GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The Low Air Indicator illuminates when ground is applied to the Low Air Indicator Control Circuit.

Step

Action

Values

Yes

No

Schematic Reference: Brake Warning System Schematics

1

Did you review the Brake Warning System Description and Operation and perform the necessary inspections?

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Go to Step 2

Go to Symptoms - Hydraulic Brakes

2

Verify a fault is present.

Does the system operate normally?

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

Go to Step 3

3

Does the Low Air Indicator and the Brake Warning Alarm come on?

--

Go to Low Air Indicator Always On

Go to Step 4

4

  1. Start the vehicle.
  2. Inspect the air pressure gage.

Does the air pressure gage indicate the air pressure is above the specified value?

480 kPa (70 psi)

Go to Step 5

Go to Air Brake System Leak Test

5

Inspect the Low Air Indicator Control Circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 7

Go to Step 6

6

Replace the Multifunction Alarm Module. Refer to Multifunction Alarm Module Replacement in Instrument Panel, Gages, and Console.

Did you complete the replacement?

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Go to Step 7

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7

Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 2