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Home / DTC / C1256 — EBCM Internal Malfunction

C1256 — EBCM Internal Malfunction

Detailed page for trouble code C1256.

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Code

C1256

HUMMER C — Chassis

EBCM Internal Malfunction

Brand: HUMMER
Type: C — Chassis
Views: UK: 23 EN: 38 RU: 22
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Faulty EBCM (internal hardware or firmware failure)
  • Low or intermittent battery voltage / poor charging system
  • Corroded, loose or damaged power/ground connectors at the EBCM
  • CAN bus communication faults or wiring damage
  • Faulty wheel speed sensor(s) or damaged sensor wiring
  • Blown fuse or failed relay supplying the EBCM

Symptoms

  • ABS, Traction Control (TCS) and/or StabiliTrak/ESC warning lights illuminated
  • Brake system warning light illuminated; possible degraded braking features
  • Loss of ABS and traction control functionality
  • Diagnostic trouble codes stored in EBCM and possibly other modules
  • Pump motor may run continuously or fail to operate during self-test
  • Possible reduced engine/traction performance or limp-home behavior

What to check

  • Read all stored DTCs and freeze frame data with a capable scan tool; record codes from all modules
  • Verify battery voltage at rest and with starter load (should be ~12.4–12.8V resting, >13.5V charging)
  • Inspect EBCM connector(s) for corrosion, bent pins, water intrusion, or damage
  • Check related fuses and relays for continuity and proper operation
  • Confirm proper ground(s) at the EBCM (measure resistance to chassis ground)
  • Check CAN bus integrity: measure bus voltage levels and verify termination and communication

Signal parameters

  • Module supply voltage: ~11–14.5 V with engine running
  • Module ground continuity:
  • CAN high/low idle voltages: approximately CAN High ~2.5–3.5 V, CAN Low ~1.5–1.0 V (verify against vehicle-specific values)
  • Wheel speed sensor AC output (passive sensors): amplitude and frequency proportional to wheel speed (typical few hundred mV up to several volts depending on speed)
  • Hall/active sensor reference: 5 V reference and digital square wave outputs where applicable
  • Pump motor current draw: within manufacturer spec during operation (excessive or no draw indicates motor/driver problem)

Diagnostic algorithm

  1. Connect a manufacturer-capable scan tool. Read and record all stored codes and freeze frame data from the EBCM and other modules. Note any U-codes indicating communication loss.
  2. Attempt to clear codes and perform a key/engine cycle to see if C1256 returns. Intermittent faults may reappear and help narrow cause.
  3. Verify battery state-of-charge and charging system operation. Recharge or replace weak battery before further testing.
  4. Visually inspect the EBCM housing and connectors for water, corrosion, contamination or physical damage. Repair or replace damaged wiring or connectors.
  5. Check fuses and relays that supply the EBCM and ABS pump. Replace any blown fuses and test relays.
  6. With connector(s) disconnected, back-probe the EBCM power and ground pins. Verify stable 12V supply and good ground continuity to chassis. Repair wiring or grounds that exceed expected resistance.
  7. Check CAN bus lines at the EBCM for correct idle voltages and ability to communicate. If no CAN traffic or abnormal levels are present, trace/repair bus wiring and terminations.
  8. Test wheel speed sensors: measure resistance for open/short, and measure AC output while spinning each wheel (or use scan tool to view wheel speed readings while driving slowly). Repair faulty sensors/wiring.
  9. If available, run EBCM self-tests and active tests with the scan tool to exercise pump motor and valves. Observe motor current draw and module responses.
  10. If wiring, power/grounds, sensors and CAN network are confirmed good and the fault persists, consider module internal failure. Check for available technical service bulletins or software updates before replacement.
  11. If replacement EBCM is required, follow manufacturer procedure for module programming and configuration. After repair, clear codes and perform road test to confirm proper operation.
  12. Re-scan all modules to ensure no related codes remain and that communications are restored.

