Volkswagen Workshop Service and Repair Manuals

Servicing ignition part

=> Repair group 28

Notes:

• ◆ Fuel hoses in engine compartment must only be secured with spring type clips. The use of clamp or screw type clips is not permissible.
• ◆ If the engine starts, runs for a short period and then stops, after fault finding, repairs or component tests, then the fault may lie with the immobilizer which is blocking the engine control unit. The fault memory must be interrogated and if necessary the control unit matched .
• ◆ The control unit for the fuel injection and ignition system is equipped with a fault memory. Before carrying out repairs, adjustment work and fault finding the fault memory must be interrogated and the vacuum connections checked (outside air).
• ◆ Components marked with * are checked via the self diagnosis.
  => Page 01-5 , interrogating fault memory
• ◆ Components marked with ** are checked via the final control control diagnosis => Page 01-28 .
• ◆ For trouble-free operation of the electrical components, a voltage of at least 11.5 V is necessary.
• ◆ Do not use sealants containing silicone. Particles of silicone drawn into the engine, will not be burnt in the engine and damage the Lambda probe.

Safety precautions

Rules for cleanliness => Page 24-20

Technical data => Page 24-21

Checking engine operation => Page 24-31

Self diagnosis and electrical check of Motronic injection and ignition system:

=> Rep.-Gr. 01

• Air cleaner
• ◆ Dismantling and assembling => Page 24-17
• Connector
• ◆ 4 pin
• ◆ For air mass meter (G70)
• ◆ Check Lambda probe heating voltage supply , Electrical checks, test step 4
• To activated charcoal filter solenoid valve 1 (N80)*/**
• ◆ Activated charcoal filter system

=> Repair group 20; removing and installing parts of the fuel supply system; servicing activated charcoal filter system

• Intake hose
• Crankcase breather pressure regulating valve

• Intake manifold - upper part
• ◆ First tighten to intake manifold lower part and then to both rear supports
  => Page 24-9 , Item 20
• ◆ Dismantling and assembling => Page 24-17
• Connecting hose
• Silencer
• ◆ For idling speed stabilization
• Connector
• ◆ Only disconnect or connect with ignition switched off
• Securing plate
• ◆ For Motronic control unit (J220)
• 10 Nm

• Motronic control unit (J220)*
• ◆ Location: in plenum chamber, right
• ◆ For injection system, Lambda control, knock control, activated charcoal filter solenoid valve 1, speed governing via fuel pump relay, idling speed stabilization, ignition and self diagnosis
• ◆ Check control unit coding => Page 01-3 connecting fault reader V.A.G 1551 and selecting engine electronics control unit
• ◆ On replacement, the control unit must be matched to the electronic immobilizer => Page 24-44
• To brake servo
• To air conditioner
• Retaining clip
• ◆ Check seated securely

• O ring
• ◆ Renew if damaged
• Coolant temperature sender (G62)*
• ◆ Black, with temperature gauge sender (G2)
• ◆ For Motronic
• ◆ Checking => Page 24-40
• ◆ If necessary before removing, release pressure from cooling system
• Connector
• ◆ 4 pin
• ◆ Wiring chamber 1 and wiring chamber 3 for G62
• 20 Nm
• Support
• ◆ Between intake manifold upper part and cylinder head
• Gasket
• ◆ Renew

• Intake manifold - lower part
• ◆ Dismantling and assembling => Page 24-16
• Supply hose
• ◆ White arrow
• ◆ Secure with spring-type clips
• ◆ From fuel delivery unit in fuel tank
• Return hose
• ◆ Blue arrow
• ◆ Secure with spring-type clips
• ◆ To fuel tank
• Engine speed sender (G28)*
• Spacer ring

• Lambda probe (G39)*, 50 Nm
• ◆ Fitting location: catalyst
• ◆ Only grease threads with "G5"; "G5" must not get into the slots on the probe body
• ◆ Check probe heating voltage supply via Lambda probe heater relay (J278), => Page 01-40 , electrical checks, test step 5
• ◆ Check Lambda probe heating at Lambda probe connector (white wiring) for continuity
• ◆ With ignition switched on check Lambda probe basic voltage between contacts 3 and 4
       Specification: Approx. 0.5 V
• Deflector
• To crankcase

• Hose
• ◆ To warm air collection plate on exhaust manifold

=> Repair group 26; Removing and installing parts of exhaust system

• Retaining ring
• Connector
• ◆ 4 pin
• ◆ For Lambda probe and Lambda probe heating
• ◆ Secured to rear engine mounting on right, in direction of travel