Testing auxiliary signals
Testing speed signal
Notes:
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◆ The road speed signal is generated by the speedometer sender -G22 (on the gearbox) and is processed in the dash panel insert.
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◆ The processed signal goes to contact 54 on the engine control unit and is used for idling speed stabilisation and for the damping of load change jolts when changing gear.
Test requirement:
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● Speedometer (including display) must be functioning properly.
Fault-finding:
=> Electrical system; Repair group 90
Test sequence
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‒ Connect vehicle diagnostic, testing and information system VAS 5051 (or fault reader V.A.G 1551) and select engine electronics control unit by entering address word "01" ( .)
When doing this the engine must be idling.
Warning: To avoid accident risks when road testing the vehicle with test equipment, always observe the relevant safety precautions =>
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