Likely causes

  • Poor power/ground to the EBCM (loose connector, corrosion, weak battery)
  • CAN bus communication loss or intermittent wiring fault
  • Internal EBCM hardware or firmware failure
  • Faulty wheel speed sensor causing invalid inputs to the EBCM

Fault status

⚠️ Status
EBCM internal malfunction — Electronic Brake Control Module has detected an internal fault or invalid internal conditions. ABS/Traction functionality may be disabled until repaired.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 2-4 hours

Similar codes

C1250 C1251 C1255 C1258 C1246 U0121
Repair manuals

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138

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Code

C1256

HYUNDAI C — Chassis

Rear Right(RR) Height Sensor Abnormal | EMS Indicates CAN Engine Torque Intervention Fault

Brand: HYUNDAI
Type: C — Chassis
Views: UK: 26 EN: 38 RU: 21
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Faulty EBCM (internal hardware or firmware failure)
  • Low or intermittent battery voltage / poor charging system
  • Corroded, loose or damaged power/ground connectors at the EBCM
  • CAN bus communication faults or wiring damage
  • Faulty wheel speed sensor(s) or damaged sensor wiring
  • Blown fuse or failed relay supplying the EBCM

Symptoms

  • ABS, Traction Control (TCS) and/or StabiliTrak/ESC warning lights illuminated
  • Brake system warning light illuminated; possible degraded braking features
  • Loss of ABS and traction control functionality
  • Diagnostic trouble codes stored in EBCM and possibly other modules
  • Pump motor may run continuously or fail to operate during self-test
  • Possible reduced engine/traction performance or limp-home behavior

What to check

  • Read all stored DTCs and freeze frame data with a capable scan tool; record codes from all modules
  • Verify battery voltage at rest and with starter load (should be ~12.4–12.8V resting, >13.5V charging)
  • Inspect EBCM connector(s) for corrosion, bent pins, water intrusion, or damage
  • Check related fuses and relays for continuity and proper operation
  • Confirm proper ground(s) at the EBCM (measure resistance to chassis ground)
  • Check CAN bus integrity: measure bus voltage levels and verify termination and communication

Signal parameters

  • Module supply voltage: ~11–14.5 V with engine running
  • Module ground continuity:
  • CAN high/low idle voltages: approximately CAN High ~2.5–3.5 V, CAN Low ~1.5–1.0 V (verify against vehicle-specific values)
  • Wheel speed sensor AC output (passive sensors): amplitude and frequency proportional to wheel speed (typical few hundred mV up to several volts depending on speed)
  • Hall/active sensor reference: 5 V reference and digital square wave outputs where applicable
  • Pump motor current draw: within manufacturer spec during operation (excessive or no draw indicates motor/driver problem)

Diagnostic algorithm

  1. Connect a manufacturer-capable scan tool. Read and record all stored codes and freeze frame data from the EBCM and other modules. Note any U-codes indicating communication loss.
  2. Attempt to clear codes and perform a key/engine cycle to see if C1256 returns. Intermittent faults may reappear and help narrow cause.
  3. Verify battery state-of-charge and charging system operation. Recharge or replace weak battery before further testing.
  4. Visually inspect the EBCM housing and connectors for water, corrosion, contamination or physical damage. Repair or replace damaged wiring or connectors.
  5. Check fuses and relays that supply the EBCM and ABS pump. Replace any blown fuses and test relays.
  6. With connector(s) disconnected, back-probe the EBCM power and ground pins. Verify stable 12V supply and good ground continuity to chassis. Repair wiring or grounds that exceed expected resistance.
  7. Check CAN bus lines at the EBCM for correct idle voltages and ability to communicate. If no CAN traffic or abnormal levels are present, trace/repair bus wiring and terminations.
  8. Test wheel speed sensors: measure resistance for open/short, and measure AC output while spinning each wheel (or use scan tool to view wheel speed readings while driving slowly). Repair faulty sensors/wiring.
  9. If available, run EBCM self-tests and active tests with the scan tool to exercise pump motor and valves. Observe motor current draw and module responses.
  10. If wiring, power/grounds, sensors and CAN network are confirmed good and the fault persists, consider module internal failure. Check for available technical service bulletins or software updates before replacement.
  11. If replacement EBCM is required, follow manufacturer procedure for module programming and configuration. After repair, clear codes and perform road test to confirm proper operation.
  12. Re-scan all modules to ensure no related codes remain and that communications are restored.

