B1555 on Lincoln
Tailgate/Liftgate/Boot/Trunk Position Sensor 4 — Signal Invalid (RGTM)
B1555 on Lincoln vehicles indicates tailgate/liftgate/boot/trunk position sensor 4 — signal invalid (rgtm). Au7o has documented this code across 1 Lincoln model — most commonly on Aviator. On power-liftgate vehicles the Rear Gate/Trunk Module (RGTM) sets B1555 when one of the liftgate position-sensor inputs returns an invalid/implausible signal, so the module can no longer trust its picture of where the gate is. Ford's SSM for 2020 Explorer/Aviator lists B1555 with B144D, B144E and B1556 as the code set produced by RGTM software wrongly sensing the liftgate ajar, and also documents B1555 being stored when water intrusion damages the right-hand power liftgate motor. Important scoping note: in Ford's older/legacy body-code list the same number B1555 is published as 'Ignition Run/Start Circuit Failure' for other modules — always read the code with the module that set it.
Common Causes of B1555
- •Outdated RGTM software (reprogram to latest level per Ford SSM)
- •Water intrusion into the right-hand power liftgate motor/drive unit
- •Failed liftgate position (Hall-effect) sensor or drive unit
- •Damaged liftgate wiring harness or corroded connector
- •Latch/ajar switch fault or misaligned striker
B1555 on Lincoln by Model
Lincoln Aviator(1 issue)
- Power-Liftgate Faults - Apply Ford SSM Symptom Split Before Parts2020-2022
Ford documents several distinct Aviator power-liftgate conditions. On some 2020-2022 vehicles, failure only through hands-free intelligent access or the outside handle while doors are locked can result from a poor connection at rear-keyless-entry connector C4332 below the striker (SSM 50810). Some 2020-2021 inoperative liftgates can involve RGTM software (SSM 49914). Early 2020 vehicles built on or before February 17, 2020, can partially open or trigger a false anti-theft alarm with B144D, B144E, B1555, or B1556 from RGTM software (SSM 49015). These bulletins do not diagnose every liftgate fault.
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View B1555 across all makes →Frequently Asked Questions
What does B1555 mean on Lincoln?▼
B1555 stands for "Tailgate/Liftgate/Boot/Trunk Position Sensor 4 — Signal Invalid (RGTM)." On power-liftgate vehicles the Rear Gate/Trunk Module (RGTM) sets B1555 when one of the liftgate position-sensor inputs returns an invalid/implausible signal, so the module can no longer trust its picture of where the gate is. Ford's SSM for 2020 Explorer/Aviator lists B1555 with B144D, B144E and B1556 as the code set produced by RGTM software wrongly sensing the liftgate ajar, and also documents B1555 being stored when water intrusion damages the right-hand power liftgate motor. Important scoping note: in Ford's older/legacy body-code list the same number B1555 is published as 'Ignition Run/Start Circuit Failure' for other modules — always read the code with the module that set it. On Lincoln specifically, this code is documented across 1 model.
What causes B1555 on Lincoln vehicles?▼
Common causes on Lincoln: Outdated RGTM software (reprogram to latest level per Ford SSM), Water intrusion into the right-hand power liftgate motor/drive unit, Failed liftgate position (Hall-effect) sensor or drive unit, Damaged liftgate wiring harness or corroded connector, Latch/ajar switch fault or misaligned striker. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix B1555 on a Lincoln?▼
Repair costs vary widely depending on the root cause and specific Lincoln model.
Which Lincoln models have B1555 documented?▼
Au7o has documented B1555 on 1 Lincoln model: Aviator.