Code
B1438
ALFA ROMEO
B — Body
Wiper activation switch circuit
Views:
UK: 5
EN: 7
RU: 5
AI status
Completed
Completed
100%
Causes
- Faulty wiper/washer activation switch
- Damaged or corroded connector(s) at switch or BCM
- Broken or shorted wiring between switch and BCM
- Blown fuse or faulty wiper relay (if applicable)
- Faulty body control module (rare)
Symptoms
- Wipers do not operate or operate intermittently
- Cannot select wiper speeds or intermittent function fails
- Wipers stuck in one position or park function fails
- Erratic wiper behavior (unexpected start/stop)
- Possible related dash message or lamp (BCM fault indicator)
What to check
- Read and record freeze-frame and live data using a diagnostic scanner (wiper switch positions/inputs).
- Visually inspect switch, connectors and wiring harness for damage, corrosion, water ingress or pin deformation.
- Check related fuses and relays for continuity/power.
- Perform continuity and resistance checks on switch circuits (switch to BCM) with connector disconnected.
- Backprobe switch connector with ignition on and operate switch to confirm expected signals/voltages.
- Wiggle test harness while observing live data for intermittent faults.
Signal parameters
- Battery voltage present at switch supply with ignition ON: approx. 11–14 V
- Switch closed continuity: near 0 Ω between relevant pins when engaged; open/infinite when released
- Switch outputs to BCM: expected discrete logic states (ground or battery) or pulsed signals depending on position — verify with oscilloscope or scan tool live data
- Resistance of internal switch contacts may rise when worn: compare to known-good spec where available
- Voltage drop on ground circuits should be minimal (
Diagnostic algorithm
- Connect a diagnostic scanner, read DTCs and live data. Confirm B1438 presence and note any related codes.
- Inspect fuses, relays and visual condition of wiper switch and harness (look for water, corrosion, pin damage).
- With ignition ON, backprobe switch connector and observe voltages while operating each switch position. Compare to expected supply and logic levels.
- Verify continuity between switch signal pins and BCM pins. Check for shorts to ground or battery using multimeter (resistance/voltage tests).
- Perform wiggle test on harness and switch while monitoring live data to find intermittent opens or shorts.
- If wiring and connectors are good, bench-test or substitute a known-good wiper switch to confirm fault follows switch.
- If replacement switch does not clear fault, inspect BCM connector pins and grounds. Check for BCM software updates or intermittent BCM faults.
- After repairs, clear codes and retest all switch positions and wiper functions for correct operation and absence of B1438.
Likely causes
- Intermittent/open circuit in switch harness (pin corrosion, broken wire)
- Short to battery or ground on one of the switch signal wires
- Switch internal contact wear/failure causing unstable signals
- Poor ground at switch or BCM
- Moisture intrusion in switch assembly
Fault status
Status
Wiper activation switch circuit — malfunction detected (B1438)
Repair difficulty: Medium
Diagnostic time: 0.5-1.5 hours
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Code
B1438
FIAT
B — Body
Wiper activation switch circuit
Views:
UK: 4
EN: 7
RU: 4
AI status
Completed
Completed
100%
Causes
- Faulty wiper/washer activation switch
- Damaged or corroded connector(s) at switch or BCM
- Broken or shorted wiring between switch and BCM
- Blown fuse or faulty wiper relay (if applicable)
- Faulty body control module (rare)
Symptoms
- Wipers do not operate or operate intermittently
- Cannot select wiper speeds or intermittent function fails
- Wipers stuck in one position or park function fails
- Erratic wiper behavior (unexpected start/stop)
- Possible related dash message or lamp (BCM fault indicator)
What to check
- Read and record freeze-frame and live data using a diagnostic scanner (wiper switch positions/inputs).
- Visually inspect switch, connectors and wiring harness for damage, corrosion, water ingress or pin deformation.
- Check related fuses and relays for continuity/power.
- Perform continuity and resistance checks on switch circuits (switch to BCM) with connector disconnected.
- Backprobe switch connector with ignition on and operate switch to confirm expected signals/voltages.
- Wiggle test harness while observing live data for intermittent faults.
Signal parameters
- Battery voltage present at switch supply with ignition ON: approx. 11–14 V
- Switch closed continuity: near 0 Ω between relevant pins when engaged; open/infinite when released
- Switch outputs to BCM: expected discrete logic states (ground or battery) or pulsed signals depending on position — verify with oscilloscope or scan tool live data
- Resistance of internal switch contacts may rise when worn: compare to known-good spec where available
- Voltage drop on ground circuits should be minimal (
Diagnostic algorithm
- Connect a diagnostic scanner, read DTCs and live data. Confirm B1438 presence and note any related codes.
