Overview, Diagnostic trouble code (dtc) detection, Symptom – Bendix Commercial Vehicle Systems VORAD VS-400 INSTALLATION NOTES User Manual
Page 31: Possible causes, Repair procedure

General Information
29
Diagnostic Trouble Code (DTC)
Isolation Procedures
Component Code: 41, 42
(SPN 1703, 1704, FMI 4, 5)
Driver Interface Unit External Speaker Diagnostic Trouble Code (DTC)
Overview
Most vehicles use the DIU as a source of audio alerts, however, the chassis manufacturer has the option to install an external chassis
speaker system . For systems with external speaker systems, this code indicates that the VS-400 Driver Interface Unit (DIU) has detected
that the external speaker circuit has an open circuit or short to ground .
Diagnostic Trouble Code (DTC) Detection
If the DIU is enabled for external speakers and the speaker circuit becomes open or shorted to ground this code is set active .
•
Code 41, FMI 4 - RH Speaker circuit is shorted to ground
•
Code 41, FMI 5 - RH Speaker circuit is open
•
Code 42, FMI 4 - LH Speaker circuit is shorted to ground
•
Code 42, FMI 5 - LH Speaker circuit is open
Symptom
When this code is active, the Bendix
™
VORAD
®
VS-400 system will not operate and the orange DTC fail light on the DIU will be illuminated .
If SmartCruise
®
adaptive cruise control is enabled and the engine is enabled for adaptive cruise, the vehicle’s cruise control may not
operate .
Possible Causes
•
Loose, corroded, or open external speaker connections
•
Pinched wire or shorted external speaker
•
External speaker configuration enabled without external speaker connected
Repair Procedure
Active Diagnostic Trouble Code
Steps to Perform
Code 41, FMI 4
1 .
Check for a short to ground by measuring the resistance between Pin-1 and
Pin-5 of the DIU harness connector .
a .
If value is less than 2 ohms, test failed . Check external speaker and
harness for short to ground . Repair as needed .
b .
If value is 2 to 5 ohms, continue to next step .
2 .
Replace DIU and verify Diagnostic Trouble Code (DTC) condition has cleared .
3 .
Test Complete .