Diagnostic Aids

Typical causes of no communication with the EBCM:

Poor terminal contact at the EBCM
Loss of EBCM ground to terminal 8 and 24
Loss of battery voltage at EBCM terminals 9 and/or 25
Loss of ignition voltage at EBCM 4
Open/grounded data line
Data line with high resistance

No Communication with EBCM

Step	Action	Value(s)	Yes	No
1	Did you perform a Diagnostic System Check?	-	Go to Step 2	Go to Diagnostic System Check - ABS
2	Turn the ignition switch OFF. Disconnect the electronic brake control module (EBCM) harness. Connect a voltmeter to the EBCM harness terminal 9 and then to body ground. Was the voltage measured within the specified value?	B+	Go to Step 4	Go to Step 3
3	Repair the source of the low voltage to terminal 9. Inspect for an open fuse, poor terminal contact, or a grounded wire. Did you find and correct the condition?	-	System OK	-
4	Connect a voltmeter to the EBCM harness terminal 25 and then to the body ground. Was the voltage measured within the specified value?	B+	Go to Step 6	Go to Step 5
5	Repair the source of the low voltage to terminal 25. Inspect for an open fuse, poor terminal contact, or a grounded wire. Did you find and correct the condition?	-	System OK	-
6	Turn ON the ignition, with the engine OFF. Connect a voltmeter to the EBCM harness terminal 4 and then to body ground. Was the voltage measured within the specified value?	B+	Go to Step 8	Go to Step 7
7	Repair the source of the low voltage to terminal 4. Inspect for an open fuse, poor terminal contact, or a grounded wire. Did you find and correct the condition?	-	System OK	-
8	Turn the ignition switch OFF. Connect an ohmmeter to the EBCM harness terminal 8 and 24 and then to body ground. Was the resistance measured less than the specified value?	2 Ω	Go to Step 10	Go to Step 9
9	Repair the source of the high resistance between terminal 8 and 24 and body ground. Find and check the ground location where the circuit is secured to body ground. Did you find and correct the condition?	-	System OK	-
10	Turn OFF the ignition switch. The EBCM harness is still disconnected from the EBCM. Connect an ohmmeter to the EBCM harness terminal 7 and the DLC terminal 7. Was the resistance measured less than the specified value?	2 Ω	Go to Step 12	Go to Step 11
11	Repair the high resistance between EBCM terminal 21 and DLC terminal 7. Is the repair complete?	-	System OK	-
12	Turn the ignition switch OFF. The EBCM harness is still disconnected. Connect an ohmmeter to the EBCM harness terminal 7 and then to body ground. Was the resistance measured equal to the specified value?	OL (open circuit)	Go to Step 14	Go to Step 13
13	Find and repair the short to ground on the data line. Did you find and correct the condition?	-	System OK	-
14	Replace the EBCM. Refer to Brake Modulator Assembly Replacement . Did you complete the replacement?	-	System OK	-