Control Solenoid Valve and Transmission Control Module Assembly Output Shaft Speed Input Test: Procedure

WARNING: This page is about a different car, the 2008 GMC Yukon and 2008 Chevrolet Tahoe. However, it is still accessible from the selected car via links, so may be relevant.

Disconnect the OSS wiring harness connector from the OSS assembly.
Using a terminal test kit, connect the red lead of J 38522 to the OSS signal circuit terminal B and the black lead to the OSS supply voltage circuit terminal A.
1. Set the J 38522 Signal to 8 volts, the Frequency to 120 and the Percent Duty Cycle to 50.
2. With the ignition ON, observe the scan tool parameter OSS Signal.
3. The signal parameter should display between 100-400 RPM.

If the signal display is not in this range, test the OSS signal and supply voltage circuits for an open/high resistance, short to ground, or short to voltage. If the circuits test normal, the control solenoid (w/body and TCM) valve assembly is not reading the input signal correctly and is faulty.