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Home / DTC / B1440 — Power Mode Master Input Circuits Mismatch

B1440 — Power Mode Master Input Circuits Mismatch

Detailed page for trouble code B1440.

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22,491specific
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Code

B1440

HUMMER B — Body

Power Mode Master Input Circuits Mismatch

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

Causes

  • Damaged or shorted wiring harness between ignition/power mode switch and vehicle modules
  • Poor or intermittent connector contact (corrosion, bent pins, loose terminals)
  • Faulty ignition switch / power mode selector (mechanical or electrical failure)
  • Faulty body control module (BCM) or instrument cluster reporting power mode
  • Low battery voltage or intermittent battery/ground connection
  • Software/configuration mismatch or module needing reflash

Symptoms

  • Malfunction of key-on/accessory functions (radio, windows, HVAC)
  • No-crank or intermittent crank/no-start related to power mode
  • Illumination of dash warning lamp(s) and stored B1440
  • Unresponsive or inconsistent ignition key positions (ACC/RUN/START)
  • Erratic accessory behavior or modules reverting to default/safe mode

What to check

  • Scan for B1440 and any stored/related codes (U-codes, B-codes, P-codes)
  • Verify battery voltage is healthy (12.4–12.8 V at rest, >13.5 V with engine running)
  • Inspect connectors and wiring at the ignition/power mode switch, BCM, and IPC
  • Backprobe power mode signal circuits and monitor while cycling key positions
  • Check for CAN/LIN errors or modules reporting lost communication
  • Perform wiggle test on harness while monitoring signal and code status

Signal parameters

  • Power mode signal expected states: OFF, ACC, RUN (IGN), START — verify correct state transitions when key operated
  • Voltage on power mode feed: near battery voltage (~12 V) when asserted, ~0 V when not; some inputs are low-side switched or pull-ups — consult wiring diagram
  • Digital/logic inputs may be switched to ground or to ignition voltage; open circuits or intermediate voltages indicate wiring/connector issues
  • CAN/LIN bus messages: modules should publish consistent power mode status; check for missing or conflicting messages

Diagnostic algorithm

  1. Retrieve all DTCs and freeze frame data. Note any communication (U0xxx) or voltage (P0562) codes.
  2. Verify battery condition and charge if needed. Clear codes and attempt to reproduce with a fully charged battery.
  3. Visually inspect connectors and wiring for damage, corrosion, or pin distortion at ignition switch, BCM, and instrument cluster.
  4. Backprobe the power mode input circuits at the switch and at the receiving module(s). With a DVOM or scope, observe signal behavior across OFF/ACC/RUN/START. Look for missing transitions, intermittent, or contradictory states between modules.
  5. If signals are incorrect at the module but correct at the switch, trace and repair wiring/connectors between switch and module. If signals are incorrect at the switch, test/replace the ignition/power mode switch.
  6. Monitor CAN/LIN communications with a scan tool to ensure modules are broadcasting and receiving power mode messages consistently. Repair bus faults (terminations, shorts) if present.
  7. If wiring and switch check good and communication is stable, check for module software updates or configuration errors. Reflash or reprogram BCM/IPC as per manufacturer service information.
  8. Replace the affected module only after confirming a hardware failure; verify repair by clearing codes and performing a full function test across multiple key cycles.

Likely causes

  • Loose or corroded connector at ignition switch or BCM
  • Open or shorted signal wire between ignition switch and BCM/IPC
  • Faulty ignition switch that fails to assert expected voltage in a key position
  • Module communication failure (BCM or cluster) or lost CAN messages

Fault status

⚠️ Status
Power Mode Master input circuits report inconsistent or invalid states between modules; vehicle modules disagree on ignition/power mode.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.0-3.0 hours

Similar codes

B1441 U0100 U0073 U0121 P0562
Repair manuals

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138

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Code

B1440

LAND ROVER B — Body

Windshield wiper mode selection switch - short circuit for battery

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

Causes

  • Damaged or shorted wiring harness between ignition/power mode switch and vehicle modules
  • Poor or intermittent connector contact (corrosion, bent pins, loose terminals)
  • Faulty ignition switch / power mode selector (mechanical or electrical failure)
  • Faulty body control module (BCM) or instrument cluster reporting power mode
  • Low battery voltage or intermittent battery/ground connection
  • Software/configuration mismatch or module needing reflash

Symptoms

  • Malfunction of key-on/accessory functions (radio, windows, HVAC)
  • No-crank or intermittent crank/no-start related to power mode
  • Illumination of dash warning lamp(s) and stored B1440
  • Unresponsive or inconsistent ignition key positions (ACC/RUN/START)
  • Erratic accessory behavior or modules reverting to default/safe mode

What to check

  • Scan for B1440 and any stored/related codes (U-codes, B-codes, P-codes)
  • Verify battery voltage is healthy (12.4–12.8 V at rest, >13.5 V with engine running)
  • Inspect connectors and wiring at the ignition/power mode switch, BCM, and IPC
  • Backprobe power mode signal circuits and monitor while cycling key positions
  • Check for CAN/LIN errors or modules reporting lost communication
  • Perform wiggle test on harness while monitoring signal and code status

Signal parameters

  • Power mode signal expected states: OFF, ACC, RUN (IGN), START — verify correct state transitions when key operated
  • Voltage on power mode feed: near battery voltage (~12 V) when asserted, ~0 V when not; some inputs are low-side switched or pull-ups — consult wiring diagram
  • Digital/logic inputs may be switched to ground or to ignition voltage; open circuits or intermediate voltages indicate wiring/connector issues
  • CAN/LIN bus messages: modules should publish consistent power mode status; check for missing or conflicting messages

Diagnostic algorithm

  1. Retrieve all DTCs and freeze frame data. Note any communication (U0xxx) or voltage (P0562) codes.
  2. Verify battery condition and charge if needed. Clear codes and attempt to reproduce with a fully charged battery.
  3. Visually inspect connectors and wiring for damage, corrosion, or pin distortion at ignition switch, BCM, and instrument cluster.
  4. Backprobe the power mode input circuits at the switch and at the receiving module(s). With a DVOM or scope, observe signal behavior across OFF/ACC/RUN/START. Look for missing transitions, intermittent, or contradictory states between modules.
  5. If signals are incorrect at the module but correct at the switch, trace and repair wiring/connectors between switch and module. If signals are incorrect at the switch, test/replace the ignition/power mode switch.
  6. Monitor CAN/LIN communications with a scan tool to ensure modules are broadcasting and receiving power mode messages consistently. Repair bus faults (terminations, shorts) if present.
  7. If wiring and switch check good and communication is stable, check for module software updates or configuration errors. Reflash or reprogram BCM/IPC as per manufacturer service information.
  8. Replace the affected module only after confirming a hardware failure; verify repair by clearing codes and performing a full function test across multiple key cycles.

Likely causes

  • Loose or corroded connector at ignition switch or BCM
  • Open or shorted signal wire between ignition switch and BCM/IPC
  • Faulty ignition switch that fails to assert expected voltage in a key position
  • Module communication failure (BCM or cluster) or lost CAN messages

Fault status

⚠️ Status
Power Mode Master input circuits report inconsistent or invalid states between modules; vehicle modules disagree on ignition/power mode.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.0-3.0 hours

Similar codes

B1441 U0100 U0073 U0121 P0562
282

Browse 282 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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Code

B1440

MITSUBISHI B — Body

FR curtain ABG squib short

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

Causes

  • Damaged or shorted wiring harness between ignition/power mode switch and vehicle modules
  • Poor or intermittent connector contact (corrosion, bent pins, loose terminals)
  • Faulty ignition switch / power mode selector (mechanical or electrical failure)
  • Faulty body control module (BCM) or instrument cluster reporting power mode
  • Low battery voltage or intermittent battery/ground connection
  • Software/configuration mismatch or module needing reflash

Symptoms

  • Malfunction of key-on/accessory functions (radio, windows, HVAC)
  • No-crank or intermittent crank/no-start related to power mode
  • Illumination of dash warning lamp(s) and stored B1440
  • Unresponsive or inconsistent ignition key positions (ACC/RUN/START)
  • Erratic accessory behavior or modules reverting to default/safe mode

What to check

  • Scan for B1440 and any stored/related codes (U-codes, B-codes, P-codes)
  • Verify battery voltage is healthy (12.4–12.8 V at rest, >13.5 V with engine running)
  • Inspect connectors and wiring at the ignition/power mode switch, BCM, and IPC
  • Backprobe power mode signal circuits and monitor while cycling key positions
  • Check for CAN/LIN errors or modules reporting lost communication
  • Perform wiggle test on harness while monitoring signal and code status

Signal parameters

  • Power mode signal expected states: OFF, ACC, RUN (IGN), START — verify correct state transitions when key operated
  • Voltage on power mode feed: near battery voltage (~12 V) when asserted, ~0 V when not; some inputs are low-side switched or pull-ups — consult wiring diagram
  • Digital/logic inputs may be switched to ground or to ignition voltage; open circuits or intermediate voltages indicate wiring/connector issues
  • CAN/LIN bus messages: modules should publish consistent power mode status; check for missing or conflicting messages

