B1418

Code

ALFA ROMEO B — Body

Front right electric window motor circuit

Brand: ALFA ROMEO

Type: B — Body

Views: UK: 4 EN: 7 RU: 4

AI status

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Page language: EN

Causes

Damaged or disconnected wiring harness to front right window motor
Corroded/loose connector or pins at motor or door module
Blown fuse or faulty relay protecting the window circuit
Failed front right window motor (internal fault or seized gears)
Faulty window switch (driver or passenger)
Faulty door module / body control module output stage

Symptoms

Front right window inoperative or works intermittently
No sound from motor when switch is pressed or relay operated
Clicking from relay/BCM but motor does not turn
Slow window movement or stops under load
Diagnostic trouble code B1418 stored in BCM or door module
Possible burning smell or heat at connector or motor in severe cases

What to check

Read and record freeze-frame data and stored fault info with an OEM or full-function scan tool
Attempt window operation from both driver master switch and passenger switch while observing behavior
Visually inspect wiring and connectors at the front right door, motor and door module for corrosion, water, pin damage or loose terminals
Check relevant fuses and relays for continuity and correct rating
Check for module communication errors on the bus (CAN) using a scan tool
Listen for motor noise when switch commanded — no sound suggests open circuit or module failure; humming suggests high current/stall

Signal parameters

Battery supply at motor connector when idle: ~0 V (switch off)
Battery supply at motor connector when commanded: close to battery voltage (~11.5–14.5 V) on one pin and near 0 V on the opposite pin (polarity depends on up/down command)
Motor coil DC resistance (typical): low value — usually sub-1 to a few ohms (model-dependent). Very high or infinite indicates open winding
Stall current: can be high (single‑digit to tens of amps). Expect significant current when motor is stalled — use clamp meter for measurement
Control output type: often low-side or H-bridge driver; when PWM-controlled expect switching frequency in the 50–400 Hz range (model dependent)
Expected waveform: clean switching or solid supply to motor; noise, irregular pulses or no switching indicates driver or wiring issue

Diagnostic algorithm

Safety first: park vehicle, engage parking brake and disable ignition as required. Be cautious when powering motors during tests.
Read and record all stored codes and live data from the BCM/door module. Note freeze-frame and occurrence count.
Attempt to operate front right window while observing live data (current draw, output states) with a scan tool. Note whether driver and passenger switch inputs are seen by module.
Check fuses and relays for the windows circuit; replace if faulty and retest.
Perform a visual inspection of the door harness, protective grommet and connectors for damage, corrosion or pin push-out. Repair or replace damaged components.
With ignition on, measure DC voltage at the motor connector while operating the switch: verify battery presence and polarity reversal for up/down commands. If no voltage, proceed to step 7.
If voltage present but motor does not run, measure current with a clamp meter at motor supply while commanding operation. High or zero current indicates motor stall or open circuit; remove door trim and bench-test motor directly with fused jumper to battery to confirm motor condition (bench test briefly to avoid damage).
If no voltage at motor connector when commanded, backprobe output at door module/BCM connector and the switch. Check continuity between module and motor connector; repair any open/short.
Inspect and test switch operation and continuity. Swap with known-good switch if available.
If wiring and switch OK but no proper driver output, suspect door module/BCM output stage. Confirm module supply and ground rails, then follow OEM module diagnostics. Reflash or replace module only after confirming wiring and motor integrity.
After repair, clear codes and perform several full up/down cycles to confirm operation and that B1418 does not return.
Notes: when bench-testing motors apply a series fuse or circuit breaker and observe safety precautions. Avoid prolonged stall testing to prevent overheating.

Likely causes

Open or short in the motor supply or ground conductors
Corroded motor connector or pushed-out pin causing intermittent contact
Motor stalled or drawing excessive current due to seized regulator or debris
Faulty driver transistor inside door module (short to supply/ground)
Blown fuse protecting the window circuit

Fault status

⚠️ Status

Stored fault: Front-right electric window motor circuit. The control module has detected an electrical fault (open, short, high current or communication failure) while commanding the front right window motor. Inspect wiring, connectors, fuses, motor and door/module outputs.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5–2.0 hours

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