DTC C1287 identifies one of the following conditions:
• | An open or short to voltage between the EBTCM and the red BRAKE warning indicator. |
• | An open driver that does not allow the EBTCM to illuminate the red BRAKE warning indicator. |
DTC C1287 will only occur if an ABS malfunction is detected that may degrade base brake operation.
A short to ground in the circuit cannot be detected because the EBTCM is not the only device controling the red BRAKE warning indicator. The following components may also turn on the red BRAKE warning indicator:
• | The parking brake indicator switch |
• | The brake fluid level indicator sensor |
DTC C1287 can set during the three second bulb check and after completing initialization.
A malfunction exists if the red BRAKE warning indicator circuit voltage is out of specification. If the circuit voltage is out of specification, an open circuit or a short to voltage exists.
• | A malfunction DTC stores. |
• | The ABS/ETS does not disable. |
• | The amber ABS/ETS warning indicator will flash to indicate a serious problem if the following conditions occur: |
1. | The EBTCM commands the red BRAKE warning indicator on due to an ABS malfunction that may degrade base brake operation. |
2. | The red BRAKE warning indicator cannot turn on. |
• | The condition responsible for setting the DTC no longer exists and the Scan Tool Clear DTCs function is used. |
• | 100 drive cycles pass with no DTCs detected. |
If the malfunction is not current, use wiggle test on the wiring harness to pinpoint an intermittent malfunction in the motor circuitry or connections. Thoroughly inspect any circuitry that may be causing the intermittent complaint for the following conditions:
• | Backed out terminals |
• | Improper mating |
• | Improperly formed or damaged terminals |
• | Poor terminal-to-wiring connections |
• | Physical damage to the wiring harness |
• | Rubbed-through wire insulation |
• | A broken wire inside the insulation |
Use the enhanced diagnostic function of the Scan Tool in order to measure the frequency of the malfunction. If the Scan Tool is not available, lift the parking brake handle in order to verify proper indicator operation and continuity of CKT 33 and CKT 39.
Step | Action | Value(s) | Yes | No | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Was the Diagnostic System Check performed? | -- | ||||||||||||||
2 |
Is the voltage within the specified range? | 0.0-1.0 V | ||||||||||||||
3 |
Do not start the engine. Is the red BRAKE warning indicator on? | -- | ||||||||||||||
4 | Inspect the master cylinder brake fluid level. Is the brake master cylinder fluid full? | -- | ||||||||||||||
5 |
Do not start the engine. Is the voltage within the specified range? | 0.0-2.0 V | ||||||||||||||
6 |
Is there poor terminal contact, terminal corrosion, or terminal damage? | -- | ||||||||||||||
7 |
Does DTC C1287 set as a current DTC? | -- | ||||||||||||||
8 |
Does DTC C1287 set as a current DTC? | -- | ||||||||||||||
9 |
Is the red BRAKE warning indicator lamp open? | -- | ||||||||||||||
10 | Use the J 39200 in order to measure the resistance between the instrument panel cluster connector C1 terminal B3 and the 24-way EBTCM connector C1 terminal B5. Is the resistance within the specified range? | 0.0-2.0 ohms | ||||||||||||||
11 |
Do not start the engine. Is the red BRAKE warning indicator on? | -- | ||||||||||||||
12 | Install the scan tool in order to inspect for DTCs. Is DTC C1286 set as either a current and/or history DTC? | -- | Go to DTC C1286 EBCM/EBTCM Turned On Brake Warning Indicator | |||||||||||||
13 |
Is the resistance within the specified range? | OL (Infinite) | ||||||||||||||
14 |
Is the red BRAKE warning indicator on? | -- | ||||||||||||||
15 |
Is the voltage within the specified range? | 0.0-1.0 V | ||||||||||||||
16 |
Damage may result in a short to voltage with the 24-way EBTCM connector C1 connected. Is there any damage to CKT 209 or the 24-way EBTCM connector C1 which may cause a short to voltage? | -- | ||||||||||||||
17 |
Does DTC C1287 set as a current DTC? | -- | ||||||||||||||
18 | Fill the brake master cylinder with approved brake fluid such as SUPREME 11 (GM Brand) or equivalent DOT 3 brake fluid. Is the brake master cylinder full? | -- | -- | |||||||||||||
19 | Repair the open or the high resistance in the park brake wiring. Is the repair complete? | -- | -- | |||||||||||||
20 | Replace all the terminals or the connectors that exhibit any of the following conditions:
Is the repair complete? | -- | -- | |||||||||||||
21 | Repair the open or the high resistance in the master cylinder brake fluid level indicator sensor. Is the repair complete? | -- | -- | |||||||||||||
22 | Replace the park brake indicator switch. Refer to Parking Brake Indicator Switch Replacement . Is the repair complete? | -- | -- | |||||||||||||
23 | Repair the short to voltage in CKT 39 or CKT 209. Is the repair complete? | -- | -- | |||||||||||||
24 | Repair the damage to CKT 209 or the 24-way EBTCM connector C1. The damage may cause a short to voltage. Is the repair complete? | -- | -- | |||||||||||||
25 | Repair the open or the high resistance in CKT 209 between the following components:
Is the repair complete? | -- | -- | |||||||||||||
26 | Replace the EBTCM. Refer to Electronic Brake and Traction Control Module Replacement . Is the repair complete? | -- | -- | |||||||||||||
27 | Is the malfunction intermittent or is not present at this time? | -- | Go to Diagnostic Aids | -- | ||||||||||||
28 | Replace the red BRAKE warning indicator light bulb. Is the repair complete? | -- | -- |