Workshop Manuals Factory service & repair Alfa Romeo
01 145 electrical system diagnosis02 146 electrical system diagnosis03 ABS, Alfa Romeo Code and engine management
Alfa Romeo 145/146 Electrical System Diagnosis Manual, Volume 3 (1994-2001)02 · 146 electrical system diagnosis
02 · Diagnostics

FUNCTIOnAL DESCRIPTION

Make
Alfa Romeo
Model
145/146 Electrical System Diagnosis Manual, Volume 3
Year
1994–2001
Section
Anti Theft device › FUNCTIOnAL DESCRIPTION
146 electrical system diagnosisFUNCTIOnAL DESCRIPTION

FUNCTIOnAL DESCRIPTION

The anti-theft system is controlled by electronic control unit N45 integrated with the siren and the emergency key.

The control unit is supplied directly by the battery at pin A3; the key-operated supply reaches pin B12. Through fuse F1 of fusebox G1 pin B7 is supplied (blinker supply).

Pin A9 is earthed (G53b).

The system activation signal is sent from the receiver N67 to pin A2 of the control unit; the same serial connection line is used to control the volumetric sensors, inserted with the receiver inside the ceiling light.

Through the receiver N67 door opening/closing is controlled, by means of the door lock control unit N11 of fusebox G1 (for further details see "Door locking System").

The control unit controls the closing of doors and bonnets via switches P10, P11, P12 and P13 of the doors (which are the same for the door locking device) which send an earth respectively to pins B8, B9, B15 and B16. The bonnet is controlled by switch H44, which is connected at pin B18, and the luggage compartment by switch H24 (the same that turns on the luggage compartment light) which is connected at pin B17.

In addition to the closing of the doors, carried out directly by the receiver N67, the control unit activates the blinkers (hazard warning lights flashing) sending an intermittent signal: from pin B1 for the right-hand lights and from pin B2 for the left-hand lights.

Pin A1 of the control unit sends a duty-cycle signal to led D31 when conditions so require.

ONLY FOR VERSIONS WITHOUT ALFA ROMEO CODE : the anti-theft system "intercepts" the key in the STARTING position signal (pin B6) which is "referred" to the starter motor A11 (from pin B5) only if the system is not in an alarm condition.

In addition, in the case of alarm, the injection control unit supply is inhibited; this supply (12 V) reaches pin B4 and it is "returned" by pin B3 (Boxer 1.3 and 1.6 versions).

Pin A10 sends a specific block signal to the control unit (only Boxer 1.7 16V version). For further details see the sections concerning engine ignition/injection.

For the TD version, the key-operated supply for the engine stop solenoid valve and glow plugs reaches pin B4, and it is "returned" by pin B3. For further details see "TD engine control devices".

Lastly the system can be connected with the Alfa Romeo Tester through connector T7; the diagnosis signal - line K - leaves from pin A6 of the control unit.

Anti-theft control unit and receiver N67 diagram

ANTI-THEFT CONTROL UNIT PIN-OUTS

A1 Signalling led control

A2 Serial connection line with receiver (ceiling light)

A3 Direct supply

A4 N.C.

A5 N.C.

A6 Diagnosis line K

A7 N.C.

A8 N.C.

A9 Control unit earth

(*) A10 Engine control inhibition (only for Boxer 1.7 16v)

A11 N.C.

A12 N.C.

B1 RH direction indicators control

B2 LH direction indicators control

(*) B3 Fuel pump/injection supply consensus (Boxer 1.3 and 1.6) - "key-operated" supply for engine electric stop and glow plug warming (TD)

(*) B4 Fuel pump/injection supply consensus (Boxer 1.3 and 1.6) - "key-operated" supply for engine electric stop and glow plug warming (TD)

(*) B5 Starter motor supply

B6 STARTING signal from ignition switch

B7 Blinker supply

B8 LH front door open signal

B9 RH front door open signal

B10 N.C.

B11 N.C.

B12 "Key-operated" supply

B13 N.C.

B14 N.C.

B15 RH rear door pen signal

B16 LH rear door open signal.

B17 Tailgate open signal

B18 Tailgate closed signal

(*) Connected only for versions without ALFA ROMEO CODE

Parts & tools for this job For 1994 Alfa Romeo 145/146

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