Central Control Module (CCM)

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

The Daytime Running Lamps (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".

DTC WILL SET WHEN

CCM is awake and is configured as a Canadian vehicle, the DRL enable function of the CCM is not requesting DRL operation, and voltage stays "low" at terminal "A3" for 2 or more seconds.

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.

ACTION TAKEN

DTC 37 will set. If CKT 592 is open, the DRL function will be "OFF," and the CCM will command the headlamps "ON."

DTC WILL CLEAR WHEN

DTC 37 will clear if the fault goes away for 2 or more seconds.

DTC CHART 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 1840.

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

3. This test checks for and 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 DTC, 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 DTCs". Intermittents/History DTCs

A Tech 1 can be used to activate the DRL relay. Check for a DTC 147. This could mean an intermittent short to B+, ground, or open at the CCM Canadian select input.