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Home / DTC / B1434 — Wiper speed relay coil

B1434 — Wiper speed relay coil

Detailed page for trouble code B1434.

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22,491specific
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Code

B1434

ALFA ROMEO B — Body

Wiper speed relay coil

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

Causes

  • Faulty wiper speed relay (coil open or shorted)
  • Corroded or loose relay socket/connector
  • Broken, shorted or high-resistance wiring in relay coil circuit
  • Poor or missing ground at relay/BCM
  • Water ingress/corrosion at relay or connectors
  • Wiper motor jam or excessive mechanical load causing relay stress

Symptoms

  • Wipers do not operate at one or more speeds
  • Wipers operate only intermittently or only on one speed
  • Clicking noise from relay socket or no click when switching speeds
  • Blown fuse(s) for wiper circuit (if short present)
  • Wipers stop working when under load or after extended use

What to check

  • Read and record B1434 and any other stored codes with a scan tool; note freeze-frame/state
  • Visual inspection of relay, relay socket and wiring for corrosion, damage or water entry
  • Check related fuses and replace if blown; inspect fuse holder for corrosion
  • Listen for relay click while operating wiper switch at each speed
  • Swap the suspect relay with a known-good identical relay (if available) to see if behavior changes
  • Measure coil resistance of the relay (relay removed) with DMM and compare to specification or a known-good relay

Signal parameters

  • Coil supply voltage when energized: ~11–14 V (vehicle battery voltage)
  • Typical relay coil resistance (generic automotive): ~30–200 Ω (varies by relay design) — compare to OEM spec or a known-good relay
  • Coil current when energized: typically ~60–400 mA (depends on coil resistance)
  • Control signal: switched 0 V/12 V or PWM from BCM depending on vehicle; expect clear change when switching speeds

Diagnostic algorithm

  1. Scan: read B1434 and additional codes; record vehicle conditions when code set.
  2. Inspect: visually inspect relay, socket, wiring harness, connectors, and ground points for corrosion, damage or water ingress; repair as needed.
  3. Fuses: check and confirm related fuses are intact and contacts are clean.
  4. Relay swap: with ignition off, swap relay with identical known-good relay (same part number) and operate wipers to check for change in behavior.
  5. Measure relay coil resistance: remove relay and measure coil ohms; compare to OEM spec or known-good relay. If open/shorted, replace relay.
  6. Energize test: with relay installed, back-probe coil terminals while operating switch and verify coil receives battery voltage and that the control side switches to ground (or vice versa).
  7. Wiring/continuity: if coil does not receive proper voltage or control, trace wiring to BCM/switch and check continuity and resistance; repair broken or shorted wires.
  8. Ground check: verify solid ground at relay/BCM; clean and tighten ground connections.
  9. Wiper motor load: check motor operation and draw. If motor is seizing or drawing excessive current, repair or replace motor before replacing relay again.
  10. BCM output test: if wiring and relay are good but coil control is absent or abnormal, test/replace body control module or its relay driver per factory procedures.
  11. Clear codes and retest wiper operation under various speeds and conditions to confirm repair.

Likely causes

  • Defective wiper speed relay coil
  • Corroded connector or poor terminal contact at relay socket
  • Open or short in supply or ground wiring to the relay coil

Fault status

⚠️ Status
Wiper speed relay coil circuit malfunction detected — possible open/short or poor connection; may cause loss of one or more wiper speeds.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

B1430 B1435 B1440 P0562 U0121
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

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Code

B1434

FIAT B — Body

Wiper speed relay coil

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

Causes

  • Faulty wiper speed relay (coil open or shorted)
  • Corroded or loose relay socket/connector
  • Broken, shorted or high-resistance wiring in relay coil circuit
  • Poor or missing ground at relay/BCM
  • Water ingress/corrosion at relay or connectors
  • Wiper motor jam or excessive mechanical load causing relay stress

Symptoms

  • Wipers do not operate at one or more speeds
  • Wipers operate only intermittently or only on one speed
  • Clicking noise from relay socket or no click when switching speeds
  • Blown fuse(s) for wiper circuit (if short present)
  • Wipers stop working when under load or after extended use

