Code
B1501
ALFA ROMEO
B — Body
Left turn indicator warning lamp short to positive
Views:
UK: 6
EN: 8
RU: 13
AI status
Completed
Completed
100%
Causes
- Wiring short to battery positive on the left turn indicator lamp circuit
- Corroded/damaged lamp socket or connector bridging to +12V
- Faulty turn signal switch or multifunction stalk
- Instrument cluster or BCM internal fault (lamp driver shorted)
- Aftermarket accessory or repair that bridged the circuit
- Incorrect bulb type or bulb contact causing unintended positive feed
Symptoms
- Left turn indicator warning lamp illuminated continuously on dash
- Left turn lamps may not flash correctly or may be stuck on
- Possible blown fuse or repeated fuse failures for lighting circuit
- Possible battery drain if short is permanent
- Related multifunction switch functions intermittent or non-functional
What to check
- Read and record freeze-frame/live data and confirm B1501 is stored and current
- Visually inspect left turn lamp(s), sockets, outer lenses and wiring for damage or corrosion
- Check relevant fuses and fuse box for signs of overheating or corrosion
- Measure voltage at the left turn lamp connector with ignition OFF and ON (expect ~0V with OFF and ~pulsed 12V when signalling)
- Unplug left lamp connector and check for +12V presence to determine if circuit is backfeeding
- Inspect and wiggle-test connectors, harness routing, and multifunction switch while monitoring the circuit
Signal parameters
- Ignition OFF: lamp circuit should read ~0 V (no battery positive present)
- Ignition ON, turn signal OFF: lamp circuit should read ~0 V (no continuous feed)
- When left turn is activated: pulsed ~12 V (duty cycle depends on flasher/BCM, typically ~50% at ~1–2 Hz)
- Short to positive condition: steady ~12 V present on circuit when it should be 0 V
- Resistance to ground for lamp circuit with connector disconnected should be high (open circuit except lamp load)
Diagnostic algorithm
- Confirm the code with a diagnostic scanner and note any related codes (left/right indicator, BCM, cluster).
- Reproduce the symptom: observe dash indicator and external lamps while scanning live data.
- Visually inspect left-side lamps, sockets, connectors, and nearby wiring for chafing, corrosion or water ingress.
- With ignition OFF, disconnect the left turn lamp connector. Measure voltage between the lamp + terminal and ground. If ~12 V is present with connector disconnected, the short is upstream (toward BCM/switch).
- If no voltage with lamp disconnected, reconnect lamp and unplug the BCM/cluster connector for the circuit (if accessible). Check for voltage at BCM output pin to determine if the module is driving or the short is external.
- Check continuity between the lamp positive pin and battery positive to locate any unintended direct connection. Use a multimeter or low-current test light; if needed, measure current draw in the circuit to detect a short.
- Inspect and test the multifunction switch: backprobe switch outputs while operating switch; replace or bench-test if it sends continuous +12 V incorrectly.
- If wiring and switch check good, suspect BCM/instrument cluster driver fault. Confirm by substituting known-good module (where possible) or bench-testing module outputs per service manual.
- Repair damaged wiring or connectors (replace harness sections, repair sockets), replace faulty switch or module as required. Clear codes and retest for absence of fault and correct operation.
- After repair, monitor for intermittent faults and verify no additional related codes appear.
Likely causes
- Damaged insulation where the left front/rear lamp harness rubs against bodywork, contacting a constant +12V source
- Corroded lamp socket terminals creating a path to a fused +12V feed
- Faulty turn signal switch sending continuous +12V to the lamp circuit
- Failed lamp driver transistor inside the BCM/instrument cluster shorted to B+
- Recent aftermarket lighting (LED conversions) installed without proper resistors/adapters
Fault status
Status
Left turn indicator warning lamp - short to positive
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
Similar codes
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email
Code
B1501
FIAT
B — Body
Left turn indicator warning lamp short to positive
Views:
UK: 6
EN: 6
RU: 11
AI status
Completed
Completed
100%
Causes
- Wiring short to battery positive on the left turn indicator lamp circuit
- Corroded/damaged lamp socket or connector bridging to +12V
- Faulty turn signal switch or multifunction stalk
- Instrument cluster or BCM internal fault (lamp driver shorted)
- Aftermarket accessory or repair that bridged the circuit
- Incorrect bulb type or bulb contact causing unintended positive feed
Symptoms
- Left turn indicator warning lamp illuminated continuously on dash
- Left turn lamps may not flash correctly or may be stuck on
- Possible blown fuse or repeated fuse failures for lighting circuit
- Possible battery drain if short is permanent
- Related multifunction switch functions intermittent or non-functional
What to check
- Read and record freeze-frame/live data and confirm B1501 is stored and current
- Visually inspect left turn lamp(s), sockets, outer lenses and wiring for damage or corrosion
- Check relevant fuses and fuse box for signs of overheating or corrosion
- Measure voltage at the left turn lamp connector with ignition OFF and ON (expect ~0V with OFF and ~pulsed 12V when signalling)
- Unplug left lamp connector and check for +12V presence to determine if circuit is backfeeding
- Inspect and wiggle-test connectors, harness routing, and multifunction switch while monitoring the circuit
Signal parameters
- Ignition OFF: lamp circuit should read ~0 V (no battery positive present)
- Ignition ON, turn signal OFF: lamp circuit should read ~0 V (no continuous feed)
- When left turn is activated: pulsed ~12 V (duty cycle depends on flasher/BCM, typically ~50% at ~1–2 Hz)
- Short to positive condition: steady ~12 V present on circuit when it should be 0 V
- Resistance to ground for lamp circuit with connector disconnected should be high (open circuit except lamp load)
Diagnostic algorithm
- Confirm the code with a diagnostic scanner and note any related codes (left/right indicator, BCM, cluster).
