Toggle Side Panel

Shopping Cart

No products in the basket.

Shopping Cart

No products in the basket.

Close search
Home / DTC / B1406 — Front left electric window lowering switch short to ground

B1406 — Front left electric window lowering switch short to ground

Detailed page for trouble code B1406.

34,405codes
59brands
11,914generic
22,491specific
All codes P-codes (Powertrain) B-codes (Body) C-codes (Chassis) U-codes (Network/User) Tesla Alerts
Reset
Code

B1406

ALFA ROMEO B — Body

Front left electric window lowering switch short to ground

Brand: ALFA ROMEO
Type: B — Body
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Damaged wiring with insulation breach contacting chassis ground
  • Defective front left window switch (internal short)
  • Corroded or bent connector terminals causing low-resistance path to ground
  • Faulty body control / window control module or grounding point
  • Water ingress in door causing short circuits

Symptoms

  • Front left window will not lower (or lower only intermittently)
  • Window control may be inoperative in the door switch but work from master switch (or vice versa)
  • Blown fuse or repeated fuse failures on the window circuit
  • Diagnostic trouble code B1406 present; possible abnormal behavior of other door electronics
  • Occasional clicking or lack of motor response when switching to lower

What to check

  • Verify stored freeze frame / live data for switch/wiring status with a scan tool
  • Inspect fuses and relays for the power window circuit
  • Visual inspection of door wiring harness through the door hinge boot for chafing
  • Check connector at the front left window switch for corrosion, moisture, or bent pins
  • Measure voltage at the switch connector with ignition ON (observe safety procedures)

Signal parameters

  • Battery voltage at switch power terminal: ~12–14 V with ignition/accessory ON
  • Switch output when not pressed: open/near battery voltage (depending on circuit design) — no direct 0 V to chassis ground
  • Short-to-ground condition: near 0 V or full continuity to chassis ground on the switch signal line
  • Motor current draw when operating: typically several amps (varies by motor); excessive current suggests mechanical bind or short
  • Resistance: continuity between the signal/return wire and chassis ground indicates short (low ohms)

Diagnostic algorithm

  1. Read and record freeze-frame and live data with a diagnostic scanner. Confirm B1406 and any related codes.
  2. Turn ignition OFF, remove the key, and disconnect battery negative if you will be unplugging connectors or accessing terminals.
  3. Visually inspect the door harness where it enters the body (rubber boot). Look for broken wires, pinching, or exposed conductors.
  4. Unplug the front left window switch connector. With ignition ON, measure voltage between the switch power terminal and ground to confirm supply voltage.
  5. With connector unplugged, check continuity between the suspected switch signal/ground wire and chassis ground. Low resistance indicates a short to ground.
  6. If short present at connector, isolate by back-probing or disconnecting sections of wiring (door vs body harness) to locate the short area (door harness, boot, or body side).
  7. Inspect and if necessary remove the switch from the door. Bench-test the switch for internal shorts using a multimeter across terminals while operating the switch.
  8. Repair damaged wiring (replace or solder and insulate, replace grommet/boot), clean/repair corroded connectors, or replace the switch assembly as indicated.
  9. After repair, clear codes and retest operation multiple cycles. Monitor for code return and verify proper window function.
  10. If wiring and switch check OK but code persists, test/inspect the body control/window module grounds and outputs; consider module fault and consult service manual for advanced testing.

Likely causes

  • Frayed or pinched harness where the door wiring passes through the hinge/boot
  • Short inside the switch assembly (common after spill or wear)
  • Connector plug at the switch has corrosion, bent pins or back-pin to ground
  • Aftermarket accessory or previous repair damaged the wiring
  • Poor/loose ground at door or body ground strap

Fault status

⚠️ Status
Front left power window lowering switch circuit: short to ground detected.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

B1405 B1407 B1408 B1409 B1410
89

Browse 89 ALFA ROMEO manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

ALFA ROMEO

Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

B1406

FIAT B — Body

Front left electric window lowering switch short to ground

Brand: FIAT
Type: B — Body
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Damaged wiring with insulation breach contacting chassis ground
  • Defective front left window switch (internal short)
  • Corroded or bent connector terminals causing low-resistance path to ground
  • Faulty body control / window control module or grounding point
  • Water ingress in door causing short circuits

Symptoms

  • Front left window will not lower (or lower only intermittently)
  • Window control may be inoperative in the door switch but work from master switch (or vice versa)
  • Blown fuse or repeated fuse failures on the window circuit
  • Diagnostic trouble code B1406 present; possible abnormal behavior of other door electronics
  • Occasional clicking or lack of motor response when switching to lower

