Toyota 89663-04B91 Firmware: Tacoma Throttle Control Calibration
Learn how Toyota 89663-04B91 relates to Tacoma engine control and the P211904 malfunction indicator light bulletin.
Toyota firmware 89663-04B91, listed in service records as calibration 8966304B9100, is an updated engine control calibration associated with a malfunction indicator light and diagnostic trouble code P211904. The code concerns throttle actuator control, the electronic system that positions the throttle valve to regulate air entering the engine.
In normal driving, the engine control module uses accelerator input and operating conditions to command the throttle. It also monitors the actuator and throttle response. If the control system detects a fault, it can illuminate the malfunction indicator light and store a diagnostic code for investigation.
What the Toyota service bulletins document
Toyota service bulletin T-SB-0043-20 lists 8966304B9100 as an updated calibration in connection with the malfunction indicator light and P211904. The bulletin covers 2016–2020 Tacoma models with the 2GR-FKS engine. That model range is the bulletin’s scope, not a guarantee that this calibration applies to every vehicle in it.
Toyota bulletin T-TCI-5349 also lists the calibration as updated for the 2016 Tacoma with the 2GR-FKS engine and identifies the same code and warning-light topic. Together, the records associate this firmware with engine control and a documented throttle-control diagnostic concern.
Practical context
The calibration is software used by the engine control module, rather than a replacement throttle component. Its updated status belongs to the bulletin’s repair context. The service records identify the warning light and code, but do not establish that every P211904 event is caused by calibration alone.
No stock or modified variant label is identified for this entry. Vehicle-specific applicability and diagnosis depend on the relevant service information and the vehicle’s existing calibration.