Troubleshooting Procedure:
Condition 1: The alarm chirps repeatedly when armed.
Cause: Incorrect wire harness installed.
Diagnosis: The dome light switch must be set in the middle position (door activated). Arm the system with the door open, then close the door. The siren should chirp once. If the chirping continues until the dome light is fully out, then the alarm was installed whh an incorrect wire harness.
Correction: Order 1991 Sonata Securby System Installation Kit, P/N: 00207-Y1000. Remove existing wire harness and replace with the new harness. Be sure to make the new T-tap connections as per Section E of the installation instructions.
Condition 2: The alarm will not always arm (one chirp and one flash), but when it does, it will not
trigger when the trunk is opened.
Cause: Two conditions will prevent the alarm from arming:
1. No power to alarm control module due to incomplete electrical connections.
2. Incomplete connections from alarm control module to trunk or door switches.
Diagnosis:
1. Try to arm system with the main alarm switch - the LED should glow steadily. If the LED does not illuminate, check to see that the switch is connected to the adapter cable, which is connected to the security system wire harness. If that is correct, check for correct ignition and battery voltage levels:
Connector Alarm Wire Vehicle Wire Voltage
M20 Red Yellow 12V Constant
M1-01 Yellow Yellow w/green 0V - IGN SW off
12V - IGN SW on
Also check that the black ground wire is tightly secured under the alarm module mounting bracket bolt (to the right of the steering column). If these voltage levels are correct, all connectors are connected, and the system still will not enter the valet mode, then enter the main alarm switch or the alarm control module is malfunctioning.
2. If the alarm enters the valet mode properly, but will not arm, then there is an input to the alarm module indicating either a door or the trunk is open.
Trunk input verification:
The alarm trunk input wire is a blue alarm wire connected behind the instrument cluster to the blue w/yellow stripe vehicle wire. The blue w/yellow stripe vehicle wire is routed to connector M07-5. Early Ulsan, Korea produced vehicles with VINS ending in MU256000 or lower, (VINS with MBXXXXXX are Canadian built) may have an extra blue w/yellow stripe wire in the same bunch. With the lower crash pad and the alarm module mounting bracket removed, look up behind the instrument cluster (I.C.). Near the speedometer cable, a wire harness bundle leads to the back of the I.C. Pull gently on the wire bundle until you can see the end of the sheath. The wires divide into two branches to connector M07-4 and M07-5. The connection should be to the blue w/yellow stripe wire that is routed with the blue w/red stripe wire to connector M07-5.
The door input verification:
The light green alarm wire connected to the blue w/black stdpe vehicle wire at the E.T.A.C. connector M80-1 is the door input. Be sure all doors are closed. Connect a test light between + 12v and this wire and then open one of the doors to be sure that the test light glows, indicating a ground signal.
Condition 3: The alarm will not always enter the valet mode, even though the switch is off (out).
Cause: Faulty main alarm control switch.
Diagnosis: Arm the alarm, turn the ignition key on to the ignition position to disarm the alarm, push the alarm button so it comes to its full out position (valet mode), then turn the ignition key off. If the LED on the alarm switch comes on and stays on, the system is in the valet mode and is operating properly. If the system chirps when the key is turned off, then it is not entering the valet mode. This is caused by a faulty alarm switch.
Correction: Remove the radio fascia panel to the remove and replace switch. Install 1991 Sonata Main Control Switch P/N - 00207-Y1020.