What to check

  • Verify stored freeze frame / live data for switch/wiring status with a scan tool
  • Inspect fuses and relays for the power window circuit
  • Visual inspection of door wiring harness through the door hinge boot for chafing
  • Check connector at the front left window switch for corrosion, moisture, or bent pins
  • Measure voltage at the switch connector with ignition ON (observe safety procedures)

Signal parameters

  • Battery voltage at switch power terminal: ~12–14 V with ignition/accessory ON
  • Switch output when not pressed: open/near battery voltage (depending on circuit design) — no direct 0 V to chassis ground
  • Short-to-ground condition: near 0 V or full continuity to chassis ground on the switch signal line
  • Motor current draw when operating: typically several amps (varies by motor); excessive current suggests mechanical bind or short
  • Resistance: continuity between the signal/return wire and chassis ground indicates short (low ohms)

Diagnostic algorithm

  1. Read and record freeze-frame and live data with a diagnostic scanner. Confirm B1406 and any related codes.
  2. Turn ignition OFF, remove the key, and disconnect battery negative if you will be unplugging connectors or accessing terminals.
  3. Visually inspect the door harness where it enters the body (rubber boot). Look for broken wires, pinching, or exposed conductors.
  4. Unplug the front left window switch connector. With ignition ON, measure voltage between the switch power terminal and ground to confirm supply voltage.
  5. With connector unplugged, check continuity between the suspected switch signal/ground wire and chassis ground. Low resistance indicates a short to ground.
  6. If short present at connector, isolate by back-probing or disconnecting sections of wiring (door vs body harness) to locate the short area (door harness, boot, or body side).
  7. Inspect and if necessary remove the switch from the door. Bench-test the switch for internal shorts using a multimeter across terminals while operating the switch.
  8. Repair damaged wiring (replace or solder and insulate, replace grommet/boot), clean/repair corroded connectors, or replace the switch assembly as indicated.
  9. After repair, clear codes and retest operation multiple cycles. Monitor for code return and verify proper window function.
  10. If wiring and switch check OK but code persists, test/inspect the body control/window module grounds and outputs; consider module fault and consult service manual for advanced testing.

Likely causes

  • Frayed or pinched harness where the door wiring passes through the hinge/boot
  • Short inside the switch assembly (common after spill or wear)
  • Connector plug at the switch has corrosion, bent pins or back-pin to ground
  • Aftermarket accessory or previous repair damaged the wiring
  • Poor/loose ground at door or body ground strap

Fault status

⚠️ Status
Front left power window lowering switch circuit: short to ground detected.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

B1405 B1407 B1408 B1409 B1410
Repair manuals

Manual library for FIAT

26

Browse 26 FIAT manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

FIAT

Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

B1406

LAND ROVER B — Body

Auxiliary fuel heater

Brand: LAND ROVER
Type: B — Body
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Damaged wiring with insulation breach contacting chassis ground
  • Defective front left window switch (internal short)
  • Corroded or bent connector terminals causing low-resistance path to ground
  • Faulty body control / window control module or grounding point
  • Water ingress in door causing short circuits

Symptoms

  • Front left window will not lower (or lower only intermittently)
  • Window control may be inoperative in the door switch but work from master switch (or vice versa)
  • Blown fuse or repeated fuse failures on the window circuit
  • Diagnostic trouble code B1406 present; possible abnormal behavior of other door electronics
  • Occasional clicking or lack of motor response when switching to lower

What to check

  • Verify stored freeze frame / live data for switch/wiring status with a scan tool
  • Inspect fuses and relays for the power window circuit
  • Visual inspection of door wiring harness through the door hinge boot for chafing
  • Check connector at the front left window switch for corrosion, moisture, or bent pins
  • Measure voltage at the switch connector with ignition ON (observe safety procedures)

Signal parameters

  • Battery voltage at switch power terminal: ~12–14 V with ignition/accessory ON
  • Switch output when not pressed: open/near battery voltage (depending on circuit design) — no direct 0 V to chassis ground
  • Short-to-ground condition: near 0 V or full continuity to chassis ground on the switch signal line
  • Motor current draw when operating: typically several amps (varies by motor); excessive current suggests mechanical bind or short
  • Resistance: continuity between the signal/return wire and chassis ground indicates short (low ohms)