What to check

  • Read and record B1434 and any other stored codes with a scan tool; note freeze-frame/state
  • Visual inspection of relay, relay socket and wiring for corrosion, damage or water entry
  • Check related fuses and replace if blown; inspect fuse holder for corrosion
  • Listen for relay click while operating wiper switch at each speed
  • Swap the suspect relay with a known-good identical relay (if available) to see if behavior changes
  • Measure coil resistance of the relay (relay removed) with DMM and compare to specification or a known-good relay

Signal parameters

  • Coil supply voltage when energized: ~11–14 V (vehicle battery voltage)
  • Typical relay coil resistance (generic automotive): ~30–200 Ω (varies by relay design) — compare to OEM spec or a known-good relay
  • Coil current when energized: typically ~60–400 mA (depends on coil resistance)
  • Control signal: switched 0 V/12 V or PWM from BCM depending on vehicle; expect clear change when switching speeds

Diagnostic algorithm

  1. Scan: read B1434 and additional codes; record vehicle conditions when code set.
  2. Inspect: visually inspect relay, socket, wiring harness, connectors, and ground points for corrosion, damage or water ingress; repair as needed.
  3. Fuses: check and confirm related fuses are intact and contacts are clean.
  4. Relay swap: with ignition off, swap relay with identical known-good relay (same part number) and operate wipers to check for change in behavior.
  5. Measure relay coil resistance: remove relay and measure coil ohms; compare to OEM spec or known-good relay. If open/shorted, replace relay.
  6. Energize test: with relay installed, back-probe coil terminals while operating switch and verify coil receives battery voltage and that the control side switches to ground (or vice versa).
  7. Wiring/continuity: if coil does not receive proper voltage or control, trace wiring to BCM/switch and check continuity and resistance; repair broken or shorted wires.
  8. Ground check: verify solid ground at relay/BCM; clean and tighten ground connections.
  9. Wiper motor load: check motor operation and draw. If motor is seizing or drawing excessive current, repair or replace motor before replacing relay again.
  10. BCM output test: if wiring and relay are good but coil control is absent or abnormal, test/replace body control module or its relay driver per factory procedures.
  11. Clear codes and retest wiper operation under various speeds and conditions to confirm repair.

Likely causes

  • Defective wiper speed relay coil
  • Corroded connector or poor terminal contact at relay socket
  • Open or short in supply or ground wiring to the relay coil

Fault status

⚠️ Status
Wiper speed relay coil circuit malfunction detected — possible open/short or poor connection; may cause loss of one or more wiper speeds.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

B1430 B1435 B1440 P0562 U0121
Repair manuals

Manual library for FIAT

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Code

B1434

LAND ROVER B — Body

Face of the front distribution engine

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

Causes

  • Faulty wiper speed relay (coil open or shorted)
  • Corroded or loose relay socket/connector
  • Broken, shorted or high-resistance wiring in relay coil circuit
  • Poor or missing ground at relay/BCM
  • Water ingress/corrosion at relay or connectors
  • Wiper motor jam or excessive mechanical load causing relay stress

Symptoms

  • Wipers do not operate at one or more speeds
  • Wipers operate only intermittently or only on one speed
  • Clicking noise from relay socket or no click when switching speeds
  • Blown fuse(s) for wiper circuit (if short present)
  • Wipers stop working when under load or after extended use

What to check

  • Read and record B1434 and any other stored codes with a scan tool; note freeze-frame/state
  • Visual inspection of relay, relay socket and wiring for corrosion, damage or water entry
  • Check related fuses and replace if blown; inspect fuse holder for corrosion
  • Listen for relay click while operating wiper switch at each speed
  • Swap the suspect relay with a known-good identical relay (if available) to see if behavior changes
  • Measure coil resistance of the relay (relay removed) with DMM and compare to specification or a known-good relay

Signal parameters

  • Coil supply voltage when energized: ~11–14 V (vehicle battery voltage)
  • Typical relay coil resistance (generic automotive): ~30–200 Ω (varies by relay design) — compare to OEM spec or a known-good relay
  • Coil current when energized: typically ~60–400 mA (depends on coil resistance)
  • Control signal: switched 0 V/12 V or PWM from BCM depending on vehicle; expect clear change when switching speeds

