Checking engine speed sensor -G28: Audi 2.6 (ABC, ACZ)

ACZ
Special tools and workshop equipment required

V.A.G 1526 A
V.A.G 1594 A
V.A.G 1598 A
V.A.G 1598/11

Installation position => Installation position overview - Page
24-5

Before carrying out the test, make sure that the sensor is correctly installed and firmly seated.

Checking internal resistance

Pull grey 3-pin connector off engine speed sensor

Connect multimeter between contacts 1 and 2 of sensor in order to measure resistance.
Specification: approx. 1 kω

If the specification is not obtained:

Fit a new engine speed sensor.
Connect multimeter between contacts 1 and 3 and 2 and 3 on sensor to measure resistance.
Specification: ∞ω (no continuity)

If the specified values are not obtained:

Fit a new engine speed sensor.

Checking wiring

With the ignition switched off, use adapter V.A.G 1598/11 to connect test box V.A.G 1598 A to connector B only of engine control unit (control unit remains disconnected) => Page
24-10
.

Check for open circuit and short to positive or earth in the following wiring connections:

Connector / contact · Test box V.A.G 1598 A / socket
1 (earth) · 38
2 (signal) · 37
3 (screening) · 36

Rectify any open/short circuit as necessary.

=> "Current Flow Diagrams, Electrical Fault Finding and Fitting Locations" binder

If no wiring fault is detected:

Remove starter.

=> Electrical system; Repair group 27; Removing and installing starter
Electrical system
Removing and installing starter

Slowly crank engine and check ring gear for concentricity and broken/damaged teeth; replace if necessary

If no fault is found:

Replace engine control unit => Page
24-13
.

Adjusting holder for engine speed sensor

Notes:

The holder for the engine speed sensor can be moved in slots. The position is set at the factory and must not be altered.

If the bolts have been accidentally slackened off and the holder moved, carry out the adjustment as follows:

Special tools and workshop equipment required

Special tool 3242

Special tool 3308

Work sequence

Move crankshaft in direction of engine rotation to cylinder no.1 TDC mark (notch -B- aligned with mark -A- )
Unscrew ignition timing sensor -G4 from the cylinder block on the left.

Note:

TDC hole is located exactly behind the sensor in the crankshaft (can be felt).

Warning
Do not rotate the crankshaft whilst feeling for the TDC hole with your finger - risk of injury.
crew crankshaft securing bolt 3242 into hole where sensor has been removed, and tighten.
Unscrew heat shield over engine speed sensor.
Remove engine speed sensor and unfasten holder.

Insert special tool 3308 in place of sensor, so that it engages in ring gear.
Screw on holder.

The remaining installation steps are carried out in the reverse sequence: