Alarm System Bypass

Introduction

Engine starting and running problems can be caused by a faulty alarm module on cars equipped with the factory alarm system. Because testing the alarm module directly is difficult, bypassing it is the most practical diagnostic step. This requires disconnecting the alarm module and installing two jumpers in the electrical connector plug.

Tools

• Two wire jumpers with spade connectors

Procedure

1. Locate the alarm module — a black box approximately the size of a pack of cigarettes:
   • Early 944s (pre-1985.5): Behind the radio in the back of the center console.
   • Late 944s: Behind the kick panel in the passenger's footwell, above the DME computer.
2. Disconnect the electrical plug from the alarm module.
3. Connect one jumper from Pin 1 to Pin 4 on the large module connector. Connect the second jumper from Pin 7 to Pin 8 on the large module connector.

Late 944 Alarm Module — Part Number 911.637.104.02

Plug Terminal #	Wire Color	Control Unit Terminal #
1	Black / White (0.5 mm)	15
2	Brown / Yellow (0.5 mm)	T
3	Brown (0.5 mm)	31
4	Green (0.5 mm)	87a
5	Yellow (0.5 mm)	E/A
6	Brown / Black (0.5 mm)	MK
7	Yellow / Red (0.5 mm)	61
8	Blue (0.5 mm)	61
1 (small plug)	Black / Red (1.0 mm)	HN
2 (small plug)	Red (1.5 mm)	30

Early 944 Alarm Module — Part Number 911.637.104.00

Plug Terminal #	Wire Color	Control Unit Terminal #
1	Green	15
2	Brown (2 wires)	T
3	Brown / White	31
4	Black	K1
5	Blue	E/A
6	Blue / White	MK
7	Brown / Black	61
8	Brown / Red	61
1	Red / Yellow	HN
2	Red	30

Late Alarm Module Wiring Diagram

4. Attempt to start the vehicle to verify the bypass was successful. If the car still does not start with the jumpers installed, the alarm module is not the cause of the no-start condition.