Turn the ignition to RUN.

Does the ABS lamp illuminate for a few seconds and then go off?

--

Go to Step 2

Go to Step 15

Listen for an alarm.

Does the park brake alarm sound while the BRAKE lamp is on?

--

Go to Step 16

Go to Step 3

Check the instrument panel.

Is the low coolant lamp on as well as the BRAKE lamp?

--

Go to Step 17

Go to Step 4

1. Turn the ignition to LOCK.
2. Open the end of the DRL module housing.
3. Carefully remove the DRL module from its connector and place it where it will be safe from electrostatic damage.
4. Turn the ignition to RUN and check the BRAKE lamp.

Is the BRAKE lamp illuminated?

--

Go to Step 5

Go to Step 6

Find and repair the short to ground in circuit 1471 (YEL/BLK) between terminal F of the DRL module and terminal 28 on the instrument cluster.

Is the repair complete?

--

System OK

--

With the ignition in RUN, backprobe the DRL module connector terminal E with a test lamp to B+.

Does the lamp illuminate?

--

Go to Step 10

Go to Step 7

With the ignition in RUN, backprobe the DRL module connector terminal A with a test lamp to B+.

Does the lamp illuminate?

--

Go to Step 9

Go to Step 8

Replace the DRL Module.

Is the repair complete?

--

System OK

--

1. Locate the fault in the park brake pull button switch circuit:

•	A short to ground in circuit 1134 (LT BLU) between the DRL module terminal A and the pull button relay terminal 30 (H1 in the IP Wiring Harness Junction Block).

•	An open in circuit 150 (BLK) between the pull button relay terminal 86 (H3) and splice S201.

•	An open in circuit 909 (YEL) between splice S212 and the pull button terminal 85 (G1).

•	A faulty pull button relay.

2. Repair the fault found.

Is the repair complete?

--

System OK

--

1. Turn the ignition LOCK.
2. Replace the DRL module into its connector and close the housing.
3. Open the diode network housing and carefully remove the circuit board from its connector.
4. Turn the ignition to RUN

Is the BRAKE lamp illuminated?

--

Go to Step 11

Go to Step 12

Find and repair the short to ground in circuit 33 (TAN/WHT) between the DRL module terminal E and the diode network terminals G and H.

Is the repair complete?

--

System OK

--

1. Turn the ignition to LOCK.
2. Replace the diode network into its connector.
3. Disconnect the connector from the brake differential switch.
4. Turn the ignition to RUN.

Is the BRAKE lamp illuminated?

--

Go to Step 13

Go to Step 14

Find and repair the short to ground in circuit 680 (PPL) between the brake pressure differential switch and the diode network, terminal B, and the EBCM, connector C1, terminal H.

Is the repair complete?

--

System OK

--

1. Perform a brake system diagnostic to find the leak or other source of the pressure differential.
2. Repair and bleed the hydraulic system.
3. Reset the pressure differential switch.

Is the repair complete?

--

System OK

--

Check for ABS DTCs and repair as indicated.

Is the repair complete?

--

System OK

--

1. Check for one of the following problems in the park brake alarm circuit:

•	A short to ground in circuit 920 (ORN) in one of the following areas:

•	between the diode network terminal A and splice S205

•	between S205 and the park brake alarm terminal A

•	between S205 and the park brake alarm relay terminal 30 (C6 in the Engine Wiring Harness Junction Block)

•	An open in circuit 906 (PPL/WHT) between the park brake alarm relay terminal 86 (C4) and the park brake actuator position switch terminal A

•	An open in circuit 150 (BLK) between the park brake actuator position switch terminal B and ground G400

•	A faulty park brake actuator position switch

•	A faulty park brake alarm relay

•	An open in circuit 639 between splice S111 and the park brake alarm relay terminal 85 (D6)

2. Repair the problem as required.

Is the repair complete?

--

System OK

--

1. Check for one of the following faults in the ignition switch circuit:

•	A short to ground in circuit 1134 (LT BLU) between the DRL module and splice S216

•	A short to ground in circuit 1134 (LT BLU) between S216 and the diode network terminal C

•	A short to ground in circuit 1134 (LT BLU) between S216 and the ignition switch

•	A faulty ignition switch

2. Repair as needed.

Is the repair complete?

--

System OK

--