Diagnostic algorithm

  1. Retrieve all DTCs and freeze frame data. Note any communication (U0xxx) or voltage (P0562) codes.
  2. Verify battery condition and charge if needed. Clear codes and attempt to reproduce with a fully charged battery.
  3. Visually inspect connectors and wiring for damage, corrosion, or pin distortion at ignition switch, BCM, and instrument cluster.
  4. Backprobe the power mode input circuits at the switch and at the receiving module(s). With a DVOM or scope, observe signal behavior across OFF/ACC/RUN/START. Look for missing transitions, intermittent, or contradictory states between modules.
  5. If signals are incorrect at the module but correct at the switch, trace and repair wiring/connectors between switch and module. If signals are incorrect at the switch, test/replace the ignition/power mode switch.
  6. Monitor CAN/LIN communications with a scan tool to ensure modules are broadcasting and receiving power mode messages consistently. Repair bus faults (terminations, shorts) if present.
  7. If wiring and switch check good and communication is stable, check for module software updates or configuration errors. Reflash or reprogram BCM/IPC as per manufacturer service information.
  8. Replace the affected module only after confirming a hardware failure; verify repair by clearing codes and performing a full function test across multiple key cycles.

Likely causes

  • Loose or corroded connector at ignition switch or BCM
  • Open or shorted signal wire between ignition switch and BCM/IPC
  • Faulty ignition switch that fails to assert expected voltage in a key position
  • Module communication failure (BCM or cluster) or lost CAN messages

Fault status

⚠️ Status
Power Mode Master input circuits report inconsistent or invalid states between modules; vehicle modules disagree on ignition/power mode.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.0-3.0 hours

Similar codes

B1441 U0100 U0073 U0121 P0562
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.
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Code

B1440

Other B — Body

Wiper Mode Select Switch Circuit Short To Battery

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

Causes

  • Damaged or shorted wiring harness between ignition/power mode switch and vehicle modules
  • Poor or intermittent connector contact (corrosion, bent pins, loose terminals)
  • Faulty ignition switch / power mode selector (mechanical or electrical failure)
  • Faulty body control module (BCM) or instrument cluster reporting power mode
  • Low battery voltage or intermittent battery/ground connection
  • Software/configuration mismatch or module needing reflash

Symptoms

  • Malfunction of key-on/accessory functions (radio, windows, HVAC)
  • No-crank or intermittent crank/no-start related to power mode
  • Illumination of dash warning lamp(s) and stored B1440
  • Unresponsive or inconsistent ignition key positions (ACC/RUN/START)
  • Erratic accessory behavior or modules reverting to default/safe mode

What to check

  • Scan for B1440 and any stored/related codes (U-codes, B-codes, P-codes)
  • Verify battery voltage is healthy (12.4–12.8 V at rest, >13.5 V with engine running)
  • Inspect connectors and wiring at the ignition/power mode switch, BCM, and IPC
  • Backprobe power mode signal circuits and monitor while cycling key positions
  • Check for CAN/LIN errors or modules reporting lost communication
  • Perform wiggle test on harness while monitoring signal and code status

Signal parameters

  • Power mode signal expected states: OFF, ACC, RUN (IGN), START — verify correct state transitions when key operated
  • Voltage on power mode feed: near battery voltage (~12 V) when asserted, ~0 V when not; some inputs are low-side switched or pull-ups — consult wiring diagram
  • Digital/logic inputs may be switched to ground or to ignition voltage; open circuits or intermediate voltages indicate wiring/connector issues
  • CAN/LIN bus messages: modules should publish consistent power mode status; check for missing or conflicting messages

Diagnostic algorithm

  1. Retrieve all DTCs and freeze frame data. Note any communication (U0xxx) or voltage (P0562) codes.
  2. Verify battery condition and charge if needed. Clear codes and attempt to reproduce with a fully charged battery.
  3. Visually inspect connectors and wiring for damage, corrosion, or pin distortion at ignition switch, BCM, and instrument cluster.
  4. Backprobe the power mode input circuits at the switch and at the receiving module(s). With a DVOM or scope, observe signal behavior across OFF/ACC/RUN/START. Look for missing transitions, intermittent, or contradictory states between modules.
  5. If signals are incorrect at the module but correct at the switch, trace and repair wiring/connectors between switch and module. If signals are incorrect at the switch, test/replace the ignition/power mode switch.
  6. Monitor CAN/LIN communications with a scan tool to ensure modules are broadcasting and receiving power mode messages consistently. Repair bus faults (terminations, shorts) if present.
  7. If wiring and switch check good and communication is stable, check for module software updates or configuration errors. Reflash or reprogram BCM/IPC as per manufacturer service information.
  8. Replace the affected module only after confirming a hardware failure; verify repair by clearing codes and performing a full function test across multiple key cycles.

Likely causes

  • Loose or corroded connector at ignition switch or BCM
  • Open or shorted signal wire between ignition switch and BCM/IPC
  • Faulty ignition switch that fails to assert expected voltage in a key position
  • Module communication failure (BCM or cluster) or lost CAN messages

Fault status

⚠️ Status
Power Mode Master input circuits report inconsistent or invalid states between modules; vehicle modules disagree on ignition/power mode.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.0-3.0 hours

Similar codes

B1441 U0100 U0073 U0121 P0562
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