FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.

Computed Timing Check Description

The computed timing check verifies that the Powertrain Control Module (PCM) is controlling the spark advance.
The test is performed by STARTING the engine with the SPOUT connector disconnected, checking the base timing, installing the SPOUT connector with the engine running, and checking for timing advance.