For 1990-2009 cars

### Circuit Description

The low air indicator illuminates when ground is applied to the low air indicator control circuit.

Step | Action | 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 Brake Warning System Description and Operation
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 | Is the low air indicator and the brake warning alarm inoperative? | Go to Low Air Indicator Inoperative | Go to Step 4
4 |

1. Disconnect the multifunction alarm module.
2. Connect a test lamp from the battery positive voltage circuit to the ground circuit.
3. Turn the ignition ON.

Does the test lamp light?

Go to Step 6

Go to Step 5

5 | Connect a test lamp from the battery positive voltage circuit to a good ground . Does the test lamp light? | Go to Step 8 | Go to Step 9
6 | Test the low air indicator control circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 10 | Go to Step 7
7 | Replace the multifunction control module. Refer to Multifunction Alarm Module Replacement in Instrument Panel, Gages, and Console Did you complete the replacement? | Go to Step 10 | --
8 | Repair the open in the ground circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 10 | --
9 | Repair the open in the battery positive voltage circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 10 | --
10 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2