PRE-RELEASE
Speed, wire from ABS
| Speed, wire from ABS |
The ABS control module sends a speed signal to pin 64 on the Trionic T7 control module. The signal is a square wave that varies between 0 V and B+ 29 times per wheel revolution. This speed signal is used to:
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prevent adaptation of idle speed control when the car is moving.
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on manual gearboxes, determine which gear is currently being used. This makes it possible to limit torque in gears R and 1 and activate fuel shut-off in gears 2, 3, 4 and 5. Control of the SHIFT UP lamp also depends on the current gear.
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activate speed limitation, which is achieved by limiting the maximum air mass/combustion at 250 km/h for B235R and 240 km/h for B205L/R.
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| Diagnostics |
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If the speed signal is missing, diagnostic trouble code P0502 will be generated.
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If the speed value is implausible, diagnostic trouble code P0501 will be generated.
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System reaction to a fault
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Speed (bus from MIU) used as substitute value.
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Cruise control blocked.
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