GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Remove the DRL ON Relay.

Do the DRL/headlamps disengage when the engine is not running?

--

Go to Step 3

Go to Step 2

2

  1. Repair the short to ground in CKT 741 (BLK/DK GRN) between the DRL ON relay and the DRL OFF relay.
  2. Install the DRL ON relay.

Is the repair complete?

--

System OK

--

3

  1. Repair the short to ground in CKT 729, 730 (RED/BLK) between the DRL ON relay and the DRL indicator lamp diode or the DRL series dropping resistor.
  2. Install the DRL ON relay.

Does the DRL/headlamps disengage when the engine is not running?

--

System OK

Go to Step 4

4

Remove the lighting relay.

Do the DRL/headlamps disengage when the engine is not running?

--

Go to Step 6

Go to Step 5

5

  1. Repair the short to ground in CKT 715 (RED/YEL) between the lighting relay and the DRL series dropping resistor.
  2. Install the lighting relay.

Is the repair complete?

--

System OK

--

6

  1. Repair the short to ground in CKT 691, 697 (RED/BLK) between the lighting relay and the headlamps.
  2. Install the lighting relay.

Does the DRL/headlamps disengage when the engine is not running?

--

System OK

--