SID Unit Power Supply and Ground

SID Unit Power Supply

SID Unit Power Supply:

Battery Voltage +30
Current (+30 circuit) is supplied via fuse 34 (22a) to pin 15 of the SID unit connector.

Battery Voltage +15
Current (+15 circuit) is supplied via fuse 17 (22a) to pin 8 of the SID unit connector.

The SID unit is activated by current from the +15 circuit.

Diagnostics
If no current from the +30 circuit is present, the display will not be active and diagnostic communication will not be possible.

If no current from the +15 circuit is present, the display will be off but can be activated via the bus, by turning on the radio for example. Diagnostic communication is possible with limited functions if the ignition is turned ON.

The SID unit will not generate a diagnostic trouble code if no current from either the +30 or +15 circuits is present.

SID Unit Ground

SID Unit Ground:

Ground connection
The SID unit is grounded via pin 1 at grounding point G34S.

Diagnostics
If there is no ground connection, the display will not be active and diagnostic communication will not be possible.

The SID unit will not generate a diagnostic trouble code if there is no ground connection.