Diagnostic Aids
WARNING: This page does not describe the selected car, but rather 32 other vehicles, including the 2003 Mercury Sable, 2003 Mercury Mountaineer, 2003 Mercury Marauder, 2003 Mercury Grand Marquis, and 2003 Lincoln Town Car. However, it is still accessible from the selected car via links, so may be relevant.
Perform this test only when directed by QUICK TEST. This test is intended to diagnose the following:
- Wiring Harness Circuits (MAP SIG, SIG RTN & VREF)
- Faulty TMAP Sensor
- Faulty Powertrain Control Module (PCM)
VREF voltage should be 4-6 volts. BARO PID reading is in frequency/volts.
Fig 1: Identifying MAP Sensor Harness Connector Terminals (Aviator, Crown Victoria, Grand Marquis, LS, Marauder, Thunderbird & Town Car)