Audi Workshop Service and Repair Manuals > A4 Mk1 > Power unit | Motronic injection and ignition system (4-cyl.) | Self diagnosis, V.A.G Inspection Service | Readiness code

Mixture preparation system, electronic inj.,Gas > < Reading off readiness code

Motronic injection and ignition system (4-cyl.)

Readiness code

Generating readiness code

Special tools and workshop equipment required

◆ Speed regulator V.A.G 1788/10

Test requirements

● Engine not running
● Electrical consumers switched off (radiator fan must not run during the test)
● Coolant temperature at least 80°C

Work step 1: interrogate fault memory

‒ Connect vehicle diagnostic, testing and information system VAS 5051 (or fault reader V.A.G 1551) and select engine electronics control unit by entering address word "01" ( .)
When doing this the ignition must be switched on.

→ Indicated on display:

Rapid data transfer HELP

Select function XX

‒ Press keys 0 and 2 for the function "Interrogate fault memory" and confirm entry with Q key.

→ The number of faults stored or "No fault recognised!" will be shown on the display.

X Faults recognised!

If a fault is stored:

‒ Rectify fault and erase fault memory. Then take vehicle for a road test and interrogate fault memory once again to check for faults.

If no faults are stored:

‒ Press ⇒key.

Work step 2: erase fault memory

● Ignition switched on.

→ Indicated on display:

Rapid data transfer HELP

Select function XX

‒ Press keys 0 and 5 for the function "Erase fault memory" and confirm entry with Q key.

Note:

If the fault memory is erased, the readiness code is set back and therefore has to be regenerated.

→ Indicated on display:

Rapid data transfer ⇒

Fault memory is erased!

‒ Press ⇒key.

The readiness code can be generated in two ways:

● When the vehicle is driven under varying engine load conditions, the control unit carries out tests on the relevant parts of the emission control system, and in this way the readiness code is generated automatically.

● Generate the readiness code as follows:

Work step 3: diagnosis of fuel tank breather valve

Test conditions

● Engine idling
● Coolant temperature above 85°C (Display group 4, display zone 3)

→ Indicated on display:

Rapid data transfer HELP

Select function XX

‒ Press keys 0 and 4 for function "Basic setting" and confirm entry by pressing Q.

→ Indicated on display:

Introduction of basic setting Q

Enter display group number XXX

‒ Enter "070" for Display Group 070 and confirm entry with Q key.

→ Indicated on display:

System in basic setting 70 ⇒

1 2 3 4

‒ Check the readout in display zone 4:


	Display zones
	1	2	3	4
Display Group 070: Diagnosis of fuel tank breather valve
Display	xx %	xx.x %		---
Indicates	Fuel tank breather valve: degree of opening	Lambda control variation	Relative mass flow through tank breather valve	Diagnosis status
Range	min.: 0 % max.: 100 %	min.: -25.0 % max.: 25.0 %		Test OFF Test ON TBV OK TBV n. OK Abort
Specification	xx %	-2.5...2.5 %	xx...xx %	TBV OK
Note				If "TBV n. OK" appears on display, interrogate fault memory (=> Page 24-131.

If the specification "TBV O.K." is attained:

‒ Press C key.

Work step 4: diagnosis of fuel supply system

● Engine idling
● Lambda control function active

→ Indicated on display:

Introduction of basic setting Q

Enter display group number XXX

‒ Enter "107" for "Display group number 107" and confirm with Q key.

→ Indicated on display

System in basic setting 107 ⇒

1 2 3 4

‒ Check the readout in display zone 4:


	Display zones
	1	2	3	4
Display Group 107: Diagnosis of fuel supply system
Display	xxx rpm	x.x %		Test ON
Indicates	rpm (actual)	Lambda control mean value (bank 1)		Diagnosis status
Range	min.: 550 rpm max.: 7200rpm	-25.0 ... 25.0 %		Test OFF Test ON Syst. OK Syst. n. OK
Specification	600 ... 900 rpm	-23 %...23 %		Syst. OK
Note				If the display shows "Syst. n. OK", interrogate fault memory => Page 01-9.

