For 1990-2009 cars

Do not connect aftermarket accessories into the following circuits:

Warning: Refer to SIR Warning in the Preface section.

• | SIR circuits, all such circuits are indicated on circuit diagrams with the SIR symbol.

• | Always check for aftermarket accessories as the first step in diagnosing electrical conditions. If the vehicle is so equipped, disconnect the aftermarket system to verify that these add-on accessories are not the cause of the customer concern.

Possible causes of vehicle conditions related to aftermarket accessories include:

• | Power feeds connected to points other than the battery.

• | Antenna location.

• | Transceiver wiring located too close to vehicle electronic modules or wiring.

• | Poor shielding or poor connectors on antenna feed line.

• | Check for recent service bulletins detailing installation guidelines for aftermarket accessories.