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 circuit test when directed by other CIRCUIT TESTS. This test is only intended to diagnose:

  • ECA.
  • Throttle plate linkage.

1) Check For Codes 23, 53, 63, 121, 122 & 123  Disconnect cruise control servo wiring harness connector. Perform KOEO SELF-TEST  . If Code 23, 53, 63, 121, 122 or 123 is present, go to appropriate CIRCUIT TEST. See SERVICE CODE REFERENCE CHARTS  , and service codes as necessary. If Code 11/111 (pass code) is displayed, go to step 2). If no code is displayed, go to CIRCUIT TEST QA.

2) Check Throttle Linkage  Check throttle and linkage for sticking and binding. If throttle and linkage are okay, replace Throttle Position Sensor (TPS) and repeat QUICK TEST  . If throttle and linkage are binding, repair as necessary and repeat QUICK TEST.

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:

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