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Home >> Volkswagen >> 1999 >> New Beetle (1C1) L4-1.8L Turbo (APH) >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Testing and Inspection >> Component Tests and General Diagnostics >> Speed Signal, Checking >> With Manufacturer's Scan Tool

With Manufacturer's Scan Tool



Speed Signal, Checking

Special tools, test equipment and auxiliary items
- Scan tool VAG 1551 or vehicle system tester VAG 1552 with cable VAG 1551/3B
- Test box VAG 1598/31
- Hand multimeter VAG 1526 or multimeter VAG 1715
- Adapter set VAG 1594
- Wiring diagram

Check conditions






- Fuses 5,10 and 29 must be OK
- The battery voltage must be at least 11.5 V
- Speedometer must be OK.,

Test sequence

NOTE: To check the speed signal the vehicle must be driven. To do this a second person is necessary.

WARNING: During a road test in an airbag-equipped vehicle, test equipment must always be fastened to and operated from the rear seat by a second technician.

- Connect scan tool VAG 1551 (VAG 1552). Start engine and select "Address word" 01 of engine control module. When doing this the engine must be running at idle speed. Connecting scan tool and selecting Engine Control Module (ECM). Refer to "Scan Tool Testing/Scan Tool Connecting and Initial Checks/VAG 1551 Scan Tool", Testing and Inspection

Indicated on display

Rapid data transfer HELP
Select function XX

- Press keys 0 and 8 for the function "Read measuring value block" and confirm entry with Q key.

Indicated on display

Read measuring value block
Input display group number XXX

- Press keys 0, 0 and 5 for "Display group number 5" and confirm entry with Q key.

Indicated on display (1-4 = Display zones)

Read measuring value block 5 ->
1 2 3 4

- Carry out test drive with a 2nd person to observe display.

Observe the valid safety precautions when carrying out a road test.

- Observe figure displayed in display zone 3:
Specification: approx. driven speed

Display Group 5:






- Press the -> key.
- Press keys 0 and 6 for the "End output" function and confirm input with the Q key.
- Switch off ignition.

Continuation

If no speed is displayed:
- Remove inner plenum chamber cover, left:






- Connect test box V.A.G 1598/31 to control module wiring harness. The engine control module is not connected by this action.
- Connect multimeter to measure voltage between test box sockets 2 + 20.
- Switch on ignition.
- Lift vehicle at front left.
- Rotate front wheel and observe voltage display.
Specification: between 0 and at least 4 Volt fluctuating

NOTE: If necessary, hold the front right wheel to prevent it from turning.

If the display does not fluctuate:
- Check wiring to speedometer/speedometer sensor.
- Check DTC memory, if necessary, repair any malfunctions and then erase DTC memory, checking and erasing DTC memory. Refer to "Displaying, Reading and Erasing Trouble Codes/With Manufacturers Scan Tool/DTC Memory, Checking And Erasing", Testing and Inspection
- Read-out the readiness code. If the DTC memory has been erased or the engine control module was disconnected from permanent positive, the readiness code must be generated again.
Refer to "Monitors Trips and/or Drive Cycle/Displaying Readiness Code", Testing and Inspection
Refer to "Monitors Trips and/or Drive Cycle/Generating Readiness Code", Testing and Inspection
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