- Inspect fuses, relays and visual condition of wiper switch and harness (look for water, corrosion, pin damage).
- With ignition ON, backprobe switch connector and observe voltages while operating each switch position. Compare to expected supply and logic levels.
- Verify continuity between switch signal pins and BCM pins. Check for shorts to ground or battery using multimeter (resistance/voltage tests).
- Perform wiggle test on harness and switch while monitoring live data to find intermittent opens or shorts.
- If wiring and connectors are good, bench-test or substitute a known-good wiper switch to confirm fault follows switch.
- If replacement switch does not clear fault, inspect BCM connector pins and grounds. Check for BCM software updates or intermittent BCM faults.
- After repairs, clear codes and retest all switch positions and wiper functions for correct operation and absence of B1438.
Likely causes
- Intermittent/open circuit in switch harness (pin corrosion, broken wire)
- Short to battery or ground on one of the switch signal wires
- Switch internal contact wear/failure causing unstable signals
- Poor ground at switch or BCM
- Moisture intrusion in switch assembly
Fault status
Status
Wiper activation switch circuit — malfunction detected (B1438)
Repair difficulty: Medium
Diagnostic time: 0.5-1.5 hours
Similar codes
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Code
B1438
HUMMER
B — Body
IPC High Voltage Output Overcurrent to IPM
Views:
UK: 5
EN: 9
RU: 8
AI status
Completed
Completed
100%
Causes
- Faulty wiper/washer activation switch
- Damaged or corroded connector(s) at switch or BCM
- Broken or shorted wiring between switch and BCM
- Blown fuse or faulty wiper relay (if applicable)
- Faulty body control module (rare)
Symptoms
- Wipers do not operate or operate intermittently
- Cannot select wiper speeds or intermittent function fails
- Wipers stuck in one position or park function fails
- Erratic wiper behavior (unexpected start/stop)
- Possible related dash message or lamp (BCM fault indicator)
What to check
- Read and record freeze-frame and live data using a diagnostic scanner (wiper switch positions/inputs).
- Visually inspect switch, connectors and wiring harness for damage, corrosion, water ingress or pin deformation.
- Check related fuses and relays for continuity/power.
- Perform continuity and resistance checks on switch circuits (switch to BCM) with connector disconnected.
- Backprobe switch connector with ignition on and operate switch to confirm expected signals/voltages.
- Wiggle test harness while observing live data for intermittent faults.
Signal parameters
- Battery voltage present at switch supply with ignition ON: approx. 11–14 V
- Switch closed continuity: near 0 Ω between relevant pins when engaged; open/infinite when released
- Switch outputs to BCM: expected discrete logic states (ground or battery) or pulsed signals depending on position — verify with oscilloscope or scan tool live data
- Resistance of internal switch contacts may rise when worn: compare to known-good spec where available
- Voltage drop on ground circuits should be minimal (
Diagnostic algorithm
- Connect a diagnostic scanner, read DTCs and live data. Confirm B1438 presence and note any related codes.
- Inspect fuses, relays and visual condition of wiper switch and harness (look for water, corrosion, pin damage).
- With ignition ON, backprobe switch connector and observe voltages while operating each switch position. Compare to expected supply and logic levels.
- Verify continuity between switch signal pins and BCM pins. Check for shorts to ground or battery using multimeter (resistance/voltage tests).
- Perform wiggle test on harness and switch while monitoring live data to find intermittent opens or shorts.
- If wiring and connectors are good, bench-test or substitute a known-good wiper switch to confirm fault follows switch.
- If replacement switch does not clear fault, inspect BCM connector pins and grounds. Check for BCM software updates or intermittent BCM faults.
- After repairs, clear codes and retest all switch positions and wiper functions for correct operation and absence of B1438.
Likely causes
- Intermittent/open circuit in switch harness (pin corrosion, broken wire)
- Short to battery or ground on one of the switch signal wires
- Switch internal contact wear/failure causing unstable signals
- Poor ground at switch or BCM
- Moisture intrusion in switch assembly
Fault status
Status
Wiper activation switch circuit — malfunction detected (B1438)
Repair difficulty: Medium
Diagnostic time: 0.5-1.5 hours
Similar codes
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Code
B1438
LAND ROVER
B — Body
Wiper mode selection switch - circuit failure
Views:
UK: 4
EN: 6
RU: 4
AI status
Completed
Completed
100%
Causes
- Faulty wiper/washer activation switch
- Damaged or corroded connector(s) at switch or BCM
- Broken or shorted wiring between switch and BCM
- Blown fuse or faulty wiper relay (if applicable)
- Faulty body control module (rare)
Symptoms
- Wipers do not operate or operate intermittently
- Cannot select wiper speeds or intermittent function fails
- Wipers stuck in one position or park function fails
- Erratic wiper behavior (unexpected start/stop)
- Possible related dash message or lamp (BCM fault indicator)
What to check
- Read and record freeze-frame and live data using a diagnostic scanner (wiper switch positions/inputs).
