Diagnostic Aids

Typical causes of the ABS warning lamp inoperative with no DTCs set:

Faulty bulb/loose socket
I/P fuse open
Faulty cluster/lamp driver module
Faulty EBCM
Grounded circuit between the EBCM and the cluster

Brake Warning Indicator Inoperative

Step	Action	Value(s)	Yes	No
1	Did you review the brake warning system circuit description and perform the necessary inspections?	-	Go to Step 2	Go to Symptoms - Hydraulic Brakes
2	Disconnect the EBCM harness from the EBCM. Turn ON the Ignition switch. Did the brake warning lamp turn ON?	-	Go to Step 3	Go to Step 4
3	Replace the EBCM. Is the fuse and the terminal contact OK?	-	System OK	-
4	Check the cluster fuse. Did you complete the replacement?	-	Go to Step 6	Go to Step 5
5	Replace the open fuse and/or repair the loose terminals. Find the short, which caused the fuse to open, if applicable. Did you find and correct the condition?	-	System OK	-
6	Remove the brake warning lamp bulb from the cluster and inspect for an open bulb filament or poor socket contact? Was the socket and bulb OK?	-	Go to Step 8	Go to Step 7
7	Replace the Bulb/Socket as needed. Did you complete the replacement?	-	System OK	-
8	Turn OFF the Ignition switch. The EBCM harness is still disconnected. Remove the cluster assembly from the instrument panel. Disconnect the white cluster harness connector from the cluster assembly. Turn the ignition switch ON. Connect a voltmeter to terminal 11 of the white cluster harness and then to body ground. Was the voltage within the specified value?	11-14 V	Go to Step 10	Go to Step 9
9	Find and repair the source of the low voltage on the cluster voltage supply terminal.	-	System OK	-
10	Turn OFF the ignition switch. Disconnect the white cluster harness connector from the cluster assembly. Connect an ohmmeter between the white cluster harness terminal 6 and the lamp driver module (LDM) harness terminal A. Was the resistance measured less than the specified value?	2 Ω	Go to Step 12	Go to Step 11
11	Repair the open or high resistance between the cluster and the LDM. Did you find and correct the condition?	-	System OK	-
12	Turn OFF the ignition switch. The LDM harness and EBCM harness still are disconnected. Connect an ohmmeter to the EBCM harness terminal 18 and then to body ground. Was the resistance within the specified value?	OL (open circuit)	Go to Step 14	Go to Step 13
13	Find and repair the short to ground between the LDM harness and the EBCM harness. Did you find and correct the condition?	-	System OK	-
14	Replace the LDM. Did you complete the replacement?	-	System OK	Go to Step 15
15	Replace the cluster assembly. Did you complete the replacement?	-	System OK	-