Circuit Description
The Low Air Indicator illuminates when ground is applied to the Low Air Indicator Control Circuit.
Test Description
The number below refer to the step number on the diagnostic table.
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This step should be performed on both low air pressure switches.
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This step should be performed on both ground circuits.
Step | Action | Yes | No |
|---|---|---|---|
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Important: This system utilizes two Low Air Pressure switch circuits in parallel. In order to cause this symptom both circuits must be inoperative. 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 | |
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 |
Does the low air indicator illuminate? | Go to Step 9 | Go to Step 4 | |
Connect the fused jumper wire from the low air indicator control circuit to a good ground . Does the low air indicator illuminate? | Go to Step 7 | Go to Step 5 | |
5 | 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 6 |
6 | Replace the Instrument Panel Cluster. Did you complete the replacement? | Go to Step 10 | -- |
7 | Repair the open in the ground circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 10 | -- |
8 | 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 | -- |
9 | Replace the Low Air Pressure switch. Refer to Low Air Pressure Switch Replacement . Did you complete the replacement? | 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 |