- Visually inspect switch, connectors and wiring harness for damage, corrosion, water ingress or pin deformation.
- Check related fuses and relays for continuity/power.
- Perform continuity and resistance checks on switch circuits (switch to BCM) with connector disconnected.
- Backprobe switch connector with ignition on and operate switch to confirm expected signals/voltages.
- Wiggle test harness while observing live data for intermittent faults.
Signal parameters
- Battery voltage present at switch supply with ignition ON: approx. 11–14 V
- Switch closed continuity: near 0 Ω between relevant pins when engaged; open/infinite when released
- Switch outputs to BCM: expected discrete logic states (ground or battery) or pulsed signals depending on position — verify with oscilloscope or scan tool live data
- Resistance of internal switch contacts may rise when worn: compare to known-good spec where available
- Voltage drop on ground circuits should be minimal (
Diagnostic algorithm
- Connect a diagnostic scanner, read DTCs and live data. Confirm B1438 presence and note any related codes.
- Inspect fuses, relays and visual condition of wiper switch and harness (look for water, corrosion, pin damage).
- With ignition ON, backprobe switch connector and observe voltages while operating each switch position. Compare to expected supply and logic levels.
- Verify continuity between switch signal pins and BCM pins. Check for shorts to ground or battery using multimeter (resistance/voltage tests).
- Perform wiggle test on harness and switch while monitoring live data to find intermittent opens or shorts.
- If wiring and connectors are good, bench-test or substitute a known-good wiper switch to confirm fault follows switch.
- If replacement switch does not clear fault, inspect BCM connector pins and grounds. Check for BCM software updates or intermittent BCM faults.
- After repairs, clear codes and retest all switch positions and wiper functions for correct operation and absence of B1438.
Likely causes
- Intermittent/open circuit in switch harness (pin corrosion, broken wire)
- Short to battery or ground on one of the switch signal wires
- Switch internal contact wear/failure causing unstable signals
- Poor ground at switch or BCM
- Moisture intrusion in switch assembly
Fault status
Status
Wiper activation switch circuit — malfunction detected (B1438)
Repair difficulty: Medium
Diagnostic time: 0.5-1.5 hours
Similar codes
Workshop Manuals
Repair manuals for LAND ROVER
3
Land Rover Defender 300Tdi — Workshop Manual (1996 model year)
Workshop Manual199,00 UAH
Land Rover Defender Workshop Manual Supplement & Body Repair Manual (1999 & 2002 MY)
Workshop Manual199,00 UAH
Land Rover Range Rover — Electrical Library (LRL 0453ENG, 2002)
Workshop Manual199,00 UAH
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Code
B1438
MITSUBISHI
B — Body
FL side impact sensor faulty COM
Views:
UK: 7
EN: 10
RU: 7
AI status
Completed
Completed
100%
Causes
- Faulty wiper/washer activation switch
- Damaged or corroded connector(s) at switch or BCM
- Broken or shorted wiring between switch and BCM
- Blown fuse or faulty wiper relay (if applicable)
- Faulty body control module (rare)
Symptoms
- Wipers do not operate or operate intermittently
- Cannot select wiper speeds or intermittent function fails
- Wipers stuck in one position or park function fails
- Erratic wiper behavior (unexpected start/stop)
- Possible related dash message or lamp (BCM fault indicator)
What to check
- Read and record freeze-frame and live data using a diagnostic scanner (wiper switch positions/inputs).
- Visually inspect switch, connectors and wiring harness for damage, corrosion, water ingress or pin deformation.
- Check related fuses and relays for continuity/power.
- Perform continuity and resistance checks on switch circuits (switch to BCM) with connector disconnected.
- Backprobe switch connector with ignition on and operate switch to confirm expected signals/voltages.
- Wiggle test harness while observing live data for intermittent faults.
Signal parameters
- Battery voltage present at switch supply with ignition ON: approx. 11–14 V
- Switch closed continuity: near 0 Ω between relevant pins when engaged; open/infinite when released
- Switch outputs to BCM: expected discrete logic states (ground or battery) or pulsed signals depending on position — verify with oscilloscope or scan tool live data
- Resistance of internal switch contacts may rise when worn: compare to known-good spec where available
- Voltage drop on ground circuits should be minimal (
Diagnostic algorithm
- Connect a diagnostic scanner, read DTCs and live data. Confirm B1438 presence and note any related codes.
