Toggle Side Panel

Shopping Cart

No products in the basket.

Shopping Cart

No products in the basket.

Close search
Home / DTC / B1545 — OCSS control unit faulty Comm.

B1545 — OCSS control unit faulty Comm.

Detailed page for trouble code B1545.

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

B1545

MITSUBISHI B — Body

OCSS control unit faulty Comm.

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

Causes

  • Faulty OCSS (occupant classification) control unit
  • Intermittent or permanent open/short in wiring harness between OCSS and network/SRS ECU
  • Poor or corroded connector(s) at OCSS or junction points
  • Low battery voltage, poor ground, or blown fuse supplying the OCSS
  • CAN/LIN vehicle bus fault (missing messages, high bus error counts)
  • Software/firmware mismatch or module configuration error after service

Symptoms

  • SRS/Airbag warning lamp illuminated on dash
  • Occupant detection/seatbelt reminder may behave incorrectly (seat recognized as empty or occupied)
  • Possible deactivation of passenger airbag or inaccurate passenger airbag status indicator
  • Diagnostic trouble code B1545 stored in memory
  • Possible inability for scan tool to communicate with OCSS node

What to check

  • Read and record all stored codes from airbag/SRS and body modules with a factory-quality scan tool
  • Check vehicle battery voltage (engine off and cranking) and charging system health
  • Visually inspect OCSS connector(s) and wiring for corrosion, damage, pin push-out or water ingress
  • Verify fuses and fusible links for circuits powering the OCSS and SRS control units
  • Check for service bulletins or recent work that may have disturbed seat/under-seat wiring
  • Use scan tool to view live data: occupancy messages, module presence, and error counters

Signal parameters

  • Power supply: +12 V nominal at OCSS pin(s) with ignition ON
  • Ground continuity: low ohm to chassis ground
  • CAN bus idle voltages: CAN-H ≈ 2.5 V, CAN-L ≈ 2.5 V (differential ~0 V recessive); dominant transitions present during network activity
  • OCSS network messages: periodic occupancy/alive frames (message ID depends on vehicle); expected update rate and alive counter
  • Faults: increased CAN error counts, missing periodic occupancy message, checksum/alive counter failures

Diagnostic algorithm

  1. Safety first: follow SRS safety procedures. Disable battery negative terminal and wait the manufacturer-recommended time before working near seats or modules.
  2. Connect a proper scan tool. Read and save codes and freeze-frame. Attempt to clear codes and observe if B1545 returns.
  3. Confirm battery voltage is healthy (>12.0 V) and check fuses for OCSS and SRS circuits.
  4. Visually inspect the OCSS connector(s) (typically under or inside the passenger seat) for bent pins, corrosion, water intrusion, or damage. Wiggle-test connectors while watching live data; note any intermittent communication.
  5. Verify power and ground at the OCSS connector with ignition ON. If power or ground missing, trace and repair circuit (check harness, connectors, fusible links).
  6. Check CAN bus integrity: measure CAN‑H and CAN‑L voltages, look for short to 12 V or ground, and confirm expected differential activity with a scope or CAN bus tester. If bus fault present, isolate by disconnecting nodes one at a time to find the fault.
  7. If wiring and bus are good but module does not respond or messages are invalid (bad checksum/expired alive), attempt module reset/reflash per manufacturer procedure if available.
  8. If diagnostics point to internal OCSS failure (confirmed no power/ground/bus issues), replace OCSS module and program/configure per factory procedures.
  9. After repair, clear codes, perform required initialization/calibration for occupant classification and SRS systems, then verify disappearance of B1545 and correct system operation.

