Toyota Yaris: Owner Maintenance / Key Battery Replacement
If the buttons on the smart key are inoperable and the operation indicator
light does not flash, the battery may be dead.
Replace with a new battery before the smart key becomes unusable.
The following conditions indicate that the battery power is low:
- The KEY indicator light (green) flashes in the combination meter for
about 30 seconds after the engine is switched OFF.
- The system does not operate and the operation indicator light on
the smart key does not flash when the buttons are pressed.
- The system’s operational range is reduced.
Replacing the battery at your Toyota dealer is recommended to prevent damage to the key. If replacing the battery by yourself, follow the
instruction below.
Replacing the key battery
- Press the knob and pull out the auxiliary key.

- Twist a tape-wrapped flathead screwdriver in the
direction of the arrow and
open the cover slightly.

- Insert the tape-wrapped flathead screwdriver into the
gap and slide it in the direction of the arrow.

- Twist the flathead screwdriver in the direction of the
arrow and remove the cover.

- Remove the battery cap,
then remove the battery.

- Insert a new battery with the
positive pole facing up, and
then cover the battery with
the battery cap.

- Close the cover.

- Reinsert the auxiliary key.
NOTICE
- Make sure the battery is installed correctly. Battery leakage
could occur if it
is not installed correctly.
- When replacing the battery, be careful not to touch any of the
internal circuitry and electrical terminals, bend the electrical terminals,
or get dirt in
the smart key as the smart key could be damaged.
- There is the danger of explosion if the battery is not correctly
replaced.
- Dispose of used batteries according to the following instructions.
- Insulate the plus and minus terminals of the battery using
cellophane or equivalent tape.
- Never disassemble.
- Never throw the battery into fire or water.
- Never deform or crush.
- Replace only with the same type battery (CR2025 or equivalent).
- Be careful not to allow the rubber ring
shown in the figure to be scratched or
damaged.
- If the rubber ring detaches, reattach it
before inserting a new battery.

Before performing battery maintenance, remove the battery cover
by pressing the tab.
WARNING
Wash hands after handling the battery and related accessories
Battery posts, terminals and related accessories contain lead and lead
compounds, chemicals known to the State of California to cause cancer and
reproductive harm...
For reasons of proper performance, safety, and better fuel economy, always
maintain recommended tire inflation pressures and stay within the recommended
load limits and weight distribution...
Other information:
DIAGNOSTIC TROUBLE CODE CHART Diagnostic Trouble Code Chart DTC No. Detection Item Trouble Area Link B102004 Central Gateway ECU System Internal Failure Central gateway ECU (network gateway ECU)
U117087 Lost Communication With Brake System Control Module(ch2) Missing Message
CAN main/branch bus lines or connector
Engine stop and start ECU
Brake actuator assembly
Central gateway ECU (network gateway ECU)
No...
DESCRIPTION The brake actuator assembly communicates with the ECM and engine stop and start ECU. When the brake actuator assembly does not receive data from the engine stop and start ECU, the engine stop and start ECU stores DTC U117087. DTC No. Detection Item DTC Detection Condition Trouble Area DTC Output from U117087 Lost Communication With Brake System Control Module(ch2) Missing Message No communication from the brake actuator assembly continues...
Categories

Smart key
Auxiliary key
Key code number plate
To use the auxiliary key, press the knob and pull out the auxiliary key
from the smart key.

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