GM Service Manual Online
For 1990-2009 cars only

Brake Warning Alarm Always On for Chevrolet Chevrolet C-Series Medium Duty Truck B7 2001

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?

--

Go to Step 2

Go to Symptoms - Hydraulic Brakes

2

Verify a fault is present.

Does the system operate normally?

--

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?

--

Go to Step 7

--

7

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2