For 1990-2009 cars

### Lock (Transmitter)

When a lock command is received from the transmitter, the remote keyless entry (RKE) module provides battery voltage through circuit 195R to the LOCK relay in the instrument panel junction block (IPJB). The LOCK relay coil, grounded by circuit 550A, energizes and causes the relay contacts to close. When the relay contacts close, battery voltage is provided through the LOCKS fuse, through the relay, and out of the IPJB to each of the door lock motors. The driver door lock motor is grounded in the RKE module through circuit 550R. The other door lock motors are grounded through the UNLOCK relay by the IPJB ground circuit 550A.

The Saturn Security System is automatically enabled when the LOCK button is pressed on the transmitter. The LOCK button can be pressed a second time for a horn chirp confirmation. If the LOCK button is pressed twice and any of the doors or the trunk are open, the horn will not chirp. Once armed, the starter circuit is disabled through the starter relay. The normally open relay will prevent battery voltage through CKT 5 from reaching CKT 575 (auto)/575A (man) to the starter solenoid. The starter relay will not be energized until the Saturn Security System is armed, and either of the following occur. Any door is opened, or the ignition lock cylinder is turned. The RKE module will monitor CKT 39R from the ignition switch. If battery voltage is present on CKT 39R with the system armed, The RKE module will trigger the alarm.

When the Saturn Security System is activated, the horn will chirp for 10 seconds (Pre-alarm). Following this 10 second pre-alarm warning, the horn will cycle at 1 Hz for 200 ms, the dome lamp will flash during the 10 second (pre alarm). The dome lamp will not flash during the 10 second pre-alarm. Full-alarm will continue until any button is pressed on the transmitter, or 2 minutes have passed, whichever occurs first.

### Lock (Switches)

The lock operation of the driver's and passenger's door switches is the same as when operated by the transmitter, except battery voltage is provided to either switch to the LOCK relay instead of by the RKE module.

### Unlock (Transmitter) Driver's Door

When an unlock command is received from the transmitter, the body control module provides battery voltage through circuit 694 to the driver door lock motor. The motor is grounded by circuit 295 going through the LOCK relay in the IPFB to ground through circuit 550.

The Saturn Security System is disabled when the UNLOCK button is pressed. If the horn chirp mode is enabled, the horn will chirp twice for confirmation that the Saturn Security System is disarmed.

### Unlock (Transmitter) All Doors Except Driver's Door

When a second unlock command is received from the transmitter within 5 seconds of the first unlock command, the remote keyless entry module provides battery voltage through circuit 194R to the UNLOCK relay in the IPJB. The UNLOCK relay coil, grounded by circuit 550A, energizes and causes the relay contacts to close. When the relay contacts close, battery voltage is provided through the LOCKS fuse, through the relay, and out of the IPJB to each of the door lock motors, in opposite direction of LOCK, except the driver's door lock motor. The door lock motors are grounded through the LOCK relay by the IPJB ground circuit 550A.

### Unlock (Switches)

The unlock operation of the driver's and passenger's door switches, excluding the driver's door unlock, is the same as when operated by the transmitter, except battery voltage is provided by either switch to the UNLOCK relay instead of by the remote keyless entry module. The driver's door unlock signal is detected by the RKE module, through circuit 194R. The remote keyless entry module provides battery voltage to the driver's door lock motor, in opposite direction of LOCK.

### Decklid/Liftgate

The circuit description for the decklid and liftgate is explained on the facing pages of DTC P1695 and DTC P1696.

### Dome Lamp

The circuit description of the dome lamp is explained in the Lighting section of this service manual.

### Horn

The circuit description of the horn is explained in the Horn section of this service manual.