Diagnostic Aids

1991 Mercury Tracer Base, 4D Sedan, AutomaticSECTION Diagnostic Aids
WARNING: This page does not describe the selected car, but rather 15 other vehicles, including the 1992 Mercury Tracer, 1992 Mercury Topaz, 1992 Mercury Sable, 1992 Mercury Grand Marquis, and 1992 Mercury Cougar. However, it is still accessible from the selected car via links, so may be relevant.

Perform this test when directed by QUICK TESTΒ  . This CIRCUIT TEST is intended to diagnose:

  • Vehicle Speed Sensor (VSS).
  • VSS wiring harness circuits.
  • ECA.
Fig 1: Vehicle Speed Sensor Circuit
G90G12407
TEST PIN NO. 3 (VSS +) WIRE COLOR IDENTIFICATION

Application Wire Color
Escort 1.9L & Tracer 1.9L White/Black
Continental, Crown Victoria, Explorer Grand Marquis, Mustang & Town Car Gray/Black
Probe 3.0L Black/Red
All Others Dark Green/White
TEST PIN NO. 6 (VSS -) WIRE COLOR IDENTIFICATION

Application Wire Color
Cougar & Thunderbird Gray/Red
Escort 1.9L & Tracer 1.9L Blue
Probe 3.0L Black/Blue
Tempo, Topaz, Sable & Taurus Orange/Yellow
Town Car Black/Light Blue
All Others Pink/Orange
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.