GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1998 🢒 Chevy P12 Chassis 🢒 Brakes 🢒 Hydraulic Brakes 🢒 Brake Warning Indicator Inoperative

Troubleshooting Hints

Prior to beginning the formal diagnostic procedures, check for the following conditions:

    • Check to see if the BRAKE lamp comes on when the pull button is engaged if the start up bulb check passes.
    • If the auto apply park brake actuator travels further than desired and the BRAKE lamp turns on, the parking brake cable may need adjustment.

Step

Action

Value(s)

Yes

No

1

Observe the BRAKE lamp when the engine is started.

Does the BRAKE lamp turn on when the ignition switch is in the START position?

 

Go to Step  13

Go to Step  2

2

Inspect fuse 4 (GAUGES) in the IP fuse block.

Is fuse 4 blown?

--

Go to Step  3

Go to Step  4

3
  1. Check the wiring harness for a short to ground in CKT 1471 (YEL/BLK) and CKT 1134 (LT BLU).
  2. Repair the wire harness if a short circuit was located.
  3. Replace fuse 4.

Is the repair complete?

--

System OK

--

4
  1. Place the ignition switch in the RUN position.
  2. Connect a test lamp from the metallic part of fuse 4 to ground.

Does the test lamp illuminate?

--

Go to Step  6

Go to Step  5

5

Repair the power supply circuit for fuse 4.

Is the repair complete?

--

System OK

--

6
  1. Disconnect the instrument cluster connector.
  2. Place the ignition switch in the RUN position.
  3. Connect a test lamp from terminal 22 (PNK) of the instrument cluster connector to ground.

Does the test lamp illuminate?

--

Go to Step  8

Go to Step  7

7

Locate and repair the open in the CKT 39 (PNK) wire between fuse 4 in the IP fuse block and the instrument cluster.

Is the repair complete?

--

System OK

--

8
  1. Place the ignition switch in the RUN position.
  2. Connect a test lamp to ground.
  3. Use the test lamp to backprobe terminal F (YEL/BLK) of the daytime running lamp (DRL) module.

Does the test lamp illuminate?

--

Go to Step  14

Go to Step  9

9

Connect a DMM J 39200 between terminal F (YEL/BLK) of the DRL module and terminal 28 (YEL/BLK) of the instrument cluster connector.

Does the DMM indicate the specified resistance?

<1 ohms

Go to Step  11

Go to Step  10

10

Locate and repair the open in the CKT 1471 (YEL/BLK) wire between the instrument cluster and the DRL module.

Is the repair complete?

--

--

System OK

11

Visually and physically check the BRAKE lamp.

Is the BRAKE lamp okay?

--

Go to Step  13

Go to Step  12

12

Replace the BRAKE lamp.

Is the repair complete?

--

System OK

--

13

Replace the instrument cluster.

Is the repair complete?

--

System OK

--

14
  1. Place the ignition switch in the RUN position.
  2. Connect a test lamp to ground.
  3. Use the test lamp to backprobe terminal A (LT BLU) of the daytime running lamp (DRL) module.

Does the test lamp illuminate?

--

Go to Step  16

Go to Step  15

15

Replace the DRL module.

Is the repair complete?

 

System OK

--

16
  1. Remove the pull button relay from the IP convenience center.
  2. Place the ignition switch in the RUN position.
  3. Connect a test lamp between terminal H1 (LT BLU) of the pull button relay socket and ground.

Does the test lamp illuminate?

--

Go to Step  17

Go to Step  18

17

Locate and repair the open in the CKT 1134 (LT BLU) wire between the DRL module and the pull button relay socket.

Is the repair complete?

--

System OK

--

18
  1. Remove the pull button relay from the IP convenience center.
  2. Connect a jumper wire from terminal H1 (LT BLU) of the pull button relay socket to terminal G2 (BLK) of the pull button relay socket.
  3. Place the ignition switch in the RUN position.

Does the BRAKE illuminate?

--

Go to Step  20

Go to Step  19

19

Locate and repair the open in the CKT 150 (BLK) wire between ground and terminal G2 of the pull button relay socket.

Is the repair complete?

--

System OK

--

20

Replace the pull button relay.

Is the repair complete?

--

System OK

--