- Reproduce the symptom: observe dash indicator and external lamps while scanning live data.
- Visually inspect left-side lamps, sockets, connectors, and nearby wiring for chafing, corrosion or water ingress.
- With ignition OFF, disconnect the left turn lamp connector. Measure voltage between the lamp + terminal and ground. If ~12 V is present with connector disconnected, the short is upstream (toward BCM/switch).
- If no voltage with lamp disconnected, reconnect lamp and unplug the BCM/cluster connector for the circuit (if accessible). Check for voltage at BCM output pin to determine if the module is driving or the short is external.
- Check continuity between the lamp positive pin and battery positive to locate any unintended direct connection. Use a multimeter or low-current test light; if needed, measure current draw in the circuit to detect a short.
- Inspect and test the multifunction switch: backprobe switch outputs while operating switch; replace or bench-test if it sends continuous +12 V incorrectly.
- If wiring and switch check good, suspect BCM/instrument cluster driver fault. Confirm by substituting known-good module (where possible) or bench-testing module outputs per service manual.
- Repair damaged wiring or connectors (replace harness sections, repair sockets), replace faulty switch or module as required. Clear codes and retest for absence of fault and correct operation.
- After repair, monitor for intermittent faults and verify no additional related codes appear.
Likely causes
- Damaged insulation where the left front/rear lamp harness rubs against bodywork, contacting a constant +12V source
- Corroded lamp socket terminals creating a path to a fused +12V feed
- Faulty turn signal switch sending continuous +12V to the lamp circuit
- Failed lamp driver transistor inside the BCM/instrument cluster shorted to B+
- Recent aftermarket lighting (LED conversions) installed without proper resistors/adapters
Fault status
Status
Left turn indicator warning lamp - short to positive
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
Similar codes
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email
Code
B1501
MITSUBISHI
B — Body
RR curtain ABG squib open
Views:
UK: 10
EN: 14
RU: 17
AI status
Completed
Completed
100%
Causes
- Wiring short to battery positive on the left turn indicator lamp circuit
- Corroded/damaged lamp socket or connector bridging to +12V
- Faulty turn signal switch or multifunction stalk
- Instrument cluster or BCM internal fault (lamp driver shorted)
- Aftermarket accessory or repair that bridged the circuit
- Incorrect bulb type or bulb contact causing unintended positive feed
Symptoms
- Left turn indicator warning lamp illuminated continuously on dash
- Left turn lamps may not flash correctly or may be stuck on
- Possible blown fuse or repeated fuse failures for lighting circuit
- Possible battery drain if short is permanent
- Related multifunction switch functions intermittent or non-functional
What to check
- Read and record freeze-frame/live data and confirm B1501 is stored and current
- Visually inspect left turn lamp(s), sockets, outer lenses and wiring for damage or corrosion
- Check relevant fuses and fuse box for signs of overheating or corrosion
- Measure voltage at the left turn lamp connector with ignition OFF and ON (expect ~0V with OFF and ~pulsed 12V when signalling)
- Unplug left lamp connector and check for +12V presence to determine if circuit is backfeeding
- Inspect and wiggle-test connectors, harness routing, and multifunction switch while monitoring the circuit
Signal parameters
- Ignition OFF: lamp circuit should read ~0 V (no battery positive present)
- Ignition ON, turn signal OFF: lamp circuit should read ~0 V (no continuous feed)
- When left turn is activated: pulsed ~12 V (duty cycle depends on flasher/BCM, typically ~50% at ~1–2 Hz)
- Short to positive condition: steady ~12 V present on circuit when it should be 0 V
- Resistance to ground for lamp circuit with connector disconnected should be high (open circuit except lamp load)
Diagnostic algorithm
- Confirm the code with a diagnostic scanner and note any related codes (left/right indicator, BCM, cluster).
- Reproduce the symptom: observe dash indicator and external lamps while scanning live data.
- Visually inspect left-side lamps, sockets, connectors, and nearby wiring for chafing, corrosion or water ingress.
- With ignition OFF, disconnect the left turn lamp connector. Measure voltage between the lamp + terminal and ground. If ~12 V is present with connector disconnected, the short is upstream (toward BCM/switch).
- If no voltage with lamp disconnected, reconnect lamp and unplug the BCM/cluster connector for the circuit (if accessible). Check for voltage at BCM output pin to determine if the module is driving or the short is external.
