Checking Engine Speed Sensor Audi A8 D3

Component location of connector. See COMPONENT LOCATIONS, OVERVIEW .

Scheme 12

1. Before performing test, make sure that sensor is correctly installed and firmly seated.
2. Check sensor and sensor wheel for damage and make sure they are not obstructed by metal particles. NOTE: Thickness of spacer between sensor and transmission should be 4.5 mm.
3. Disconnect harness connector for engine speed sensor (gray connector).
4. Connect multimeter (Fluke 83 or equivalent) (resistance test range) to terminals 2 and 3 on connector for engine speed sensor using test lead from VAG1594 connector test kit. Specification: approx. 450 to 1000 ohm

Note. The resistance value for the engine speed sensor is based on a temperature of 20 °C. The resistance increases as the temperature rises.

If the specification is not attained

1. Replace engine speed sensor.

If the specification is attained

Scheme 13

1. Connect multimeter (Fluke 83 or equivalent) (resistance test range) between terminals 2 and 1 (Ground (GND)) and between terminals 3 and 1 (Ground (GND)). Specification: Rohms (infinite Ohms / open circuit) in each test

If the specification is not attained

1. Replace engine speed sensor.

If the specification is attained

Scheme 14

1. Check wiring between sensor connector and engine control module as follows
2. Connect VAG1598/31 test box to wiring harness for engine control module. Do not connect to engine control module itself. See «WIRING AND COMPONENT CHECK WITH VAG1598/31 TEST BOX»(ref-216438-S11057563412006020800000) .
3. Check wiring connection from 3-pin connector (sensor connector) to engine control module for open circuit and/or short circuit to B+ or Ground (GND). ENGINE SPEED SENSOR CIRCUIT TEST - OPEN CIRCUIT AND/OR SHORT CIRCUIT SPECIFICATIONS 3-pin connector on wiring harness, contact Socket on VAG1598/31 test box 1 (shielded) 108 2 (Ground (GND) wire) 90 3 (signal wire) 82 Resistance in wiring: max. 1.5 ohm See SYSTEM WIRING DIAGRAM .
4. Repair any open/short circuit as necessary.

If no malfunctions are identified in the wiring

1. Slowly turn engine over and check that sensor wheel has no run-out and is securely mounted.
2. If no malfunctions have been identified in any tests so far, replace Engine Control Module (ECM). See «MOTRONIC ENGINE CONTROL MODULE (ECM) -J220- (WITHOUT METAL ANTI -THEFT HOUSING), REPLACING»(ref-216438-S07554723402006020800000) .
3. Display readiness code. See «READINESS CODE, CHECKING»(ref-216437-S40758807032006020800000) . If DTC memory was erased generate readiness code. See «READINESS CODE, GENERATING»(ref-216437-S25676712792006020800000) .