Diagnostic algorithm

  1. Read and record freeze-frame and live data with a diagnostic scanner. Confirm B1406 and any related codes.
  2. Turn ignition OFF, remove the key, and disconnect battery negative if you will be unplugging connectors or accessing terminals.
  3. Visually inspect the door harness where it enters the body (rubber boot). Look for broken wires, pinching, or exposed conductors.
  4. Unplug the front left window switch connector. With ignition ON, measure voltage between the switch power terminal and ground to confirm supply voltage.
  5. With connector unplugged, check continuity between the suspected switch signal/ground wire and chassis ground. Low resistance indicates a short to ground.
  6. If short present at connector, isolate by back-probing or disconnecting sections of wiring (door vs body harness) to locate the short area (door harness, boot, or body side).
  7. Inspect and if necessary remove the switch from the door. Bench-test the switch for internal shorts using a multimeter across terminals while operating the switch.
  8. Repair damaged wiring (replace or solder and insulate, replace grommet/boot), clean/repair corroded connectors, or replace the switch assembly as indicated.
  9. After repair, clear codes and retest operation multiple cycles. Monitor for code return and verify proper window function.
  10. If wiring and switch check OK but code persists, test/inspect the body control/window module grounds and outputs; consider module fault and consult service manual for advanced testing.

Likely causes

  • Frayed or pinched harness where the door wiring passes through the hinge/boot
  • Short inside the switch assembly (common after spill or wear)
  • Connector plug at the switch has corrosion, bent pins or back-pin to ground
  • Aftermarket accessory or previous repair damaged the wiring
  • Poor/loose ground at door or body ground strap

Fault status

⚠️ Status
Front left power window lowering switch circuit: short to ground detected.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

B1405 B1407 B1408 B1409 B1410
320

Browse 320 LAND ROVER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

LAND ROVER

Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

B1406

MITSUBISHI B — Body

FR analog G sensor fail

Brand: MITSUBISHI
Type: B — Body
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Damaged wiring with insulation breach contacting chassis ground
  • Defective front left window switch (internal short)
  • Corroded or bent connector terminals causing low-resistance path to ground
  • Faulty body control / window control module or grounding point
  • Water ingress in door causing short circuits

Symptoms

  • Front left window will not lower (or lower only intermittently)
  • Window control may be inoperative in the door switch but work from master switch (or vice versa)
  • Blown fuse or repeated fuse failures on the window circuit
  • Diagnostic trouble code B1406 present; possible abnormal behavior of other door electronics
  • Occasional clicking or lack of motor response when switching to lower

What to check

  • Verify stored freeze frame / live data for switch/wiring status with a scan tool
  • Inspect fuses and relays for the power window circuit
  • Visual inspection of door wiring harness through the door hinge boot for chafing
  • Check connector at the front left window switch for corrosion, moisture, or bent pins
  • Measure voltage at the switch connector with ignition ON (observe safety procedures)

Signal parameters

  • Battery voltage at switch power terminal: ~12–14 V with ignition/accessory ON
  • Switch output when not pressed: open/near battery voltage (depending on circuit design) — no direct 0 V to chassis ground
  • Short-to-ground condition: near 0 V or full continuity to chassis ground on the switch signal line
  • Motor current draw when operating: typically several amps (varies by motor); excessive current suggests mechanical bind or short
  • Resistance: continuity between the signal/return wire and chassis ground indicates short (low ohms)

Diagnostic algorithm

  1. Read and record freeze-frame and live data with a diagnostic scanner. Confirm B1406 and any related codes.
  2. Turn ignition OFF, remove the key, and disconnect battery negative if you will be unplugging connectors or accessing terminals.
  3. Visually inspect the door harness where it enters the body (rubber boot). Look for broken wires, pinching, or exposed conductors.
  4. Unplug the front left window switch connector. With ignition ON, measure voltage between the switch power terminal and ground to confirm supply voltage.
  5. With connector unplugged, check continuity between the suspected switch signal/ground wire and chassis ground. Low resistance indicates a short to ground.
  6. If short present at connector, isolate by back-probing or disconnecting sections of wiring (door vs body harness) to locate the short area (door harness, boot, or body side).
  7. Inspect and if necessary remove the switch from the door. Bench-test the switch for internal shorts using a multimeter across terminals while operating the switch.
  8. Repair damaged wiring (replace or solder and insulate, replace grommet/boot), clean/repair corroded connectors, or replace the switch assembly as indicated.
  9. After repair, clear codes and retest operation multiple cycles. Monitor for code return and verify proper window function.
  10. If wiring and switch check OK but code persists, test/inspect the body control/window module grounds and outputs; consider module fault and consult service manual for advanced testing.

