B1407

Code

ALFA ROMEO B — Body

Driver window closing circuit

Brand: ALFA ROMEO

Type: B — Body

Views: UK: 6 EN: 9 RU: 8

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Blown fuse or relays for power windows
Faulty driver window switch (stuck, intermittent contacts)
Failed window motor or worn brushes
Damaged wiring harness, broken wire or corroded connector in driver door harness (including pinched wires in the hinge area)
Faulty body control module / window control module
Water ingress or corrosion at connectors or in the switch assembly

Symptoms

Driver window will not close when commanded or stops before full close
Window moves slowly or intermittently in the close direction
Window reverses or opens unexpectedly when closing (anti-pinch behavior)
Stored B1407 fault and possibly related body control messages or warnings
Noise from motor or grinding when attempting to close

What to check

Retrieve and record all stored codes with a compatible scan tool, note freeze frame or live data during an operation
Visually inspect fuses and relays for power window circuits; check fuse continuity
Inspect driver door wiring harness, especially through the door hinge boot, for chafing, broken wires or corrosion
Check connectors at the switch, motor/regulator and control module for corrosion, bent pins or poor mating
Operate the driver window while observing connector terminals for voltage changes and secure connections
Listen for motor noise and feel for regulator movement; check for mechanical obstruction by moving the glass manually with power off (carefully)

Signal parameters

Battery voltage at rest: ~12.0–12.8 V; running ~13.5–14.5 V. Supply to motor when commanded should be near battery voltage.
Switch command signal: when switch is pressed for close/open the control input should change state (0 V to ~battery voltage or ground) — varies by vehicle architecture.
Motor supply under no-load run: typically draws 2–10 A; under load or stall current may exceed 15–30 A depending on motor. A sustained stall current is abnormal.
Position/limit sensor (if equipped) or anti-pinch feedback: typically a discrete state (open/closed) or resistance/voltage that changes at end-of-travel. Compare to factory values.

Diagnostic algorithm

Safety first — ensure ignition and power window operation is safe; support glass to prevent dropping during tests.
Scan for codes: read B1407 and any related codes. Clear codes and attempt to reproduce to verify persistence.
Check fuses/relays: verify continuity and that power is present at the window motor feed with ignition ON and while attempting to close the window.
Operate the switch while measuring voltage at the motor connector: verify motor supply polarity and voltage when close command given. If no voltage, trace back to switch and control module.
Inspect and wiggle the door harness in the hinge area while operating the switch to reveal intermittent wiring faults.
Test the driver window switch: measure switch outputs or substitute a known-good switch if available.
Bench test the motor by applying 12 V directly to the motor terminals (observe polarity for direction). If motor does not run or runs weakly/roughly, replace motor.
Measure motor current while operating. Excessive current can indicate regulator binding or a failing motor. If current is excessive, inspect/regreplace regulator or free the glass tracks.
Check ground integrity: measure voltage drop between motor ground and battery negative while operating; excessive drop indicates bad ground.
Inspect anti-pinch/limit sensor inputs (if equipped) and verify correct operation or continuity. Replace sensor/module if faulty.
If wiring and components test good but control signals from the body/window module are absent or erratic, test module outputs and inputs per factory procedure and consider module repair or replacement.
After repairs, clear codes and perform several full up/down cycles to confirm normal operation and no fault reoccurrence.

Likely causes

Intermittent or failed driver window switch
Corroded connector or damaged wiring in door harness (common at hinge boot)
Window motor starting to fail (high current draw or intermittent operation)
Mechanical regulator binding causing excessive motor load

Fault status

⚠️ Status

B1407 — Driver window closing circuit fault: the control module detected an abnormal or missing signal while commanding the driver window to close; action required to inspect switch, motor, wiring, and related sensors.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-1.5 hours

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