Chart C-1 Vehicle Will Not Enter Diagnostics

You have been sent to this chart due to the following symptoms: 1) The odometer displays correct mileage (Digital Cluster"), or the voltmeter indicates correct system voltage (Analog Cluster). 2) The Computer Control Driver Information Center (CCDIC) (and Digital IPC) displays work. 3) The "Engine Control System Fault" telltale lights at crank. 4) Pressing "OFF" and "Warmer buttons does not result in diagnostic mode.

Notes on trouble trees
1. This checks for operation of the "OFF" (and other) climate control buttons. If the "OFF" (or other) buttons do not respond go to chart C-2. Chart C-2
2. This checks for operation of the "Warmer" (red) button.
3. If both the Off and Warmer buttons work one at a time and diagnostics is still not entered, replace the CCDIC (combo panel).