Likely causes

  • Frayed or pinched harness where the door wiring passes through the hinge/boot
  • Short inside the switch assembly (common after spill or wear)
  • Connector plug at the switch has corrosion, bent pins or back-pin to ground
  • Aftermarket accessory or previous repair damaged the wiring
  • Poor/loose ground at door or body ground strap

Fault status

⚠️ Status
Front left power window lowering switch circuit: short to ground detected.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

B1405 B1407 B1408 B1409 B1410
406

Browse 406 MITSUBISHI manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

MITSUBISHI

Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

B1406

Other B — Body

Driver Power Window Down Circuit Short To Ground

Brand: Other
Type: B — Body
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Damaged wiring with insulation breach contacting chassis ground
  • Defective front left window switch (internal short)
  • Corroded or bent connector terminals causing low-resistance path to ground
  • Faulty body control / window control module or grounding point
  • Water ingress in door causing short circuits

Symptoms

  • Front left window will not lower (or lower only intermittently)
  • Window control may be inoperative in the door switch but work from master switch (or vice versa)
  • Blown fuse or repeated fuse failures on the window circuit
  • Diagnostic trouble code B1406 present; possible abnormal behavior of other door electronics
  • Occasional clicking or lack of motor response when switching to lower

What to check

  • Verify stored freeze frame / live data for switch/wiring status with a scan tool
  • Inspect fuses and relays for the power window circuit
  • Visual inspection of door wiring harness through the door hinge boot for chafing
  • Check connector at the front left window switch for corrosion, moisture, or bent pins
  • Measure voltage at the switch connector with ignition ON (observe safety procedures)

Signal parameters

  • Battery voltage at switch power terminal: ~12–14 V with ignition/accessory ON
  • Switch output when not pressed: open/near battery voltage (depending on circuit design) — no direct 0 V to chassis ground
  • Short-to-ground condition: near 0 V or full continuity to chassis ground on the switch signal line
  • Motor current draw when operating: typically several amps (varies by motor); excessive current suggests mechanical bind or short
  • Resistance: continuity between the signal/return wire and chassis ground indicates short (low ohms)

Diagnostic algorithm

  1. Read and record freeze-frame and live data with a diagnostic scanner. Confirm B1406 and any related codes.
  2. Turn ignition OFF, remove the key, and disconnect battery negative if you will be unplugging connectors or accessing terminals.
  3. Visually inspect the door harness where it enters the body (rubber boot). Look for broken wires, pinching, or exposed conductors.
  4. Unplug the front left window switch connector. With ignition ON, measure voltage between the switch power terminal and ground to confirm supply voltage.
  5. With connector unplugged, check continuity between the suspected switch signal/ground wire and chassis ground. Low resistance indicates a short to ground.
  6. If short present at connector, isolate by back-probing or disconnecting sections of wiring (door vs body harness) to locate the short area (door harness, boot, or body side).
  7. Inspect and if necessary remove the switch from the door. Bench-test the switch for internal shorts using a multimeter across terminals while operating the switch.
  8. Repair damaged wiring (replace or solder and insulate, replace grommet/boot), clean/repair corroded connectors, or replace the switch assembly as indicated.
  9. After repair, clear codes and retest operation multiple cycles. Monitor for code return and verify proper window function.
  10. If wiring and switch check OK but code persists, test/inspect the body control/window module grounds and outputs; consider module fault and consult service manual for advanced testing.

Likely causes

  • Frayed or pinched harness where the door wiring passes through the hinge/boot
  • Short inside the switch assembly (common after spill or wear)
  • Connector plug at the switch has corrosion, bent pins or back-pin to ground
  • Aftermarket accessory or previous repair damaged the wiring
  • Poor/loose ground at door or body ground strap

Fault status

⚠️ Status
Front left power window lowering switch circuit: short to ground detected.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

B1405 B1407 B1408 B1409 B1410
7,894

The library contains 7,894 repair and diagnostic manuals. Choose a brand to open the full manual tree by year, model and trim.

ALFA ROMEO
89
AUDI
1,160
BMW
479
CHEVROLET
212
DAEWOO
75
FIAT
26
GENESIS
207
HUMMER
138
HYUNDAI
371
ISUZU
86
LAND ROVER
320
LEXUS
280
LINCOLN
166
MERCEDES-BENZ
856
MERCURY
296
MITSUBISHI
406
PORSCHE
136
TESLA
58
TOYOTA
2,042
TRIUMPH
131
VOLKSWAGEN
139
VOLVO
221
Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email

Report

Harassment or bullying behavior
Contains mature or sensitive content
Contains misleading or false information
Contains abusive or derogatory content
Contains spam, fake content or potential malware

Block Member?

Please confirm you want to block this member.

You will no longer be able to:

  • See blocked member's posts
  • Mention this member in posts
  • Invite this member to groups
  • Message this member
  • Add this member as a connection

Please note: This action will also remove this member from your connections and send a report to the site admin. Please allow a few minutes for this process to complete.

Report

You have already reported this .