P2718: Solenoid D control circuit has an open electrical path

P2718 is an electrical open-circuit diagnosis for pressure-control solenoid D in the reviewed GM transmission table. The source maps this monitor to different clutches in different transmissions: 9-speed C4, 10-speed C23467810R, 8-speed C23468, or the CVT input clutch.

Identify the transmission before identifying the circuit

Those mappings are alternatives, not evidence that one clutch name applies to every vehicle. The correct transmission and solenoid mapping must be established before a wiring diagram or service test is selected.

The controller judges voltage against its accepted electrical range. Its open-circuit design specification is impedance above 200 kilohms between signal and controller ground. The diagnostic needs more than 0.30 second of failure in a sample interval exceeding 0.50 second, with a 6.25-millisecond update rate.

Power state changes whether the test is valid

Battery voltage must remain above 9 V and below 32 V for more than one second. The applicable run/crank, accessory or accessory-power-mode condition must be present, and the high-side driver assigned to the solenoid must be on.

A disabled supply driver or an unmatched transmission variant can make an otherwise reasonable electrical observation irrelevant to this monitor. The impedance number is a controller specification, not an instruction to resistance-test a live circuit.

Verification should establish an intact applicable circuit and completion of the enabled check. P2718 does not directly prove a hydraulic clutch failure or require solenoid replacement. Type A, one-trip behavior is documented.

Source and applicability

These limits describe the stated monitor and require vehicle, hardware and calibration confirmation. GM diagnostic table, PDF page 1173.