GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

Schematic Reference: Brake Warning System Schematics

1

Did you review the Hydraulic Brakes operation and perform the necessary inspections?

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Go to Step 2

Go to Symptoms - Hydraulic Brakes

2

Inspect the brake fluid level.

Is the brake fluid level OK?

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Go to Step 3

Go to Brake Fluid Leak

3

  1. Turn OFF the ignition.
  2. Install a scan tool.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the Low Brake Fluid Level parameter in the IPC Inputs data list.

Does the scan tool indicate that the Low Brake Fluid Level parameter is Off?

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Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 4

4

  1. Turn OFF the ignition.
  2. Disconnect the brake fluid level switch.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the Low Brake Fluid Level parameter in the IPC Inputs data list.

Does the scan tool indicate that the Low Brake Fluid Level parameter is Off?

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Go to Step 6

Go to Step 5

5

Test the signal circuit of the brake fluid level switch for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 10

Go to Step 7

6

Inspect for poor connections at the harness connector of the brake fluid level switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 10

Go to Step 8

7

Inspect for poor connections at the harness connector of the instrument cluster (IPC). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

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Go to Step 10

Go to Step 9

8

Replace the brake fluid level switch. Refer to Brake Fluid Level Indicator Switch Replacement .

Did you complete the repair?

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Go to Step 10

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9

Replace the instrument cluster (IPC). Refer to Instrument Cluster Replacement in Instrument Panel, Gauges and Console.

Did you complete the repair?

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Go to Step 10

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10

Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 2