Toggle Side Panel

Shopping Cart

No products in the basket.

Shopping Cart

No products in the basket.

Close search
Home / DTC / B1356 — Ignition on circuit

B1356 — Ignition on circuit

Detailed page for trouble code B1356.

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

B1356

ALFA ROMEO B — Body

Ignition on circuit

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

Causes

  • Blown ignition-related fuse
  • Faulty ignition switch
  • Faulty ignition (IG) relay
  • Open, short to ground or short to battery in wiring harness for IGN_ON circuit
  • Poor or corroded connector or terminal at switch, relay or module
  • Faulty body control module / instrument cluster / ECU input stage

Symptoms

  • No-crank or no-start condition on some key positions
  • Dash/instrument cluster not powering up or flickering when key ON
  • Intermittent loss of vehicle electrical functions when key is ON
  • Possible inability to record other control unit faults
  • Battery drain or parasitic draw if ignition circuit stuck ON

What to check

  • Read freeze frame and related codes with a diagnostic scanner; note key position when fault set
  • Check battery voltage (resting and with key ON) and battery terminals for good contact
  • Inspect fuses and relays related to IGN/IGNITION/IG circuits
  • Visual inspection of ignition switch, steering column connectors, fusebox and associated wiring for damage or corrosion
  • Backprobe the IGN_ON feed at the relay/switch and target module while operating the ignition to verify voltage and continuity
  • Wiggle harnesses and connectors while monitoring voltage to detect intermittent faults

Signal parameters

  • Ignition ON feed voltage: approx. battery voltage (nominal 12.0–14.5 V) with key in ON/Run
  • Ignition OFF: feed should be near 0 V (or within the vehicle's defined off threshold)
  • Cranking: voltage may drop but should remain >9–10 V at starter engagement
  • Continuity: low resistance (typically
  • Intermittent faults: voltage may flicker or drop quickly under wiggle test or vibration

Diagnostic algorithm

  1. Connect a scan tool, read all stored codes and freeze-frame data; note the key position and battery voltage when the code was recorded.
  2. Check battery condition and terminals; ensure good supply before proceeding.
  3. Inspect fuses and relay(s) for the ignition feed; swap a known-good identical relay if suspect.
  4. Visually inspect wiring from ignition switch to fusebox/relay and to the affected module(s); look for damage, pinched areas, corrosion, or aftermarket splices.
  5. Backprobe the ignition feed at the relay output and at the receiving module; verify battery voltage is present with key in ON and that it disappears with key off as expected.
  6. Perform a wiggle test on steering column harnesses, switch connectors and fusebox while watching voltage or live data for intermittent changes.
  7. If an open or high resistance is found, isolate by testing continuity between ignition switch output and module connector; repair or replace damaged wiring/connectors.
  8. If the wiring and fuses/relays are good but the feed is absent at the switch, test and replace the ignition switch.
  9. If feed is present to the switch/relay but missing at the control module input, check the module connector; repair wiring or replace the module only after confirming input pin problems.
  10. After repairs, clear codes, verify stable ignition feed under all key positions and perform a road test to confirm the fault does not return.

Likely causes

  • Intermittent connector making/breaking under vibration (common at steering column)
  • Damaged insulation chafing to ground causing intermittent short
  • Failed ignition switch contacts not supplying the IG feed
  • Corroded fusebox terminal or relay socket
  • Aftermarket alarm/immobilizer wiring interfering with ignition feed

Fault status

⚠️ Status
The vehicle control module has detected an abnormal condition on the Ignition ON circuit (missing, low, high, or intermittent voltage). Verify ignition feed, fuses/relays, wiring and related modules before replacing control units.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.0 - 2.5 hours

Similar codes

B1355 B1357 B1320 B1000
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

B1356

FIAT B — Body

Ignition on circuit

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

Causes

  • Blown ignition-related fuse
  • Faulty ignition switch
  • Faulty ignition (IG) relay
  • Open, short to ground or short to battery in wiring harness for IGN_ON circuit
  • Poor or corroded connector or terminal at switch, relay or module
  • Faulty body control module / instrument cluster / ECU input stage

Symptoms

  • No-crank or no-start condition on some key positions
  • Dash/instrument cluster not powering up or flickering when key ON
  • Intermittent loss of vehicle electrical functions when key is ON
  • Possible inability to record other control unit faults
  • Battery drain or parasitic draw if ignition circuit stuck ON

What to check

  • Read freeze frame and related codes with a diagnostic scanner; note key position when fault set
  • Check battery voltage (resting and with key ON) and battery terminals for good contact
  • Inspect fuses and relays related to IGN/IGNITION/IG circuits
  • Visual inspection of ignition switch, steering column connectors, fusebox and associated wiring for damage or corrosion
  • Backprobe the IGN_ON feed at the relay/switch and target module while operating the ignition to verify voltage and continuity
  • Wiggle harnesses and connectors while monitoring voltage to detect intermittent faults

Signal parameters

  • Ignition ON feed voltage: approx. battery voltage (nominal 12.0–14.5 V) with key in ON/Run
  • Ignition OFF: feed should be near 0 V (or within the vehicle's defined off threshold)
  • Cranking: voltage may drop but should remain >9–10 V at starter engagement
  • Continuity: low resistance (typically
  • Intermittent faults: voltage may flicker or drop quickly under wiggle test or vibration

