AutoCodesGeneric – B1788

B1788 Code - Rear Occupant Classification Sensor Right Collision Detection

Quick Answer

The Diagnostic Trouble Code (DTC) B1788 is output when the Occupant Detection ECU receives a collision detection signal sent by the Rear Occupant Classification Sensor Right (RH) when an accident occurs. Common causes include Faulty Separate Type Rear Seat Cushion Spring Assembly Right (Rear Occupant Classification Sensor Right), Separate Type Rear Seat Cushion Spring Assembly Right harness is open or shorted, Separate Type Rear Seat Cushion Spring Assembly Right circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means
B1788 indicates Rear Occupant Classification Sensor Right Collision Detection.
Common causes
Common causes include Faulty Separate Type Rear Seat Cushion Spring Assembly Right (Rear Occupant Classification Sensor Right), Separate Type Rear Seat Cushion Spring Assembly Right harness is open or shorted, Separate Type Rear Seat Cushion Spring Assembly Right circuit poor electrical connection.
Severity
High - diagnose this code as soon as possible.
Can I drive?
Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
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Code Popularity 4,982
How popular is this code, among other codes? Low
Table of contents Created and updated by William Orellana on Oct 16, 2022
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Code B1788 Description

The Diagnostic Trouble Code (DTC) B1788 is output when the Occupant Detection ECU receives a collision detection signal sent by the Rear Occupant Classification Sensor Right (RH) when an accident occurs. DTC B1788 is also stored when the separate type of front seat cushion spring assembly is subjected to a strong impact, even if an actual accident has not occurred. However, when the Occupant Detection ECU outputs a collision detection signal, even if the vehicle is not in a collision, DTC B1788 can be cleared by performing the zero point calibration and sensitivity check. Therefore, when DTC B1788 is output, first perform the zero point calibration and sensitivity check.
OBDII Code B1788 - Rear Occupant Classification Sensor Right Collision Detection - AutoCodes.com
B1788 Code - Rear Occupant Classification Sensor Right Collision Detection

What are the Possible Causes of the DTC B1788?

  • Faulty Separate Type Rear Seat Cushion Spring Assembly Right (Rear Occupant Classification Sensor Right)
  • Separate Type Rear Seat Cushion Spring Assembly Right harness is open or shorted
  • Separate Type Rear Seat Cushion Spring Assembly Right circuit poor electrical connection
  • Faulty Occupant Detection ECU

How to Fix the DTC B1788?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B1788 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the B1788 code?

Need more information on how to fix the B1788 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B1788 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

  • B1788 Lexus — Rear Occupant Classification Sensor Right Collision Detection
  • B1788 Scion — Rear Occupant Classification Sensor Right Collision Detection
  • B1788 Toyota — Rear Occupant Classification Sensor Right Collision Detection

Precautions for SRS “AIR BAG” and “SEAT BELT PRE-TENSIONER” Service

  • Never probe the electrical connectors on air bag, side air curtain modules or seat belts.
  • Never disassemble or tamper with safety belt buckle/retractor pretensioners, adaptive load limiting retractors, safety belt inflators, or probe the electrical connectors.
  • Do not use electrical test equipment to check SRS circuits unless instructed to in this Service Manual.
  • Before servicing the SRS, turn ignition switch OFF, disconnect both battery cables and wait at least 3 minutes. For approximately 3 minutes after the cables are removed, it is still possible for the air bag and seat belt pre-tensioner to deploy. Therefore, do not work on any SRS connectors or wires until at least 3 minutes have passed.

Failure to follow this instruction may result in the accidental deployment of these modules, which increases the risk of serious personal injury or death.

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about B1788 Code

1. What does the OBDII code B1788 mean?

The B1788 code indicates a fault in the rear occupant classification sensor on the right side, specifically related to collision detection.

2. What are the common symptoms of the B1788 code?

Symptoms may include the airbag warning light being illuminated, improper airbag deployment functionality, or incorrect detection of rear seat occupants.

3. What causes the B1788 code to appear?

Common causes include damage to the rear occupant classification sensor, wiring issues, a faulty sensor module, or previous collision damage.

4. Can I drive with the B1788 code active?

While the vehicle may still be drivable, this code can affect airbag system performance, which could compromise safety in an accident.

5. How is the B1788 code diagnosed?

A technician will use a scan tool to confirm the code, inspect the rear occupant classification sensor and its wiring, and check for any physical damage or loose connections.

6. How do you fix the B1788 code?

Repairs may involve replacing the faulty rear occupant classification sensor, repairing damaged wiring, or recalibrating the occupant classification system.

7. Can a reset clear the B1788 code?

Clearing the code without addressing the underlying issue will likely result in the code returning. Proper diagnosis and repair are necessary.

8. Does a past collision automatically trigger the B1788 code?

Not necessarily, but collision damage can affect the sensor or its wiring, leading to the code being stored.

9. Is the B1788 code specific to certain car brands?

This code is most commonly associated with vehicles using advanced airbag systems, but its specifics can vary by manufacturer.

10. How much does it cost to repair the B1788 code?

Repair costs vary depending on the issue, with sensor replacement typically costing $100-$300, plus labor fees.

Discuss the causes and fixes for B1788 OBDII Code

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