If the specification "Syst. OK" is obtained in display zone 4:

‒ Press C key.

Work step 5: diagnosis of lambda probe heating

→ Indicated on display:

Introduction of basic setting Q

Enter display group number XXX

‒ Enter "041" for "Display group number 041" and confirm with Q key.

→ Indicated on display

System in basic setting 41 ⇒

1 2 3 4

‒ Check readouts in display zones 1 and 3:

Note:

The readouts can be obtained more quickly by increasing engine speed.


	Display zones
	1	2	3	4
Display Group 41: Lambda probe heating (at idling speed)
Display	xxx kOhm	Htg.bC.ON	xxx kOhm	Htg.aC.ON
Indicates	Bank 1, Probe 1	Status of heating	Bank 1, Probe 2	Status of heating
Range		Htg.bC.ON Htg.bC.OFF		Htg.aC.ON Htg.aC.OFF
Specification	less than 2 kOhm	Htg.bC.ON	less than 2 kOhm	Htg.aC.ON
Note

Important notes on Display group 41: display zones 1 and 3:

◆ Display zones 1 and 3 remain blank until the lambda probes reach operating temperature (increase engine speed to obtain the readouts).
◆ A resistance value below 0.9 kOhm should appear in display zones 1 and 3 when both lambda probes have reached operating temperature.
◆ Do not continue the test until display zones 1 and 3 show a resistance value below 0.9 kOhm.

‒ Press C key.

Work step 6: diagnose of ageing of lambda probe before catalytic converter

Test conditions

● Increase engine speed until the exhaust temperature in display zone 2 reaches 200°C.

→ Indicated on display:

Introduction of basic setting Q

Enter display group number XXX

‒ Enter "034" for "Display group number 034" and confirm with Q key.

→ Indicated on display

System in basic setting 34 ⇒

1 2 3 4

‒ Check the readout in display zone 4:


	Display zones
	1	2	3	4
Display group 034: Ageing of lambda probe before catalytic converter
Display	xxxx rpm	xxx °C	x.x s	Test ON
Indicates	Engine speed	Exhaust temperature	Cycle duration of lambda probe (before catalytic converter)	Status of diagnosis
Range	min.: 550 rpm max.: 7200rpm	70...850 °C	0.0...3.0 sec.	Test OFF Test ON B1-P1 OK B1-P1 n. OK
Specification	600...900 rpm	above 200 °C	0.1...1.0 sec.	B1-P1 OK
Note				If "B1-P1 n. OK" appears on display: interrogate fault memory => Page 01-9.

If the specification "B1-P1 OK" is obtained in display zone 4:

‒ Press C key.

Work step 7: diagnosis of condition of lambda probe after catalytic converter

● Engine idling

→ Indicated on display:

Introduction of basic setting Q

Enter display group number XXX

‒ Enter "036" for "Display group number 036" and confirm with Q key.

→ Indicated on display

System in basic setting 36 ⇒

1 2 3 4

‒ Check the readout in display zone 2:


	Display zones
	1	2	3	4
Display group 036: Condition of lambda probe after catalytic converter
Display	x.xxx V	Test ON
Indicates	Voltage of lambda probe after catalytic converter bank 1	Status of diagnosis
Range	0.000V...1.000 Volt	Test OFF Test ON B1-P2 OK B1-P2 n. OK
Specification	0.500...0.800 V	B1-P2 OK
Note		If "B1-P2 n. OK" appears on display: interrogate fault memory => Page 01-9.

If the specification is obtained:

B1-P2 OK in display zone 2

‒ Press C key.

Work step 8: diagnosis of lambda control system

● Engine idling

→ Indicated on display:

Introduction of basic setting Q

Enter display group number XXX

‒ Enter "037" for "Display group number 037" and confirm with Q key.