Diagnostic algorithm

  1. Scan: read B1434 and additional codes; record vehicle conditions when code set.
  2. Inspect: visually inspect relay, socket, wiring harness, connectors, and ground points for corrosion, damage or water ingress; repair as needed.
  3. Fuses: check and confirm related fuses are intact and contacts are clean.
  4. Relay swap: with ignition off, swap relay with identical known-good relay (same part number) and operate wipers to check for change in behavior.
  5. Measure relay coil resistance: remove relay and measure coil ohms; compare to OEM spec or known-good relay. If open/shorted, replace relay.
  6. Energize test: with relay installed, back-probe coil terminals while operating switch and verify coil receives battery voltage and that the control side switches to ground (or vice versa).
  7. Wiring/continuity: if coil does not receive proper voltage or control, trace wiring to BCM/switch and check continuity and resistance; repair broken or shorted wires.
  8. Ground check: verify solid ground at relay/BCM; clean and tighten ground connections.
  9. Wiper motor load: check motor operation and draw. If motor is seizing or drawing excessive current, repair or replace motor before replacing relay again.
  10. BCM output test: if wiring and relay are good but coil control is absent or abnormal, test/replace body control module or its relay driver per factory procedures.
  11. Clear codes and retest wiper operation under various speeds and conditions to confirm repair.

Likely causes

  • Defective wiper speed relay coil
  • Corroded connector or poor terminal contact at relay socket
  • Open or short in supply or ground wiring to the relay coil

Fault status

⚠️ Status
Wiper speed relay coil circuit malfunction detected — possible open/short or poor connection; may cause loss of one or more wiper speeds.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

B1430 B1435 B1440 P0562 U0121
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

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+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
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Code

B1434

MITSUBISHI B — Body

FL side ABG active circuit short

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

Causes

  • Faulty wiper speed relay (coil open or shorted)
  • Corroded or loose relay socket/connector
  • Broken, shorted or high-resistance wiring in relay coil circuit
  • Poor or missing ground at relay/BCM
  • Water ingress/corrosion at relay or connectors
  • Wiper motor jam or excessive mechanical load causing relay stress

Symptoms

  • Wipers do not operate at one or more speeds
  • Wipers operate only intermittently or only on one speed
  • Clicking noise from relay socket or no click when switching speeds
  • Blown fuse(s) for wiper circuit (if short present)
  • Wipers stop working when under load or after extended use

What to check

  • Read and record B1434 and any other stored codes with a scan tool; note freeze-frame/state
  • Visual inspection of relay, relay socket and wiring for corrosion, damage or water entry
  • Check related fuses and replace if blown; inspect fuse holder for corrosion
  • Listen for relay click while operating wiper switch at each speed
  • Swap the suspect relay with a known-good identical relay (if available) to see if behavior changes
  • Measure coil resistance of the relay (relay removed) with DMM and compare to specification or a known-good relay

Signal parameters

  • Coil supply voltage when energized: ~11–14 V (vehicle battery voltage)
  • Typical relay coil resistance (generic automotive): ~30–200 Ω (varies by relay design) — compare to OEM spec or a known-good relay
  • Coil current when energized: typically ~60–400 mA (depends on coil resistance)
  • Control signal: switched 0 V/12 V or PWM from BCM depending on vehicle; expect clear change when switching speeds

Diagnostic algorithm

  1. Scan: read B1434 and additional codes; record vehicle conditions when code set.
  2. Inspect: visually inspect relay, socket, wiring harness, connectors, and ground points for corrosion, damage or water ingress; repair as needed.
  3. Fuses: check and confirm related fuses are intact and contacts are clean.
  4. Relay swap: with ignition off, swap relay with identical known-good relay (same part number) and operate wipers to check for change in behavior.
  5. Measure relay coil resistance: remove relay and measure coil ohms; compare to OEM spec or known-good relay. If open/shorted, replace relay.
  6. Energize test: with relay installed, back-probe coil terminals while operating switch and verify coil receives battery voltage and that the control side switches to ground (or vice versa).
  7. Wiring/continuity: if coil does not receive proper voltage or control, trace wiring to BCM/switch and check continuity and resistance; repair broken or shorted wires.
  8. Ground check: verify solid ground at relay/BCM; clean and tighten ground connections.
  9. Wiper motor load: check motor operation and draw. If motor is seizing or drawing excessive current, repair or replace motor before replacing relay again.
  10. BCM output test: if wiring and relay are good but coil control is absent or abnormal, test/replace body control module or its relay driver per factory procedures.
  11. Clear codes and retest wiper operation under various speeds and conditions to confirm repair.

