Audi A4 Workshop Service and Repair Manuals

Notes:

• ◆ Installation location of Hall sender .
• ◆ Hall sender -G40 is located at rear of left-hand cylinder head (bank 2).
• ◆ Hall sender -G163 is located at front of right-hand cylinder head (bank 1).

Checking activation of Hall sender

For following checks, use leads from adapter set V.A.G 1594.

• ‒ Push back rubber sleeve on relevant Hall sender connector.
• ‒ → Connect the V.A.G 1527 diode test lamp to contacts 1 and 2 on the Hall sender connector from behind (the connector remains attached to the Hall sender).

Note:

Receptacles are numbered accordingly on the back of the connector.

• ‒ Operate the starter for a few seconds.

The diode test lamp must flash briefly on each second engine revolution.

Note:

Diode test lamps with a low current draw continue to glow faintly between impulses from the engine control unit (rather than going out completely) and become much brighter when receiving an impulse.

If diode test lamp does not flash, check voltage supply.

Checking the power supply for the Hall sender.

• ‒ Disconnect connector from relevant Hall sender.
• ‒ Switch the ignition on.

• ‒ → Connect V.A.G 1526 hand-held multimeter (voltage measurement) to contact 1 on the relevant connector and engine earth.

• Specified value: approx. 5 V.

Checking signal line for Hall sender:

• ‒ → Connect V.A.G 1526 hand-held multimeter (voltage measurement) to contact 2 on the relevant connector and engine earth.

• Specified value: approx. battery voltage

Checking earth line for Hall sender:

• ‒ → Connect V.A.G 1598/31 test box to wiring harness leading to engine control unit; the engine control unit should not be connected .
• ‒ Connect V.A.G 1526 hand-held multimeter (resistance measurement) between contact 3 on the relevant connector and contact 108 in the test box.

• Specified value: Continuity.
• Wire resistance: max. 1.5 Ohm

If specified values are all achieved and the diode test lamp does not flash (measured between contacts 1 and 2 with starter connector attached),

• ‒ Replace relevant Hall sender.

If specified values are not attained, check wiring connections.

Checking the wiring between the Hall sender and engine control unit.

• ‒ Connect the V.A.G 1598/31 test box to wiring harness leading to engine control unit; the engine control unit should not be connected => Page 24-22.
• ‒ → Check the wiring from the Hall sender ...
• ‒ ...to engine control unit for checking for open circuit and short to positive or earth.

Hall sender (bank 2)

Hall sender (bank 1)

• Wire resistance: max. 1.5 Ohm

• ‒ Rectify any open/short circuit as necessary.

• ‒ If a trial erasure of the fault memory is followed by the replaced indication of a fault relating to the camshaft sensor (Hall sender) although all previous tests were OK, the following faults are possible:
• ‒ Rotor ring for Hall sender misaligned, check phase location.

Checking phase location of Hall sender

• ‒ Connect up vehicle diagnostic, testing and information system VAS 5051 or fault reader V.A.G 1551 and select engine electronics control unit with "Address word" 01 => Page 01-8.
  For this purpose, the engine must be running at idle speed

• ‒ Press keys 0 and 8 for the function "Read measured value block" and confirm entry with Q key.

• ‒ Press keys 0, 9 and 3 for "display group number 93" and confirm entry with Q key.

• ‒ Check specified results for Hall sender.