→ Indicated on display

System in basic setting 37 ⇒

1 2 3 4

‒ Check the readout in display zone 4:


	Display zones
	1	2	3	4
Display group 037: Lambda control system
Display	xx.x %	x.xxx V	xxx ms	Test ON
Indicates	Engine load	Voltage of lambda probe after catalytic converter	Lambda compensating value between lambda probe 1 and lambda probe 2	Status of diagnosis
Range	0...175 %	0.000...1.000 Volt	---	Test OFF Test ON Syst. OK Syst. n. OK
Specification	14...24 %	0.000...1.000 Volt	-800ms...800ms	Syst. OK
Note				If the display shows "Syst. n. OK", interrogate fault memory => Page 01-9.

If the specification "Syst. OK" is obtained in display zone 4:

‒ Press C key.

Work step 9: diagnosis of catalytic converter

→ Indicated on display:

Introduction of basic setting Q

Enter display group number XXX

‒ Enter "046" for "Display group 046" and confirm entry with Q key.

→ Indicated on display:

System in basic setting 46 ⇒

1 2 3 4

● Increase engine speed to approx. 3000 rpm until the exhaust temperature (display zone 2) reaches 550°C.

‒ Check the readout in display zone 4:

Note:

The diagnostic test of the catalytic converter takes approx. 60 seconds.


	Display zones
	1	2	3	4
Display group 046: Diagnosis of catalytic converter (bank 1)
Display	xxxx rpm	xxx °C	x.x s	---
Indicates	Engine speed	Exhaust temperature	Catalytic converter: conversion	Status of diagnosis
Range	min.: 550 rpm max.: 7200rpm	70...850 °C	0.0...1.0 sec.	Test OFF Test ON Cat B1 OK Cat B1 n. OK
Specification	1800..2200 rpm	400 ... 600°C	0.0...0.09 sec.	Cat B1 OK
Note				If "Cat B1 n. OK" appears on display, interrogate fault memory => Page 01-9. If there is no fault stored in fault memory, replace catalytic converter.

If the specification "Cat B1 OK" is obtained in display zone 4 :

‒ Press C key.

Work step 10: diagnosis of secondary air system

→ Indicated on display:

Introduction of basic setting Q

Enter display group number XXX

‒ Enter "077" for Display group 077 and confirm entry with Q key.

→ Indicated on display:

System in basic setting 77 ⇒

1 2 3 4

‒ Check the readout in display zone 4:

Note:

The diagnostic test of the secondary air system takes approx. 60 seconds.


	Display zones
	1	2	3	4
Display group 077: Diagnosis of secondary air system
Display	xxxx rpm	xx.x g/s	xx %	Test ON
Indicates	Engine speed	Air mass	Percentage variation from specified value for secondary air system	Status of diagnosis
Range	min.: 550 rpm max.: 7200rpm			Test OFF Test ON Syst. OK Syst. n. OK Abort
Specification	600...900 rpm	2.5 ... 4.5 g/s	-40 %...40 %	Syst. OK
Note				If the display shows "Syst. n. OK", interrogate fault memory => Page 01-9.

If the specification "Syst. OK" is obtained in display zone 4:

‒ Press⇒key.

Work step 11: reading off readiness code.

‒ Read off the readiness code () once again as an additional check.

Power unit
Motronic injection and ignition system (4-cyl.) / Self diagnosis, V.A.G Inspection Service
Readiness code
Generating readiness code

Mixture preparation system, electronic inj.,Gas > < Reading off readiness code

Audi Workshop Service and Repair Manuals

A4 Mk1

Power unit Motronic injection and ignition system (4-cyl.) / Self diagnosis, V.A.G Inspection Service Readiness code Generating readiness code

Power unit Motronic injection and ignition system (4-cyl.) / Self diagnosis, V.A.G Inspection Service Readiness code Generating readiness code

Power unit
Motronic injection and ignition system (4-cyl.) / Self diagnosis, V.A.G Inspection Service
Readiness code
Generating readiness code

Power unit
Motronic injection and ignition system (4-cyl.) / Self diagnosis, V.A.G Inspection Service
Readiness code
Generating readiness code