Toyota Fault Code

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B2799

Engine Cranks No Start / Security On

System

Immobilizer

Symptom

Engine Cranks No Start / Security On

Diagnosis & fix steps

LOGIC: Engine Immobilizer System Communication Line Error (ECM to IMB). ACTION: Inspect communications wire between Transponder Key ECU and Engine ECM. Perform communication synchronization jumper bridge (pins TC and CG on OBD port for 30 min key ON).

Red Seal field insights

Battery Deadlock: Jump-starting with dead batteries drops handshake encryption between the engine control module and key amplifier module, requiring a roll-code resync.

Same code keeps coming back?

That's a program problem, not a part problem. Book a 30-minute uptime review with Grant, a Red Seal Heavy Duty Technician.

Book an uptime review

Read before you touch anything

  • This is general reference information, not a repair manual. It is for trained, qualified technicians.
  • Fault codes, meanings and procedures vary by model, serial number and software version. Confirm the code and the procedure against the manufacturer's service manual before acting.
  • Follow the OEM service manual, torque specs and your site's safety procedures: lockout/tagout, block raised equipment, relieve hydraulic, fuel and air pressure, and let hot systems cool.
  • You use this information at your own risk. Adventure Mechanical and AM Fleet Integrity accept no liability for damage, injury, downtime or loss arising from its use.
  • Not affiliated with or endorsed by any manufacturer. Brand names are used only to identify the equipment a code applies to.

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