Steering Column

All the stuff in the steering column

There’s a lot of logic hard-coded into the switches. Logic that has to be decoded to determine the actual position of the switch.

Ignition Switch 30 → 15 ignition on 30 → 50 cranking

Indicator Stalk: Hi/Low beam/Flash 30 → 56a when flashing 56 → 56a on high beam 56 → 56b on low beam

Indicator Stalk: Direction and Emergency Flash 30(q) → 59 Emergency Flash 30(q) → 49a via K6 49a flash “sink” P → PL Indicate Left P → PR Indicate Right

Cruise Control 4 → 3 Set 4 → 2 Resume? 4 → 1 Cruise

Wash/Wipe and Horn Speed 53b 53 J Fast 53a - - Normal - 53a - Tip - 53a - Off - - - Intermittent - - 53a 53a → H Wash front 53a → T Wash rear 71 → 31 Horn

MFA Function and Memory Select T4d/1 is Common (high) 4d/2 Mode switch Line R1 1 2 R2 3 1 1 0 0 4 1 0 0 1

Summary of I/O

Switch Block	Inputs	Outputs
Ignition Switch (D)	30↑ logic common high	15↑ and 50
Indicator Stalk (E2 E3 E4 E19) with Emergency Flash (K6)	30↑ supplies power to K6 56 and P tied as logic input	49a (sinks flashing). 49↑, 56a, 56b, PL and PR
Cruise Control	4 as logic input (high)	1, 2 and 3
Wash/Wipe and Horn (E22 H)	53a logic common (high). 71↑ to battery	31↑, 53b, 53, J, H and T
MFA Function and Memory Select (E86 E109)	1 logic input (high)	2, 3 and 4

Inputs marked ↑ must remain high, even when the node goes to sleep to conserve the battery. Outputs marked ↑ will cause the node to wake up from sleep mode, in addition to other events.

The slave node will go to sleep when told to do so by the LINbus master.

The slave node controller will be able to manage with just one (1) switched output as a logic input for switch sensing and one (1) output for driving the flashing emergency indicator lamp in the steering column. A total of 20 logic inputs are required to resolve all possible switch positions.

Anti-theft immobilization can be implemented by blocking the starting of the engine by not setting the state of terminal 50 to on in the device status, preventing a start of the engine by key; and by setting the immobilizer block status bit. The latter can be used to flash an idiot light in the dashboard, showng that starting was blocked by the immobilizer.