Central Control Module (CCM)

Circuit Description

The LCD Data Circuit carries the actual 160-bit data stream that contains the desired states of all segments on the LCD panel.

On power-up, the CCM pulls CKT 1365 low. After 80 milliseconds, it is sent high. If it is still low 40 milliseconds later, Code 32 will set.

Test Description

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

1. This test checks for a short to ground in the circuit.
2. This test checks for an open in the circuit.
3. This test replaces the cluster with a 1200 ohm resistance, very similar to the resistance of the cluster. If the code comes back, the CCM must be at fault. If the code does not come back, the cluster, must be the source of the problem.

Diagnostic Aids

If there is a short to ground, all segments of the LCD digits will be "ON"; if there is an open, the LCD display will be blank.

If the code is a history code, the problem may be intermittent. Try performing the tests shown while "wiggling" wiring and connectors; this can often cause the fault to appear. Refer to "Intermittents/Poor Connections".