance value is not a directive to resistance-test an energized circuit.

Verification should demonstrate acceptable solenoid E electrical response through a valid monitor window. This Type A, one-trip code does not independently prove converter or clutch damage, and it does not prescribe valve-body replacement.

Source and applicability

Keep the stated transmission function and source calibration separate from other applications. GM diagnostic table, PDF page 1183.