A8L V8-4.2L (BFM) (2004)
Vehicle Speed Sensor: Testing and Inspection
Speed Signal, Checking
Recommended special tools and equipment
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VAG1526 multimeter or VAG1715 multimeter
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VAG1594 connector test kit
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Wiring diagram
Test requirements
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The respective fuses of Engine Control Module (ECM) -J623- must be OK.
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Battery voltage must be at least 11.5 Volts.
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Speedometer -G21- must be OK.
Test sequence
NOTE: To test speed signal, vehicle must be driven. Doing this requires a second person.
CAUTION:
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Test and measuring equipment must always be secured to the rear seat and operated from there by a second person.
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If test and measuring equipment is operated from the passenger seat, the person seated there could be injured in the event of an accident involving
deployment of the passenger-side airbag.
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Connect diagnostic tester See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Reading and Clearing Diagnostic
Trouble Codes/Scan Tool Connecting
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Start engine and let run at idle.
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Under address word 33, select "Diagnostic mode 1: Checking measured values."
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Select the measuring value "PID 13: Vehicle speed".
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Perform a road test, and have the 2nd person observe the indication on the display.
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Check specified value of the vehicle speed:
PID
Diagnostic text
Specified value:
13:
Vehicle speed
approx. vehicle speed
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End diagnosis and switch ignition off.
If no speed is indicated:
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Check DTC memory.
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Read readiness code. If DTC memory was erased, readiness code must be generated again