Diagnostic algorithm

  1. Connect a scan tool, read all stored codes and freeze-frame data; note the key position and battery voltage when the code was recorded.
  2. Check battery condition and terminals; ensure good supply before proceeding.
  3. Inspect fuses and relay(s) for the ignition feed; swap a known-good identical relay if suspect.
  4. Visually inspect wiring from ignition switch to fusebox/relay and to the affected module(s); look for damage, pinched areas, corrosion, or aftermarket splices.
  5. Backprobe the ignition feed at the relay output and at the receiving module; verify battery voltage is present with key in ON and that it disappears with key off as expected.
  6. Perform a wiggle test on steering column harnesses, switch connectors and fusebox while watching voltage or live data for intermittent changes.
  7. If an open or high resistance is found, isolate by testing continuity between ignition switch output and module connector; repair or replace damaged wiring/connectors.
  8. If the wiring and fuses/relays are good but the feed is absent at the switch, test and replace the ignition switch.
  9. If feed is present to the switch/relay but missing at the control module input, check the module connector; repair wiring or replace the module only after confirming input pin problems.
  10. After repairs, clear codes, verify stable ignition feed under all key positions and perform a road test to confirm the fault does not return.

Likely causes

  • Intermittent connector making/breaking under vibration (common at steering column)
  • Damaged insulation chafing to ground causing intermittent short
  • Failed ignition switch contacts not supplying the IG feed
  • Corroded fusebox terminal or relay socket
  • Aftermarket alarm/immobilizer wiring interfering with ignition feed

Fault status

⚠️ Status
The vehicle control module has detected an abnormal condition on the Ignition ON circuit (missing, low, high, or intermittent voltage). Verify ignition feed, fuses/relays, wiring and related modules before replacing control units.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.0 - 2.5 hours

Similar codes

B1355 B1357 B1320 B1000
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

B1356

Other B — Body

Ignition Run Circuit Open

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

Causes

  • Blown ignition-related fuse
  • Faulty ignition switch
  • Faulty ignition (IG) relay
  • Open, short to ground or short to battery in wiring harness for IGN_ON circuit
  • Poor or corroded connector or terminal at switch, relay or module
  • Faulty body control module / instrument cluster / ECU input stage

Symptoms

  • No-crank or no-start condition on some key positions
  • Dash/instrument cluster not powering up or flickering when key ON
  • Intermittent loss of vehicle electrical functions when key is ON
  • Possible inability to record other control unit faults
  • Battery drain or parasitic draw if ignition circuit stuck ON

What to check

  • Read freeze frame and related codes with a diagnostic scanner; note key position when fault set
  • Check battery voltage (resting and with key ON) and battery terminals for good contact
  • Inspect fuses and relays related to IGN/IGNITION/IG circuits
  • Visual inspection of ignition switch, steering column connectors, fusebox and associated wiring for damage or corrosion
  • Backprobe the IGN_ON feed at the relay/switch and target module while operating the ignition to verify voltage and continuity
  • Wiggle harnesses and connectors while monitoring voltage to detect intermittent faults

Signal parameters

  • Ignition ON feed voltage: approx. battery voltage (nominal 12.0–14.5 V) with key in ON/Run
  • Ignition OFF: feed should be near 0 V (or within the vehicle's defined off threshold)
  • Cranking: voltage may drop but should remain >9–10 V at starter engagement
  • Continuity: low resistance (typically
  • Intermittent faults: voltage may flicker or drop quickly under wiggle test or vibration

Diagnostic algorithm

  1. Connect a scan tool, read all stored codes and freeze-frame data; note the key position and battery voltage when the code was recorded.
  2. Check battery condition and terminals; ensure good supply before proceeding.
  3. Inspect fuses and relay(s) for the ignition feed; swap a known-good identical relay if suspect.
  4. Visually inspect wiring from ignition switch to fusebox/relay and to the affected module(s); look for damage, pinched areas, corrosion, or aftermarket splices.
  5. Backprobe the ignition feed at the relay output and at the receiving module; verify battery voltage is present with key in ON and that it disappears with key off as expected.
  6. Perform a wiggle test on steering column harnesses, switch connectors and fusebox while watching voltage or live data for intermittent changes.
  7. If an open or high resistance is found, isolate by testing continuity between ignition switch output and module connector; repair or replace damaged wiring/connectors.
  8. If the wiring and fuses/relays are good but the feed is absent at the switch, test and replace the ignition switch.
  9. If feed is present to the switch/relay but missing at the control module input, check the module connector; repair wiring or replace the module only after confirming input pin problems.
  10. After repairs, clear codes, verify stable ignition feed under all key positions and perform a road test to confirm the fault does not return.

Likely causes

  • Intermittent connector making/breaking under vibration (common at steering column)
  • Damaged insulation chafing to ground causing intermittent short
  • Failed ignition switch contacts not supplying the IG feed
  • Corroded fusebox terminal or relay socket
  • Aftermarket alarm/immobilizer wiring interfering with ignition feed

Fault status

⚠️ Status
The vehicle control module has detected an abnormal condition on the Ignition ON circuit (missing, low, high, or intermittent voltage). Verify ignition feed, fuses/relays, wiring and related modules before replacing control units.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.0 - 2.5 hours

Similar codes

B1355 B1357 B1320 B1000
9,130

The library contains 9,130 repair and diagnostic manuals. Choose a brand to open the full manual tree by year, model and trim.

ALFA ROMEO
89
AUDI
1,243
BMW
479
CADILLAC
206
CHEVROLET
456
CHRYSLER
193
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
2,065
TRIUMPH
131
VOLKSWAGEN
626
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 .