Circuit Description
The electronic brake control module (EBCM) illuminates the service brake soon indicator by applying ground to the lamp.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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This step tests if the EBCM is applying ground to the brake indicator signal circuit.
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This step tests for a short to ground in the brake indicator signal circuit by substituting the telltale circuit board with a test lamp.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Brake Warning System Schematics Important: After DTC C0272 is cleared and the ignition is ON, the service brake soon indicator may remain ON until the vehicle is operated at a speed greater than 10 km/h (6 mph). | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
2 | Turn ON the ignition while observing the service brake soon indicator. Does the service brake soon indicator illuminate for 3 seconds and then turn OFF? | Go to Testing for Electrical Intermittents in Wiring Systems | Go to Step 3 |
Does the service brake soon indicator illuminate? | Go to Step 4 | Go to Step 7 | |
Does the test lamp illuminate? | Go to Step 5 | Go to Step 6 | |
5 | Repair the short to ground in the brake indicator signal circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 8 | -- |
6 | Replace the telltale circuit board. Refer to Telltale Circuit Board Replacement in Instrument Panel, Gages and Console. Did you complete the replacement? | Go to Step 8 | -- |
7 | Replace the EBCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | Go to Step 8 | -- |
8 | Turn ON the ignition while observing the service brake soon indicator. Does the service brake soon indicator illuminate for 3 seconds and then turn OFF? | System OK | Go to Step 3 |
