Central Control Module (CCM)

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

The Daytime Running Lights (DRL) function is used on Canadian vehicles only. When the CCM receives a request for DRL "ON" it grounds CKT 592 at CCM C1 connector, terminal "A3

TEST CONDITIONS

^ If the CCM is awake and is configured as a Canadian vehicle the DRL enable function of the CCM is not requesting DRL operation.

FAILURE CONDITIONS

DTC 37 will set if terminal "A8" is grounded, and after CCM wake-up, the CCM does not see a chance of state at terminal "A3" when requesting DRL operation.

This fault cannot be detected on an American vehicle as there is no DRL relay and because of this the diagnostic feedback (in the CCM) will always be low.

Minimum detection time: 2 seconds.

On Non-Canadian vehicles terminal "A8" is not grounded.

ACTION TAKEN

DTC 37 will set.

TEST DESCRIPTION

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

1. This test checks for an open, short to ground in CKT 1640.

2. This test checks for an internal open in the relay.

3. This test checks for an internal short in the relay which would cause a short to ground.

4. This test checks for a short to ground in CKT 592.

5. This test determines whether an open indicated in Test 5 lies in the wiring or connection to CKT 592 or in the CCM itself.

DIAGNOSTIC AIDS

If the DTC is a history code, the problem may be intermittent. Try performing the test shown while "wiggling" wiring and connectors; this can often cause the fault to appear. Check for poor connections at both the CCM and the DRL relay connector; these could cause an open or an intermittent fault. Refer to "Intermittents/History Codes/Poor Connections". Intermittents/History DTCs

If CKT 592 is shorted to ground, the DRL function will be "ON" at all times. If CKT 592 is open, the DRL function will be "OFF," and the CCM will command the headlights "ON."

A Tech 1 can be used to activate the DRL relay.

Check for a DTC 147. This could mean an intermittent short to B+ at the CCM Canadian select input.