For 1990-2009 cars

Do not connect aftermarket accessories into the following circuits:

Caution: Refer to SIR Warning in the Preface section.

• | SIR circuits--All such circuits are indicated on circuit diagrams with the SIR symbol.

Caution: Refer to OBDII Symbol Description Caution in the Preface section.

• | OBD II circuits-- All such circuits are indicated on circuit diagrams with the OBD II symbol.

Always check for aftermarket accessories (non-OEM) as the first step in diagnosing electrical problems. If the vehicle is so equipped, disconnect the system to verify that these add-on accessories are not the cause of the problems.

Possible causes of vehicle problems 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.