Vehicle Speed Signal, Checking: Notes

GENERAL DESCRIPTION 

The Vehicle Speed Signal Or VSS Measures Transmission / Transaxle Output Or Wheel Speed From The ABS System. The Signal Is Broadcasted Over The CAN Bus. The Engine Control Module -J623- Uses This Information To Modify Engine Functions Such As Ignition Timing, A/F Ratio, Transmission Shift Points, And To Initiate Diagnostic Routines.

Special Tools And Workshop Equipment Required 

• Multimeter.
• Wiring Diagram.
• Scan Tool.

TEST REQUIREMENTS 

• Fuses OK.
• Battery voltage OK.
• Switch OFF all electrical and electronic accessories.
• Vehicles with Auto. Transmission, ensure Selector Lever position is in "P".
• Vehicles with Man. Transmission, ensure Shifter Lever position is in "N" with Parking Brake applied.
• Observe all safety precautions: SAFETY PRECAUTIONS .
• View clean working conditions: CLEAN WORKING CONDITIONS .
• For Hybrid vehicles refer to: HIGH VOLTAGE SYSTEM GENERAL WARNINGS .