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SRS fault code

B0090-87: Left Front Sensor Not Reporting

When the Occupant Restraint Controller stops hearing from the left frontal acceleration sensor, it stores B0090-87. Nothing is arriving from that corner of the truck, so the module has no front crash input on the left side and shuts deployment down.

Circuit fault

What B0090-87 means

Front acceleration sensors report to the ORC on a schedule. The controller expects a message from the left sensor on every cycle and leans on it to decide whether a frontal impact is under way. A missing message means the controller heard nothing at all, which points at power, ground, the signal wire, or a sensor that has gone completely dark.

Missing message is a different complaint from a sensor reporting its own internal failure. Here the sensor may be in perfect shape and simply cut off from the module. Front sensors live in the most exposed part of the truck, ahead of the wheels and behind the bumper, so the wiring running out to them takes salt, spray, and collision damage long before the sensor wears out.

Common causes

Crash data or hardware fault?

Treat B0090-87 as a live wiring fault rather than a crash record. The ORC repeats its communication check every key cycle, so the code clears on its own once the sensor reports in again. Deployment data does not behave that way. It is latched after airbags fire, no scan tool will remove it, and that is the record our mail-in reset service erases.

Does our reset clear it?

Resetting the module will not make a silent sensor talk. The controller runs the same check on the next key cycle and writes the code again. Repair the connector or the broken wire, confirm the sensor reports in, and the lamp goes out on its own. Send the module to us when the truck also deployed and the ORC is carrying that crash record alongside this fault.

Which makes throw it

Our lookup lists B0090-87 under Ram. The base number B0090 names the left frontal sensor and the -87 tells you the complaint is a missing message rather than a specific short or open, so the same base code turns up with other suffixes on the same truck.

What to do next

Check power and ground at the sensor connector first, since a dead sensor and a broken feed look identical from the driver seat. Back probe the supply, verify the ground, then check continuity on the signal wire back toward the ORC. If the wiring is solid and the sensor still says nothing, the sensor is the part to replace. We sell genuine OEM front impact sensors and can check fitment by VIN at 501-988-0611. Related codes: B0090-49, B0095-49, B1050.

B0090-87 points at a circuit, not the module

Fix the circuit, then clear the code.

Trace the wiring and connectors first. If the module still holds the fault after the repair, mail it to us and we will clear it.

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