Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Brake Warning System Schematics | ||||
1 | Did you review the Brake Warning System Description and Operation and the Brake Assist System Description and Operation and perform the necessary inspections? | -- | Go to Step 2 | |
2 | Start the engine. Is the reduced brake power message displayed within 5 seconds? | -- | Go to Step 3 | |
3 | Is the service brake booster message displayed within 5 seconds? | -- | Go to Step 6 | Go to Step 4 |
4 | Operate the vehicle at a speed greater than 48 km/h. Is the service brake booster message displayed? | -- | Go to Step 5 | Go to Diagnostic Aids |
5 | Test the charging system for proper operation. Refer to Charging System Test in Engine Electrical. Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 21 |
6 |
Does the test lamp illuminate? | -- | Go to Step 7 | Go to Step 12 |
7 | Test each SBA ground circuit for an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 8 |
8 | Connect a test lamp between the engine ON signal circuit and a good ground. Does the test lamp illuminate? | -- | Go to Step 10 | Go to Step 9 |
9 | Repair the open in the engine ON signal circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 22 | -- |
10 | Use a DMM to measure the voltage between the vehicle speed signal circuit and a good ground. Does the voltage measure greater than the specified value? | 10 V | Go to Step 13 | Go to Step 11 |
11 | Repair the open in the vehicle speed signal circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 22 | -- |
12 | Repair the open in the ignition 1 circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 22 | -- |
13 | Use a DMM to measure the voltage between the supplemental brake assist circuit and a good ground. Does the voltage measure greater than the specified value? | 11 V | Go to Step 16 | Go to Step 14 |
14 |
Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 15 |
15 | Inspect for poor connections at the IPC harness connector. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 19 |
16 | Connect a test lamp between the SBA signal circuit and a good ground. Does the test lamp illuminate? | -- | Go to Step 17 | Go to Step 20 |
17 |
Does the test lamp illuminate? | -- | Go to Step 18 | Go to Step 19 |
18 | Repair the short to voltage in the SBA signal circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 22 | -- |
19 | Replace the IPC. Refer to Instrument Cluster Replacement in Instrument Panel, Gages, and Console. Did you complete the replacement? | -- | Go to Step 22 | -- |
20 | Inspect for poor connections at the SBA harness connector. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 21 |
21 | Replace the SBA pump motor assembly. Refer to Power Brake Booster Auxiliary Pump Replacement . Did you complete the replacement? | -- | Go to Step 22 | -- |
22 |
Is the service brake booster message displayed? | -- | Go to Step 2 | System OK |
