Some customers with a 1998-2003 Sienna may complain of a low battery or no-start condition after running the engine at idle or low RPM for extended ­periods of time with several accessories on during high-temperature conditions.

A new alternator has been developed to improve charging performance at idle.

Note: This new alternator will not prevent dead batteries or no-start conditions on vehicles that are stored for long periods of time or on vehicles that are driven very infrequently.

Repair Procedure:

Note: Confirm that the vehicle does not have an ­unusual parasitic load on the battery with key off and doors locked. Parasitic load should be less than 40 mA.
Figure 1

1. Disconnect the negative terminal from the vehicle battery.
Figure 2

2. Disconnect the alternator wire and connector. See Fig. 1.

3. Remove the drive belt and original alternator. See Fig. 2.
Figure 3

a. Pull up the retainer in the waterproof connector to disengage the secondary lock. See Fig. 3.

b. Release the locking lug from the terminal and pull the terminal out from the backside of the con...