Initial Inspection and Diagnostic Overview

CIRCUIT DESCRIPTION

The system diagnostic check is an organized approach to identify the problems associated with the Central Control Module (CCM). It must be a starting point for any CCM complaint, because it directs the service technician to the next logical step in diagnosing the complaint. The CCM itself is a very reliable component, and is not likely the cause of the malfunction. Most system malfunctions are linked to faulty wiring and connectors, and occasionally components. Understanding the chart and using it correctly will reduce diagnostic time and prevent unnecessary parts replacement.

CHART TEST DESCRIPTION

Number(s) below refer to circled number(s) on the diagnostic chart.

1. This step to determine if the Tech 1 can communicate with the Central Control Module (CCM).

2. Checks to see if diagnostics can be entered in the On-Board Diagnostic mode.

3. This checks CCM Power and ground circuits. (Refer to DIAGRAMS)

DIAGNOSTIC AIDS

If the problem is intermittent. Try performing the tests shown while "wiggling" wiring and connectors, this can often cause the malfunction to appear. Check for poor connectors at both the CCM and related components, these could cause and open, short, or an intermittent malfunction. Refer to "Intermittents and Poor Connections" in DIAGRAMS. Check CCM 1, CCM 2 and CCM 3 fuses. If CCM fuse 3 is blown the CCM will still operate normal, but a DTC 16 will be stored.