System Diagram

o9<ZLighting For Instruments And Controls:

WIRING DIAGRAM

Lighting For Instruments And Controls: Component Location:

COMPONENT LOCATION VIEW

Lighting For Instruments And Controls: Component ID:

COMPONENT ID
10 Lights switch on dashboard between steering wheel and driver's door.
16 Instrument lighting rheostat on dashboard between steering wheel and driver's door.
22A Main fuse board in the dashboard.
25 Hazard flashers switch beside the SID unit.
88 Switch for extra fog lights in switch assembly between steering wheel and driver's door.
91 Selector lever lamp in the centre console adjacent to the selector lever.
148 Ashtray illumination, front
154 Lighting in the heating and ventilation control panel.
161 Rear fog light switch in switch assembly between steering wheel and driver's door.
216 ACC control module in centre of dashboard.
220 Fan control on side of evaporator.
252 Switch for electrically heated driver's seat, in switch assembly on centre console.
253 Switch for electrically heated passenger's seat, in switch assembly on centre console.
282 Switch, headlamp beam adjustment, on dashboard between the steering wheel and driver's door.
267 Radio and cassette player in the centre
353 console.
375 Mobile telephone connection.
386 Switches for electric window lifts/electric sunroof, on the centre console between the front seats.
504 Control panel for heating and ventilation, on the centre console.
506 WINTER switch, beside gear selector lever.
518 TCS switch in switch assembly on centre console.
540 Main instrument display panel on the dashboard.
541 SID unit on the dashboard.
560 Ignition switch illumination.

33-Pin Connector
H33-3 Blue connector on the bracket below the left-hand A pillar.

Grounding Points
G14 Grounding point, left-hand front seat member, under the seat.
G24 Grounding point, right-hand front seat member, under the seat.
G33P Grounding point, connector bracket (Power) below the left-hand A pillar.
G33S Grounding point, connector bracket (Signal) below the left-hand A pillar.
G34P Grounding point, control module bracket (Power) below the right-hand A pillar.
G34S Grounding point, control module bracket (Signal) below the right-hand A pillar.

DESCRIPTION OF OPERATION
Instrument lighting rheostat 16 is equipped with a built-in electronic unit.

Current is supplied to the rheostat via fuse 29. Rheostat 16 steplessly varies the intensity of the lighting in connected components with the aid of a PWM signal.

Current From Pin 2 Is Supplied To The Following Components:
^ 540 Main instrument display panel
^ 541 SID unit

Current From Pin 3 Of The Rheostat Is Supplied To The Following Components:
^ 18 Lighting for main instrument display panel
^ 25 Hazard flashers switch
^ 91 Selector lever lamp
^ 148 Ashtray illumination
^ 216 Automatic climate control unit display lighting
^ 252 Switch for electrically heated driver's seat
^ 253 Switch for electrically heated passenger's seat
^ 353 Radio dial illumination
^ 375 Pre-wiring for mobile telephone installation
^ 506 WINTER switch (TCM)
^ 518 TCS switch
^ 537 TCM SPORT switch

Current From Pin 5 Is Supplied To The Following Components:
^ 10 Lights switch
^ 88 Switch for extra fog lights
^ 161 Switch for rear foglight
^ 282 Headlamp beam adjustment switch
^ 386 Switches, electric window lifts, electrically operated sunroof

Current From Pin 9 Is Supplied To The Following Components:
^ 154 Lighting, heater controls
^ 216 Control module, ACC

Illumination Of The Rheostat Itself Is Also Controlled.
The rheostat sends a "rheostat value" to the SID unit which uses it to control instrument and display lighting in various systems. The SID unit also uses the rheostat value to calculate the brightness of the display illumination.

FAULT DIAGNOSIS HINTS
1. Check that fuse 28 is intact and supplied with current.
2. Check that current is present on pin 7 of the rheostat.
3. Check that a PWM signal is present on pins 2, 3, 5 and 9 of the rheostat and that the pin connections and ground connections of every component are satisfactory.