Likely causes

  • Corroded/damaged connector or wiring to OCSS
  • Power/ground supply problem at the OCSS module
  • Loss of CAN communications (short, open or high error rate)

Fault status

⚠️ Status
OCSS control unit communication malfunction detected (communication fault stored).
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.0 - 2.5 hours

Similar codes

B1540 B1541 U0073 U0100 U0131
406

Browse 406 MITSUBISHI manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

MITSUBISHI

Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

B1545

Other B — Body

Seat Direction Switch Assembly Circuit Short To Battery

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

Causes

  • Faulty OCSS (occupant classification) control unit
  • Intermittent or permanent open/short in wiring harness between OCSS and network/SRS ECU
  • Poor or corroded connector(s) at OCSS or junction points
  • Low battery voltage, poor ground, or blown fuse supplying the OCSS
  • CAN/LIN vehicle bus fault (missing messages, high bus error counts)
  • Software/firmware mismatch or module configuration error after service

Symptoms

  • SRS/Airbag warning lamp illuminated on dash
  • Occupant detection/seatbelt reminder may behave incorrectly (seat recognized as empty or occupied)
  • Possible deactivation of passenger airbag or inaccurate passenger airbag status indicator
  • Diagnostic trouble code B1545 stored in memory
  • Possible inability for scan tool to communicate with OCSS node

What to check

  • Read and record all stored codes from airbag/SRS and body modules with a factory-quality scan tool
  • Check vehicle battery voltage (engine off and cranking) and charging system health
  • Visually inspect OCSS connector(s) and wiring for corrosion, damage, pin push-out or water ingress
  • Verify fuses and fusible links for circuits powering the OCSS and SRS control units
  • Check for service bulletins or recent work that may have disturbed seat/under-seat wiring
  • Use scan tool to view live data: occupancy messages, module presence, and error counters

Signal parameters

  • Power supply: +12 V nominal at OCSS pin(s) with ignition ON
  • Ground continuity: low ohm to chassis ground
  • CAN bus idle voltages: CAN-H ≈ 2.5 V, CAN-L ≈ 2.5 V (differential ~0 V recessive); dominant transitions present during network activity
  • OCSS network messages: periodic occupancy/alive frames (message ID depends on vehicle); expected update rate and alive counter
  • Faults: increased CAN error counts, missing periodic occupancy message, checksum/alive counter failures

Diagnostic algorithm

  1. Safety first: follow SRS safety procedures. Disable battery negative terminal and wait the manufacturer-recommended time before working near seats or modules.
  2. Connect a proper scan tool. Read and save codes and freeze-frame. Attempt to clear codes and observe if B1545 returns.
  3. Confirm battery voltage is healthy (>12.0 V) and check fuses for OCSS and SRS circuits.
  4. Visually inspect the OCSS connector(s) (typically under or inside the passenger seat) for bent pins, corrosion, water intrusion, or damage. Wiggle-test connectors while watching live data; note any intermittent communication.
  5. Verify power and ground at the OCSS connector with ignition ON. If power or ground missing, trace and repair circuit (check harness, connectors, fusible links).
  6. Check CAN bus integrity: measure CAN‑H and CAN‑L voltages, look for short to 12 V or ground, and confirm expected differential activity with a scope or CAN bus tester. If bus fault present, isolate by disconnecting nodes one at a time to find the fault.
  7. If wiring and bus are good but module does not respond or messages are invalid (bad checksum/expired alive), attempt module reset/reflash per manufacturer procedure if available.
  8. If diagnostics point to internal OCSS failure (confirmed no power/ground/bus issues), replace OCSS module and program/configure per factory procedures.
  9. After repair, clear codes, perform required initialization/calibration for occupant classification and SRS systems, then verify disappearance of B1545 and correct system operation.

Likely causes

  • Corroded/damaged connector or wiring to OCSS
  • Power/ground supply problem at the OCSS module
  • Loss of CAN communications (short, open or high error rate)

Fault status

⚠️ Status
OCSS control unit communication malfunction detected (communication fault stored).
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 1.0 - 2.5 hours

Similar codes

B1540 B1541 U0073 U0100 U0131
8,376

The library contains 8,376 repair and diagnostic manuals. Choose a brand to open the full manual tree by year, model and trim.

ALFA ROMEO
89
AUDI
1,160
BMW
479
CHEVROLET
456
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
2,042
TRIUMPH
131
VOLKSWAGEN
377
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 .