- Inspect fuses, relays and visual condition of wiper switch and harness (look for water, corrosion, pin damage).
- With ignition ON, backprobe switch connector and observe voltages while operating each switch position. Compare to expected supply and logic levels.
- Verify continuity between switch signal pins and BCM pins. Check for shorts to ground or battery using multimeter (resistance/voltage tests).
- Perform wiggle test on harness and switch while monitoring live data to find intermittent opens or shorts.
- If wiring and connectors are good, bench-test or substitute a known-good wiper switch to confirm fault follows switch.
- If replacement switch does not clear fault, inspect BCM connector pins and grounds. Check for BCM software updates or intermittent BCM faults.
- After repairs, clear codes and retest all switch positions and wiper functions for correct operation and absence of B1438.
Likely causes
- Intermittent/open circuit in switch harness (pin corrosion, broken wire)
- Short to battery or ground on one of the switch signal wires
- Switch internal contact wear/failure causing unstable signals
- Poor ground at switch or BCM
- Moisture intrusion in switch assembly
Fault status
Status
Wiper activation switch circuit — malfunction detected (B1438)
Repair difficulty: Medium
Diagnostic time: 0.5-1.5 hours
Similar codes
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+100 karma for a short comment :)
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Code
B1438
Other
B — Body
Wiper Mode Select Switch Circuit Failure
Views:
UK: 23
EN: 30
RU: 22
AI status
Completed
Completed
100%
Causes
- Faulty wiper/washer activation switch
- Damaged or corroded connector(s) at switch or BCM
- Broken or shorted wiring between switch and BCM
- Blown fuse or faulty wiper relay (if applicable)
- Faulty body control module (rare)
Symptoms
- Wipers do not operate or operate intermittently
- Cannot select wiper speeds or intermittent function fails
- Wipers stuck in one position or park function fails
- Erratic wiper behavior (unexpected start/stop)
- Possible related dash message or lamp (BCM fault indicator)
What to check
- Read and record freeze-frame and live data using a diagnostic scanner (wiper switch positions/inputs).
- Visually inspect switch, connectors and wiring harness for damage, corrosion, water ingress or pin deformation.
- Check related fuses and relays for continuity/power.
- Perform continuity and resistance checks on switch circuits (switch to BCM) with connector disconnected.
- Backprobe switch connector with ignition on and operate switch to confirm expected signals/voltages.
- Wiggle test harness while observing live data for intermittent faults.
Signal parameters
- Battery voltage present at switch supply with ignition ON: approx. 11–14 V
- Switch closed continuity: near 0 Ω between relevant pins when engaged; open/infinite when released
- Switch outputs to BCM: expected discrete logic states (ground or battery) or pulsed signals depending on position — verify with oscilloscope or scan tool live data
- Resistance of internal switch contacts may rise when worn: compare to known-good spec where available
- Voltage drop on ground circuits should be minimal (
Diagnostic algorithm
- Connect a diagnostic scanner, read DTCs and live data. Confirm B1438 presence and note any related codes.
- Inspect fuses, relays and visual condition of wiper switch and harness (look for water, corrosion, pin damage).
- With ignition ON, backprobe switch connector and observe voltages while operating each switch position. Compare to expected supply and logic levels.
- Verify continuity between switch signal pins and BCM pins. Check for shorts to ground or battery using multimeter (resistance/voltage tests).
- Perform wiggle test on harness and switch while monitoring live data to find intermittent opens or shorts.
- If wiring and connectors are good, bench-test or substitute a known-good wiper switch to confirm fault follows switch.
- If replacement switch does not clear fault, inspect BCM connector pins and grounds. Check for BCM software updates or intermittent BCM faults.
- After repairs, clear codes and retest all switch positions and wiper functions for correct operation and absence of B1438.
Likely causes
- Intermittent/open circuit in switch harness (pin corrosion, broken wire)
- Short to battery or ground on one of the switch signal wires
- Switch internal contact wear/failure causing unstable signals
- Poor ground at switch or BCM
- Moisture intrusion in switch assembly
Fault status
Status
Wiper activation switch circuit — malfunction detected (B1438)
Repair difficulty: Medium
Diagnostic time: 0.5-1.5 hours
Similar codes
Workshop Manuals
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Land Rover Defender 300Tdi — Workshop Manual (1996 model year)
Workshop Manual199,00 UAH
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Workshop Manual199,00 UAH
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