Symptom Tree t164
| Cause | Correction |
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Active air shutoff valve fault code(s) |
Troubleshoot any active air shutoff valve fault codes first. |
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Air shutoff lamp stays illuminated |
Troubleshoot the air shutoff lamp circuit. Verify the proximity switch operation. The switch is normally open. The circuit is closed when the valve is in the closed position. |
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Fault Code 1117 active |
Troubleshoot active Fault Code 1117. |
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Battery charge low |
Check the batteries. Charge or replace if necessary. |
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Verify the truck switches and wiring |
Check the resistance and wiring in the truck dash for the air shutoff valve switches. |
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Verify the proximity switch resistance |
Disconnect the proximity switch from the OEM harness and check the resistance of the switch. The switch resistance should be between 15 and 25 ohms. Replace the switch if not within specification. |
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Verify the diagnostic voltage from the ECM connector |
Disconnect the OEM harness from the ECM and verify the diagnostic voltage. Replace the ECM if 5-VDC is present. Refer to Procedure 019-031 in Section 19. If 5-VDC is not present, troubleshoot the OEM harness. Refer to Procedure 019-043 in Section 19. |
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Verify the air shutoff valve operation. Note: The air shutoff valve may become sluggish over time. |
The air shutoff valve must close. Replace, as necessary. |