Likely causes

  • Poor power/ground to the EBCM (loose connector, corrosion, weak battery)
  • CAN bus communication loss or intermittent wiring fault
  • Internal EBCM hardware or firmware failure
  • Faulty wheel speed sensor causing invalid inputs to the EBCM

Fault status

⚠️ Status
EBCM internal malfunction — Electronic Brake Control Module has detected an internal fault or invalid internal conditions. ABS/Traction functionality may be disabled until repaired.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 2-4 hours

Similar codes

C1250 C1251 C1255 C1258 C1246 U0121
371

Browse 371 HYUNDAI manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

HYUNDAI

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

C1256

MITSUBISHI C — Chassis

RL inlet valve

Brand: MITSUBISHI
Type: C — Chassis
Views: UK: 20 EN: 39 RU: 20
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Faulty EBCM (internal hardware or firmware failure)
  • Low or intermittent battery voltage / poor charging system
  • Corroded, loose or damaged power/ground connectors at the EBCM
  • CAN bus communication faults or wiring damage
  • Faulty wheel speed sensor(s) or damaged sensor wiring
  • Blown fuse or failed relay supplying the EBCM

Symptoms

  • ABS, Traction Control (TCS) and/or StabiliTrak/ESC warning lights illuminated
  • Brake system warning light illuminated; possible degraded braking features
  • Loss of ABS and traction control functionality
  • Diagnostic trouble codes stored in EBCM and possibly other modules
  • Pump motor may run continuously or fail to operate during self-test
  • Possible reduced engine/traction performance or limp-home behavior

What to check

  • Read all stored DTCs and freeze frame data with a capable scan tool; record codes from all modules
  • Verify battery voltage at rest and with starter load (should be ~12.4–12.8V resting, >13.5V charging)
  • Inspect EBCM connector(s) for corrosion, bent pins, water intrusion, or damage
  • Check related fuses and relays for continuity and proper operation
  • Confirm proper ground(s) at the EBCM (measure resistance to chassis ground)
  • Check CAN bus integrity: measure bus voltage levels and verify termination and communication

Signal parameters

  • Module supply voltage: ~11–14.5 V with engine running
  • Module ground continuity:
  • CAN high/low idle voltages: approximately CAN High ~2.5–3.5 V, CAN Low ~1.5–1.0 V (verify against vehicle-specific values)
  • Wheel speed sensor AC output (passive sensors): amplitude and frequency proportional to wheel speed (typical few hundred mV up to several volts depending on speed)
  • Hall/active sensor reference: 5 V reference and digital square wave outputs where applicable
  • Pump motor current draw: within manufacturer spec during operation (excessive or no draw indicates motor/driver problem)

Diagnostic algorithm

  1. Connect a manufacturer-capable scan tool. Read and record all stored codes and freeze frame data from the EBCM and other modules. Note any U-codes indicating communication loss.
  2. Attempt to clear codes and perform a key/engine cycle to see if C1256 returns. Intermittent faults may reappear and help narrow cause.
  3. Verify battery state-of-charge and charging system operation. Recharge or replace weak battery before further testing.
  4. Visually inspect the EBCM housing and connectors for water, corrosion, contamination or physical damage. Repair or replace damaged wiring or connectors.
  5. Check fuses and relays that supply the EBCM and ABS pump. Replace any blown fuses and test relays.
  6. With connector(s) disconnected, back-probe the EBCM power and ground pins. Verify stable 12V supply and good ground continuity to chassis. Repair wiring or grounds that exceed expected resistance.
  7. Check CAN bus lines at the EBCM for correct idle voltages and ability to communicate. If no CAN traffic or abnormal levels are present, trace/repair bus wiring and terminations.
  8. Test wheel speed sensors: measure resistance for open/short, and measure AC output while spinning each wheel (or use scan tool to view wheel speed readings while driving slowly). Repair faulty sensors/wiring.
  9. If available, run EBCM self-tests and active tests with the scan tool to exercise pump motor and valves. Observe motor current draw and module responses.
  10. If wiring, power/grounds, sensors and CAN network are confirmed good and the fault persists, consider module internal failure. Check for available technical service bulletins or software updates before replacement.
  11. If replacement EBCM is required, follow manufacturer procedure for module programming and configuration. After repair, clear codes and perform road test to confirm proper operation.
  12. Re-scan all modules to ensure no related codes remain and that communications are restored.

