Checking exhaust-gas recirculation valve -N18 — AUDI

ATJ
Special tools and workshop equipment required

V.A.G 1526 A
V.A.G 1527 B
V.A.G 1594 A
V.A.G 1598/31
VAS 5051 with VAS 5051/1

Checking internal resistance

Unplug connector -1- of EGR valve -2-.
Connect up multimeter for resistance measurement to valve.
Specification: 14 ... 20 ω

Note:

At room temperature the resistance is in the lower tolerance range; at operating temperature it is in the upper tolerance range.

If reading does not match specification:

Replace EGR valve -N18.

Checking power supply

Connect multimeter to measure voltage at contact 2 and earth.
Switch on ignition.
Specification: Approx. battery voltage

If reading does not match specification:

Check for open circuit in wiring and repair if necessary.

Checking actuation

Test requirement:

Vehicle diagnostic, testing and information system VAS 5051 connected; vehicle self-diagnosis and vehicle system "01 - Engine electronics" selected

Connect up voltage tester V.A.G 1527 B between contacts 1 and 2.

Readout on VAS 5051:

Enter diagnostic function "03 - Final control diagnosis" in selection -1-.
Actuate EGR valve -N18.

Readout on VAS 5051:

A -
1. control element being tested
1 -
EGR valve -N18
LED must flash slowly

Note:

Voltage testers with a low current input do not go out completely between actuation of engine control unit, but rather continue to glow slightly and become distinctly brighter on actuation.

Terminate function "03 - Final control diagnosis" by touching ◂ key.

Readout on VAS 5051:

Enter diagnostic function "06 - End output" in selection -1-.

If LED does not respond as described:

Remove rubber seal from plenum chamber cover in direction of arrow.
Remove plenum chamber cover -1- from the front.

Remove electronics box cover in plenum chamber -arrows-.

Carefully lever off retainer bar with screwdriver -arrow-.

Release connector lock -arrow- and unplug connectors -1- and -2- from control unit.

Connect test box V.A.G 1598/31 to cable harness connector. Actual engine control unit is not to be connected. Clip test box earthing clip onto chassis (not shown in diagram).

Attention:
So as not to destroy electronic components, select required measuring range before connecting test leads and observe test conditions.

Check for open circuit in the following wiring.

Connector / Contact · Test box V.A.G 1598/31 / Socket
1 · 61
2 · 1 or 2

If necessary, eliminate open circuit in wiring/short circuit.