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 when instructed by QUICK TEST. This test is intended to diagnose the following:

Exhaust Gas Recirculation System Module (ESM).
Differential pressure feedback EGR sensor.
Differential pressure feedback EGR sensor pressure hoses.
Vacuum lines.
Harness circuits: VREF, DPFE, SIG, SIG RTN, EVR, EVR PWR.
Powertrain Control Module (PCM).

Fig 1: Identifying Exhaust Gas Recirculation System Components

Courtesy of FORD MOTOR CO.

For exhaust gas recirculation system connector terminal identification, see Fig 2.

Fig 2: Identifying MAP Sensor Harness Connector Terminals (Aviator, Crown Victoria, Grand Marquis, LS, Marauder, Thunderbird & Town Car)

Courtesy of FORD MOTOR CO.