Diagnostic Aids

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2008 GMC Yukon XL, 2008 GMC Yukon, 2008 Chevrolet Tahoe, 2008 Chevrolet Suburban, and 2008 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

The VLOM solenoids are assigned to the following engine cylinders:

Solenoid #1 = Cylinder #1
Solenoid #2 = Cylinder #4
Solenoid #3 = Cylinder #6
Solenoid #4 = Cylinder #7

IMPORTANT: This test procedure requires that the vehicle battery has passed a load test and is completely charged. Refer to Battery Inspection/Test .

Remove and inspect the fuse for the valve lifter oil manifold assembly.
- If the fuse is open, then a short to ground condition exists in the circuit.
Ignition ON, engine OFF, measure and record the ignition voltage at the fuse for the valve lifter oil manifold (VOLM) assembly.
Connect a DMM in series with a 15A fused jumper wire and a non-fused jumper wire across the exposed fuse terminals in the underhood fuse block.
Select the 10A range and zero out the DMM display.
Command each VLOM solenoid ON with a scan tool.
Record the amperage reading display on the DMM for each solenoid.
- If zero current is detected, then an open circuit condition exists in the circuit.
Calculate the resistance for each solenoid circuit. The total resistance for each solenoid circuit should be within 11-22 ohms.
- If the total circuit resistance exceeds 22 ohms, an open/high resistance condition exists in the circuit.