Likely causes

  • Defective wiper speed relay coil
  • Corroded connector or poor terminal contact at relay socket
  • Open or short in supply or ground wiring to the relay coil

Fault status

⚠️ Status
Wiper speed relay coil circuit malfunction detected — possible open/short or poor connection; may cause loss of one or more wiper speeds.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

B1430 B1435 B1440 P0562 U0121
406

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

MITSUBISHI

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

B1434

Other B — Body

Wiper Hi/Low Speed Relay Coil Circuit Failure

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

Causes

  • Faulty wiper speed relay (coil open or shorted)
  • Corroded or loose relay socket/connector
  • Broken, shorted or high-resistance wiring in relay coil circuit
  • Poor or missing ground at relay/BCM
  • Water ingress/corrosion at relay or connectors
  • Wiper motor jam or excessive mechanical load causing relay stress

Symptoms

  • Wipers do not operate at one or more speeds
  • Wipers operate only intermittently or only on one speed
  • Clicking noise from relay socket or no click when switching speeds
  • Blown fuse(s) for wiper circuit (if short present)
  • Wipers stop working when under load or after extended use

What to check

  • Read and record B1434 and any other stored codes with a scan tool; note freeze-frame/state
  • Visual inspection of relay, relay socket and wiring for corrosion, damage or water entry
  • Check related fuses and replace if blown; inspect fuse holder for corrosion
  • Listen for relay click while operating wiper switch at each speed
  • Swap the suspect relay with a known-good identical relay (if available) to see if behavior changes
  • Measure coil resistance of the relay (relay removed) with DMM and compare to specification or a known-good relay

Signal parameters

  • Coil supply voltage when energized: ~11–14 V (vehicle battery voltage)
  • Typical relay coil resistance (generic automotive): ~30–200 Ω (varies by relay design) — compare to OEM spec or a known-good relay
  • Coil current when energized: typically ~60–400 mA (depends on coil resistance)
  • Control signal: switched 0 V/12 V or PWM from BCM depending on vehicle; expect clear change when switching speeds

Diagnostic algorithm

  1. Scan: read B1434 and additional codes; record vehicle conditions when code set.
  2. Inspect: visually inspect relay, socket, wiring harness, connectors, and ground points for corrosion, damage or water ingress; repair as needed.
  3. Fuses: check and confirm related fuses are intact and contacts are clean.
  4. Relay swap: with ignition off, swap relay with identical known-good relay (same part number) and operate wipers to check for change in behavior.
  5. Measure relay coil resistance: remove relay and measure coil ohms; compare to OEM spec or known-good relay. If open/shorted, replace relay.
  6. Energize test: with relay installed, back-probe coil terminals while operating switch and verify coil receives battery voltage and that the control side switches to ground (or vice versa).
  7. Wiring/continuity: if coil does not receive proper voltage or control, trace wiring to BCM/switch and check continuity and resistance; repair broken or shorted wires.
  8. Ground check: verify solid ground at relay/BCM; clean and tighten ground connections.
  9. Wiper motor load: check motor operation and draw. If motor is seizing or drawing excessive current, repair or replace motor before replacing relay again.
  10. BCM output test: if wiring and relay are good but coil control is absent or abnormal, test/replace body control module or its relay driver per factory procedures.
  11. Clear codes and retest wiper operation under various speeds and conditions to confirm repair.

Likely causes

  • Defective wiper speed relay coil
  • Corroded connector or poor terminal contact at relay socket
  • Open or short in supply or ground wiring to the relay coil

Fault status

⚠️ Status
Wiper speed relay coil circuit malfunction detected — possible open/short or poor connection; may cause loss of one or more wiper speeds.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

B1430 B1435 B1440 P0562 U0121
8,969

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