B1563

Code

Other B — Body

Door Ajar Circuit Failure

Brand: Other

Type: B — Body

Views: UK: 29 EN: 55 RU: 28

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Read codes and live data with a capable scan tool; note which door input is flagged
Visual inspection of door latch, switch, harness, and connectors for damage or corrosion
Wiggle test wiring at hinge while monitoring live data for intermittent changes
Backprobe the switch connector and measure voltage with door open/closed
Perform continuity/resistance checks from latch connector to BCM harness connector
Check for water, dirt or foreign objects in the latch/switch area

Typical door-ajar input is a switched circuit to BCM with either pull-up (to 5 V or battery) or pull-down; states are either near 0 V (closed) or near pull-up voltage (open) depending on design
Closed-switch resistance: near 0 ohms (low resistance)
Open-switch resistance: high/OL (open circuit)
Nominal input voltage ranges to expect: ~0–1 V for a grounded input, or ~4–5 V (logic) or ~12 V (battery-referenced) for an open state — consult vehicle wiring diagram
Very low current draw in idle state; short to ground or battery will change voltage and current significantly

Connect a scan tool, confirm B1563 and identify which door circuit is affected; record live status while opening/closing that door.
Perform a visual inspection of the door hinge area, wiring looms, and latch assembly for damage, pinching or corrosion. Repair obvious wiring damage.
With the door in the reported state, backprobe the latch/switch connector and measure voltage between signal and ground with door open and closed. Compare to expected logic levels from the service manual.
Check switch continuity/resistance directly (unplugged) while actuating latch: closed ~0 Ω, open infinite. Replace switch/latch if readings are out of spec.
If voltages or continuity are abnormal at the latch connector, trace the harness to the body connector and BCM. Perform continuity and resistance checks to the BCM input pins. Repair any open/shorts.
Inspect and clean connectors and terminals; apply dielectric grease if appropriate and reassemble securely.
If wiring and switch check good but fault persists, inspect for shorts to battery or ground and for interference from aftermarket devices.
As a last step, if all wiring and components test correctly, consult manufacturer diagnostics for BCM input tests; consider BCM repair/reprogramming or replacement per factory procedure.
Clear codes and verify proper operation over several open/close cycles and after a road test to confirm repair.