Nissan VSS-From-Instrument Cluster Investigation

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ROSTRA PRECISION CONTROLS

Nissan VSS-from-instrument cluster investigation

Executive Summary:

On the Nissan Frontier/Titan applications, VSS is obtainable from a single wire in the instrument cluster and the Controller Area Network (CAN). The instrument cluster VSS wire is not always pre-installed because, in this case, it is not part of a safety critical system; it only used for accessories.

Inside the instrument cluster, the VSS generating circuit is configured to be a “open collector/drain”. This means the circuit switches between the GND and Open Circuit (Hi-Z) states. This circuit configuration is not able to be reliably detected in all cases by the current 57A-02360 without modification; an additional resistor (pull-up resistor) is needed to complete the circuit. When the VSS wire is pre-installed and is connected to other Nissan accessories, the Nissan accessories provide this pull-up resistor and 57A-02360 installation is reliable.

Engineering recommendation: revisit all accessible installations and replace modules with module with 100KOhm pull-up resistor built in. Modify all in-house stock to include pull-up resistor, and replace all distributer stock with modified units.

57A-02360 fault report

Nissan VSS-from-instrument cluster investigation

INTRODUCTION AND ISSUE HISTORY

Several 250-1856 kits have been returned to Rostra with various failure modes being listed as the reason for the return. The reported malfunctions ranged from: “Cruise doesn’t work right” to Mr. Garret’s issue of unintended and erratic acceleration. On Thursday, February 25, 2010 an investigation was launched when the unintended acceleration malfunction was reported to Rostra Engineering.

First, S.McDougald (Technician - Ros...

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...REWORK INSTRUCTIONS

All solder work must be done with ESD protection at properly grounded work stations.

Step 1

Remove back cover of 57A-02360 using a T-8 Torx driver. (Photo 1) Lift the cover and set aside. Locate pins 2,3 of the 12-pin Molex connector (Photo 2)

Step 2

Without removing the PCB from the upper portion of the case, dispense a small quantity of liquid flux between pins 2 and 3 of the 12-pin Molex connector. (Photo 3)

Step 3

Solder a 100KOhm 0805 5% resistor between pins 2 and 3 of the 12-pin Molex connector. (Photo 4) Take care not to create a short circuit to the Via marked in Photo 4.

Step 4

Replace the back cover of the cruise control. Use a permanent marker to mark a dot after the serial number, See below:

Step 5

Execute testing procedure.

• If test is OK: Proceed with kit assembly

• If test FAILED: Send module to Quality Assurance

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