Likely causes

  • Poor power/ground to the EBCM (loose connector, corrosion, weak battery)
  • CAN bus communication loss or intermittent wiring fault
  • Internal EBCM hardware or firmware failure
  • Faulty wheel speed sensor causing invalid inputs to the EBCM

Fault status

⚠️ Status
EBCM internal malfunction — Electronic Brake Control Module has detected an internal fault or invalid internal conditions. ABS/Traction functionality may be disabled until repaired.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 2-4 hours

Similar codes

C1250 C1251 C1255 C1258 C1246 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

C1256

Other C — Chassis

ABS Inlet Valve Coil RR Circuit Short To Battery

Brand: Other
Type: C — Chassis
Views: UK: 27 EN: 42 RU: 27
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Faulty EBCM (internal hardware or firmware failure)
  • Low or intermittent battery voltage / poor charging system
  • Corroded, loose or damaged power/ground connectors at the EBCM
  • CAN bus communication faults or wiring damage
  • Faulty wheel speed sensor(s) or damaged sensor wiring
  • Blown fuse or failed relay supplying the EBCM

Symptoms

  • ABS, Traction Control (TCS) and/or StabiliTrak/ESC warning lights illuminated
  • Brake system warning light illuminated; possible degraded braking features
  • Loss of ABS and traction control functionality
  • Diagnostic trouble codes stored in EBCM and possibly other modules
  • Pump motor may run continuously or fail to operate during self-test
  • Possible reduced engine/traction performance or limp-home behavior

What to check

  • Read all stored DTCs and freeze frame data with a capable scan tool; record codes from all modules
  • Verify battery voltage at rest and with starter load (should be ~12.4–12.8V resting, >13.5V charging)
  • Inspect EBCM connector(s) for corrosion, bent pins, water intrusion, or damage
  • Check related fuses and relays for continuity and proper operation
  • Confirm proper ground(s) at the EBCM (measure resistance to chassis ground)
  • Check CAN bus integrity: measure bus voltage levels and verify termination and communication

Signal parameters

  • Module supply voltage: ~11–14.5 V with engine running
  • Module ground continuity:
  • CAN high/low idle voltages: approximately CAN High ~2.5–3.5 V, CAN Low ~1.5–1.0 V (verify against vehicle-specific values)
  • Wheel speed sensor AC output (passive sensors): amplitude and frequency proportional to wheel speed (typical few hundred mV up to several volts depending on speed)
  • Hall/active sensor reference: 5 V reference and digital square wave outputs where applicable
  • Pump motor current draw: within manufacturer spec during operation (excessive or no draw indicates motor/driver problem)

Diagnostic algorithm

  1. Connect a manufacturer-capable scan tool. Read and record all stored codes and freeze frame data from the EBCM and other modules. Note any U-codes indicating communication loss.
  2. Attempt to clear codes and perform a key/engine cycle to see if C1256 returns. Intermittent faults may reappear and help narrow cause.
  3. Verify battery state-of-charge and charging system operation. Recharge or replace weak battery before further testing.
  4. Visually inspect the EBCM housing and connectors for water, corrosion, contamination or physical damage. Repair or replace damaged wiring or connectors.
  5. Check fuses and relays that supply the EBCM and ABS pump. Replace any blown fuses and test relays.
  6. With connector(s) disconnected, back-probe the EBCM power and ground pins. Verify stable 12V supply and good ground continuity to chassis. Repair wiring or grounds that exceed expected resistance.
  7. Check CAN bus lines at the EBCM for correct idle voltages and ability to communicate. If no CAN traffic or abnormal levels are present, trace/repair bus wiring and terminations.
  8. Test wheel speed sensors: measure resistance for open/short, and measure AC output while spinning each wheel (or use scan tool to view wheel speed readings while driving slowly). Repair faulty sensors/wiring.
  9. If available, run EBCM self-tests and active tests with the scan tool to exercise pump motor and valves. Observe motor current draw and module responses.
  10. If wiring, power/grounds, sensors and CAN network are confirmed good and the fault persists, consider module internal failure. Check for available technical service bulletins or software updates before replacement.
  11. If replacement EBCM is required, follow manufacturer procedure for module programming and configuration. After repair, clear codes and perform road test to confirm proper operation.
  12. Re-scan all modules to ensure no related codes remain and that communications are restored.

Likely causes

  • Poor power/ground to the EBCM (loose connector, corrosion, weak battery)
  • CAN bus communication loss or intermittent wiring fault
  • Internal EBCM hardware or firmware failure
  • Faulty wheel speed sensor causing invalid inputs to the EBCM

Fault status

⚠️ Status
EBCM internal malfunction — Electronic Brake Control Module has detected an internal fault or invalid internal conditions. ABS/Traction functionality may be disabled until repaired.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 2-4 hours

Similar codes

C1250 C1251 C1255 C1258 C1246 U0121
6,127

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