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Mitsubishi B1558

B1556 and B1558. B1BBC is one of the possible DTCs that could set in the OCM. It sets when a negative weight is being detected on the passenger seat sensors for 10 minutes or more

DriveNot yet established by verified evidence.
ChargeNot yet established by verified evidence.
ServiceNot yet established by verified evidence. Because B1558 is stored in the SRS ECU and may be associated with OCM fault B1BBC, professional diagnosis may be appropriate.
Confidence95%

Quick answer

For applicable 2012–2020 Mitsubishi Outlander and i‑MiEV vehicles in the US, B1558 can be set in the SRS ECU when the occupant classification module (OCM) detects certain seat-related faults. NHTSA communication TT253 specifically states that OCM DTC B1BBC can cause B1558 when negative weight is detected by the passenger-seat sensors for 10 minutes or more.

This page separates verified manufacturer/regulator evidence from supporting material. Unsupported causes, repairs or safety conclusions are not guessed.

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Cracking Mitsubishi Code B1558Car_Fix_DTC
DTC Mitsubishi B1558 Short ExplanationMaxidot Fiat

Videos are supporting material and never override OEM or regulator evidence.

1. What does B1558 mean?

For applicable 2012–2020 Mitsubishi Outlander and i‑MiEV vehicles in the US, B1558 can be set in the SRS ECU when the occupant classification module (OCM) detects certain seat-related faults. NHTSA communication TT253 specifically states that OCM DTC B1BBC can cause B1558 when negative weight is detected by the passenger-seat sensors for 10 minutes or more.

2. Technical explanation

NHTSA manufacturer communication TT253 says that each driver-seat DTC set in the OCM sets two additional generic DTCs in the SRS ECU: B1556 and B1558. It also identifies B1BBC as a possible OCM DTC. B1BBC sets when the passenger-seat sensors detect negative weight for 10 minutes or longer, and B1BBC causes B1558 to set in the SRS ECU.

3. What system is affected?

Supplemental Restraint System (SRS) ECU and occupant classification module (OCM), including passenger-seat sensors.

4. How serious is this code?

Not yet established by verified evidence.

5. Symptoms you may notice

  • B1558 stored in the SRS ECU.
  • An OCM DTC, including possible B1BBC, may be present.

6. Possible causes

  • Negative weight detected on the passenger-seat sensors for 10 minutes or more.
  • A large object under the front passenger seat pushing the seat upward.
  • A reclined front passenger seat back interfering with the rear seat cushion.
  • The supplied evidence is truncated after listing a third reclined-seat situation; its complete description is not established by the supplied evidence.

7. Can I still drive the vehicle?

Not yet established by verified evidence.

8. Can I charge the vehicle?

Not yet established by verified evidence.

9. What you can safely do

  • Inspect for a large object beneath the front passenger seat that may be pushing the seat upward.
  • Check whether the reclined front passenger seat back interferes with the rear seat cushion.
  • Do not perform high-voltage or SRS component repairs based on this information.

10. Step-by-step troubleshooting

  1. Retrieve OCM and SRS ECU diagnostic trouble codes using appropriate diagnostic equipment.
  2. If B1BBC is present, assess whether the passenger-seat sensors have been detecting negative weight for 10 minutes or more.
  3. Check the documented seat-position and under-seat interference situations identified in TT253.
  4. Not yet established by verified evidence: a complete diagnostic workflow, reset procedure, or post-repair verification procedure.

11. When to contact service

Not yet established by verified evidence. Because B1558 is stored in the SRS ECU and may be associated with OCM fault B1BBC, professional diagnosis may be appropriate.

12. What the service center may check

  • Check for objects under the front passenger seat that push the seat upward.
  • Check for interference between a reclined front passenger seat back and the rear seat cushion.
  • Read DTCs from both the OCM and SRS ECU.

13. Possible repair or resolution

  • Remove or correct documented physical interference affecting the passenger seat, if found.
  • Not yet established by verified evidence: a specified repair, parts replacement, calibration requirement, or code-clearing procedure.

14. Affected vehicles

15. Related TSBs / service bulletins

  • NHTSA Manufacturer Communication PDF 10169006, Mitsubishi TT253, published November 26, 2019. It describes B1556/B1558 as generic SRS ECU DTCs associated with OCM DTCs and identifies B1BBC negative-weight detection as a possible trigger for B1558.

16. Recall information

  • Not yet established by verified evidence.

17. Official manufacturer information

Official source: NHTSA Manufacturer Communication PDF 10169006 (Mitsubishi TT253): https://static.nhtsa.gov/odi/tsbs/2019/MC-10169006-9999.pdf

19. Frequently asked questions

What does B1558 mean on an applicable Mitsubishi?

TT253 states that B1558 is an additional generic DTC that can set in the SRS ECU in association with OCM DTCs. B1BBC is specifically identified as a possible OCM DTC that causes B1558.

What can cause B1BBC and B1558?

The verified communication states that B1BBC sets when negative weight is detected on passenger-seat sensors for 10 minutes or more. Listed examples include an object under the front passenger seat pushing it upward and a reclined passenger-seat back interfering with the rear seat cushion.

Which vehicles are covered by the supplied applicability data?

US-market 2012–2020 Mitsubishi Outlander and 2012–2020 Mitsubishi i‑MiEV.

Is it safe to drive or charge with B1558?

Not yet established by verified evidence.

20. Sources & verification

Verified
Mitsubishi B1558: B1556 and B1558. B1BBC is one of the possible DTCs… | EV Diagnostics