Normal Operation

WARNING: This page is about a different car, the 2010 Lincoln Town Car. However, it is still accessible from the selected car via links, so may be relevant.

The Liftgate/Trunk Module (LTM) receives voltage from the Central Junction Box (CJB) through circuits 640 (RD/YE) and 1524 (DB). The LTM is grounded through circuits 57 (BK) and 676 (PK/OG). The luggage compartment lid latch release module supplies voltage to the luggage compartment release solenoid through circuit 605 (RD). The LTM monitors the ajar switch.

The LTM receives vehicle speed information from the PCM. The LTM will shut down the system if vehicle speed is above 5 km/h (3 mph). For diagnostics, the module uses the ISO network. Whenever battery voltage is lost to the LTM, luggage compartment lid motor or the luggage compartment lid closing motor, the system must be initialized.

DTC B1551 Latch/Deck Lid Release Circuit Failure - Open, short to battery or overtemp condition (total current greater than 8 amps)
DTC B2421 VSS Stuck High - Vehicle speed greater than 3 mph during self-test, or vehicle speed signal always low when key in RUN/START (short to ground)
DTC C1123 Vehicle Speed Sensor Input Short to Battery - Vehicle speed signal high when key OFF and battery voltage is greater than 9 volts

This pinpoint test is intended to diagnose the following:

Fuse(s)
Wiring, terminals or connectors
Luggage compartment lid latch
LTM
PCM
Parking Aid Module (PAM)
Radio
Air suspension module