- Check continuity between the lamp positive pin and battery positive to locate any unintended direct connection. Use a multimeter or low-current test light; if needed, measure current draw in the circuit to detect a short.
- Inspect and test the multifunction switch: backprobe switch outputs while operating switch; replace or bench-test if it sends continuous +12 V incorrectly.
- If wiring and switch check good, suspect BCM/instrument cluster driver fault. Confirm by substituting known-good module (where possible) or bench-testing module outputs per service manual.
- Repair damaged wiring or connectors (replace harness sections, repair sockets), replace faulty switch or module as required. Clear codes and retest for absence of fault and correct operation.
- After repair, monitor for intermittent faults and verify no additional related codes appear.
Likely causes
- Damaged insulation where the left front/rear lamp harness rubs against bodywork, contacting a constant +12V source
- Corroded lamp socket terminals creating a path to a fused +12V feed
- Faulty turn signal switch sending continuous +12V to the lamp circuit
- Failed lamp driver transistor inside the BCM/instrument cluster shorted to B+
- Recent aftermarket lighting (LED conversions) installed without proper resistors/adapters
Fault status
Status
Left turn indicator warning lamp - short to positive
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
Similar codes
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email
Code
B1501
Other
B — Body
Lamp Turn Signal Left Circuit Short To Battery
Views:
UK: 19
EN: 24
RU: 34
AI status
Completed
Completed
100%
Causes
- Wiring short to battery positive on the left turn indicator lamp circuit
- Corroded/damaged lamp socket or connector bridging to +12V
- Faulty turn signal switch or multifunction stalk
- Instrument cluster or BCM internal fault (lamp driver shorted)
- Aftermarket accessory or repair that bridged the circuit
- Incorrect bulb type or bulb contact causing unintended positive feed
Symptoms
- Left turn indicator warning lamp illuminated continuously on dash
- Left turn lamps may not flash correctly or may be stuck on
- Possible blown fuse or repeated fuse failures for lighting circuit
- Possible battery drain if short is permanent
- Related multifunction switch functions intermittent or non-functional
What to check
- Read and record freeze-frame/live data and confirm B1501 is stored and current
- Visually inspect left turn lamp(s), sockets, outer lenses and wiring for damage or corrosion
- Check relevant fuses and fuse box for signs of overheating or corrosion
- Measure voltage at the left turn lamp connector with ignition OFF and ON (expect ~0V with OFF and ~pulsed 12V when signalling)
- Unplug left lamp connector and check for +12V presence to determine if circuit is backfeeding
- Inspect and wiggle-test connectors, harness routing, and multifunction switch while monitoring the circuit
Signal parameters
- Ignition OFF: lamp circuit should read ~0 V (no battery positive present)
- Ignition ON, turn signal OFF: lamp circuit should read ~0 V (no continuous feed)
- When left turn is activated: pulsed ~12 V (duty cycle depends on flasher/BCM, typically ~50% at ~1–2 Hz)
- Short to positive condition: steady ~12 V present on circuit when it should be 0 V
- Resistance to ground for lamp circuit with connector disconnected should be high (open circuit except lamp load)
Diagnostic algorithm
- Confirm the code with a diagnostic scanner and note any related codes (left/right indicator, BCM, cluster).
- Reproduce the symptom: observe dash indicator and external lamps while scanning live data.
- Visually inspect left-side lamps, sockets, connectors, and nearby wiring for chafing, corrosion or water ingress.
- With ignition OFF, disconnect the left turn lamp connector. Measure voltage between the lamp + terminal and ground. If ~12 V is present with connector disconnected, the short is upstream (toward BCM/switch).
- If no voltage with lamp disconnected, reconnect lamp and unplug the BCM/cluster connector for the circuit (if accessible). Check for voltage at BCM output pin to determine if the module is driving or the short is external.
- Check continuity between the lamp positive pin and battery positive to locate any unintended direct connection. Use a multimeter or low-current test light; if needed, measure current draw in the circuit to detect a short.
- Inspect and test the multifunction switch: backprobe switch outputs while operating switch; replace or bench-test if it sends continuous +12 V incorrectly.
- If wiring and switch check good, suspect BCM/instrument cluster driver fault. Confirm by substituting known-good module (where possible) or bench-testing module outputs per service manual.
- Repair damaged wiring or connectors (replace harness sections, repair sockets), replace faulty switch or module as required. Clear codes and retest for absence of fault and correct operation.
- After repair, monitor for intermittent faults and verify no additional related codes appear.
Likely causes
- Damaged insulation where the left front/rear lamp harness rubs against bodywork, contacting a constant +12V source
- Corroded lamp socket terminals creating a path to a fused +12V feed
- Faulty turn signal switch sending continuous +12V to the lamp circuit
- Failed lamp driver transistor inside the BCM/instrument cluster shorted to B+
- Recent aftermarket lighting (LED conversions) installed without proper resistors/adapters
Fault status
Status
Left turn indicator warning lamp - short to positive
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
Similar codes
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email