B1399

Code

Other B — Body

Driver Power Window One Touch Window Relay Circuit Open

Brand: Other

Type: B — Body

Views: UK: 26 EN: 40 RU: 40

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Page language: EN

Blown fuse for power windows or relay coil
Faulty one-touch relay (stuck open or internally open)
Open or high-resistance wiring between relay, switch and body control module (BCM)
Corroded/loose connector or terminal at relay, switch or BCM
Faulty driver door master switch or window motor (overcurrent protection open)
Body control module / window control module failure or missing ground reference

Scan for B1399 and any related body/control module codes with a compatible scanner
Verify battery voltage (12V+) and good ground before testing
Visually inspect fuses related to power windows and BCM; check relay socket for signs of corrosion or heat
Listen for relay click when commanding one-touch; try manual switch and observe behavior
Wiggle test harness and connectors at driver door, relay pack, and BCM while operating switch to look for intermittent change
Measure continuity/voltage at relay coil terminals and at BCM/relay connector pins

Battery supply to relay coil: ~12 V with ignition/accessory on when one-touch is commanded
Relay coil ground: near 0 V when energized (closed path to chassis or BCM control)
Control command from BCM/master switch: 0–12 V or switched ground depending on vehicle design
Coil resistance: typical small relay coil ~50–200 ohms (manufacturer specific)
Switch input/output signals: logical command present at master switch when pressed (refer to scan tool data)

Confirm code presence and freeze frame with scan tool; clear code and attempt to reproduce
Check related fuses and replace any blown fuses; retest one-touch function
Attempt to operate one-touch while listening for relay click. If no click, probe relay coil supply pin for battery + with accessory/ignition on
If coil supply is present but coil has no ground when commanded, backprobe BCM or switch control pin for the control signal while operating one-touch
If coil ground/control is missing, inspect wiring for open, broken pins, or corrosion between relay, switch and BCM; repair wiring as needed
If coil supply absent, trace back to fuse, ignition/ACC feed, or fusible link; repair wiring or replace fuse source component
If coil supply and control signal are correct but relay does not click, remove relay and bench-test or swap with known-good identical relay; replace relay if failed
If relay and wiring check good but symptom persists, bench-test driver master switch and window motor circuits per service manual; replace faulty switch or control module as indicated
After repairs, clear codes and verify one-touch function over multiple cycles; re-scan to ensure B1399 does not return