Skoda Workshop Service and Repair Manuals

Display groups 010...041 and 099 Display group 010 ignition: For engine with engine identification characters ARZ

l  Engine runs in idling speed
Read measured value block 10 →				⇐ Readout on display
xxxx rpm	xx %	x.x %	xx ° b.TDC
1	2	3	4	⇐ Display fields	Specification	Analysis
				Ignition angle	6...12 ° b TDC	---
			Throttle valve angle		0,2...4,0 %	→ Anchor
		Engine load			15...25 %	→ Anchor
	Idling speed				---	→ Anchor

Test table - Display group 010

Display field	Display -V.A.G 1552-	Fault cause	Rectifying fault
2	less than 15 %	t  lower value can only occur during trailing throttle driving
	greater than 25 %	t  poor idling (engine not running on all cylinders)	–  Injection valves or spark plugs faulty
		t  Electrical consumers on	–  Switch off consumers
		t  Steering wheel at limit stop	–  Put steering wheel in centre position
		t  Gear engaged (automatic gearbox)	–  Put selector lever in P or N
		t  Air mass meter faulty -G70-	–  Test air mass meter -G70-
3	greater than 5 ∠°	t  Adaptation of the engine control unit to the throttle valve control unit not carried out	–  Adapt the engine control unit to the throttle valve control unit → Chapter
		t  Throttle valve potentiometer in throttle valve control unit faulty	–  Inspecting throttle valve control unit → Chapter
		t  Throttle valve jams	–  Remove fault

Display group 014, ignition-misfiring detection: For engine with engine identification characters ARX and AUM

l  Engine runs in idling speed
Read measured value block 14 →				⇐ Readout on display
xxxx rpm	xx.x %	x	Text
1	2	3	4	⇐ Display fields	Specification	Analysis
				Status of misfiring detection (activated, deactivated)	activated	---
			Total of ignition misfirings		0	→ Anchor
		Engine load			12,7...30,0 %	---
	Idling speed				---	→ Anchor

Display group 015, ignition - cylinder misfiring 1...3 For engine with engine identification characters ARX and AUM

l  Driving
Read measured value block 15 →				⇐ Readout on display
x	x	x	Text
1	2	3	4	⇐ Display fields	Specification	Analysis
				Status of misfiring detection (activated, deactivated)	activated	---
			Ignition misfiring cylinder 3		0	→ Anchor
		Ignition misfiring cylinder 2			0	→ Anchor
	Ignition misfiring cylinder 1				0	→ Anchor

Display group 016, ignition - cylinder misfiring 4: For engine with engine identification characters ARX and AUM

l  Normal driving
Read measured value block 16 →				⇐ Readout on display
x	-	-	Text
1	2	3	4	⇐ Display fields	Specification	Analysis
				Status of misfiring detection (activated, deactivated)	activated	---
			No meaning		---	---
		No meaning			---	---
	Ignition misfiring cylinder 4				0	→ Anchor

Analysis of display group 014, display field 3 and display groups 015 and 016, display fields 1, 2 and 3

Display -V.A.G 1552 -	Possible cause of fault	Rectifying fault
greater than 0	t  Spark plug defective t  Ignition coil defective t  Power stages if ignition coil defective	–  Inspect spark plugs –  Test ignition coil
	t  Injection valve defective	–  Testing injection valves

Display group 020, ignition - knock control: For engine with engine identification characters ARX and AUM

l  Normal driving
Read measured value block 20 →				⇐ Readout on display
xx.x °KW	xx.x °KW	xx.x °KW	xx.x °KW
1	2	3	4	⇐ Display fields	Specification	Analysis
				Ignition angle relief cylinder 4 through knock control	0.0...12.0 °KW	→ Anchor
			Ignition angle relief cylinder 3 through knock control		0.0...12.0 °KW	→ Anchor
		Ignition angle relief cylinder 2 through knock control			0.0...12.0 °KW	→ Anchor
	Ignition angle relief cylinder 1 through knock control				0.0...12.0 °KW	→ Anchor

Note t  Regarding display fields 1 ... 4: t  At idling speed the displayed value is 0.0 KW. Analysis of display group 020, display fields 1 ...4 - Ignition angle relief

Display -V.A.G 1552 -	Possible cause of fault	Rectifying fault
all cylinders greater than 12,0 °KW	t  Knock sensor defective	–  Testing knock sensors
	t  Plug connection corroded
	t  Knock sensor not correctly tightened	–  Slacken knock sensor and tighten again to 20 Nm
	t  Component parts on engine loose	–  Attach component parts
	t  poor fuel quality	–  Change type of fuel
one cylinder clearly deviates from the others	t  Plug connection corroded	–  Testing knock sensors
	t  Engine damaged	–  Testing compression: → 1.8 litre/110 kW engine, mechanics; Rep. Gr. 15
	t  Component parts on engine loose	–  Attach component parts

Display group 022, ignition: For engine with engine identification characters ARZ

l  Normal driving
Read measured value block 22 →				⇐ Readout on display
xxxx rpm	xxx %	xx,xx °KW	xx,xx °KW
1	2	3	4	⇐ Display fields	Specification	Analysis
				Ignition angle relief cylinder 2 through knock control	0...12,75 °KW	→ Anchor
			Ignition angle relief cylinder 1 through knock control		0...12,75 °KW	→ Anchor
		Engine load			15...175 %	---
	Engine speed (normal driving) manual gearbox automatic gearbox				700...6800 rpm 640...6800 rpm	---

Note t  Regarding display fields 3 and 4: t  At idling speed the displayed value is 0.0 KW. Display group 023, ignition: For engine with engine identification characters ARZ

l  Driving
Read measured value block 23 →				⇐ Readout on display
xxxx rpm	xxx %	xx,xx °KW	xx,xx °KW
1	2	3	4	⇐ Display fields	Specification	Analysis
				Ignition angle relief cylinder 4 through knock control	0...12.75 °KW	→ Anchor
			Ignition angle relief cylinder 3 through knock control		0...12.75 °KW	→ Anchor
		Engine load			15...175 %	---
	Engine speed, display group 022				---	→ Anchor

Note t  Regarding display fields 3 and 4: t  At idling speed the displayed value is 0.0 KW. Analysis of display groups 022 and 023, display fields 3 and 4 - ignition angle retardation

Display -V.A.G 1552 -	Possible cause of fault	Rectifying fault
all cylinders greater than 12.75 °KW	t  Knock sensor defective	–  Testing knock sensors
	t  Corrosion at plug connection
	t  Knock sensor not correctly tightened	–  Slacken knock sensor and tighten again to 20 Nm
	t  Component parts on engine loose	–  Attach component parts
	t  poor fuel quality	–  Change type of fuel
one cylinder clearly deviates from the others	t  Corrosion at plug connection	–  Testing knock sensors
	t  Engine damaged	–  Testing compression: → 1.8 l/110kW Engine, Mechanics; Rep. Gr.15
	t  Component parts on engine loose	–  Attach component parts

Display group 028, ignition: For engine with engine identification characters ARZ

l  Driving
Read measured value block 28 →				⇐ Readout on display
xxxx rpm	xxx %	xxx °C	Text
1	2	3	4	⇐ Display fields	Specification	Analysis
				Result of knock sensor test (Test on / Test off / Syst. o.k. / Syst. not o.k.).	Syst. o.k.	---
			Coolant temperature		40...110 °C	---
		Engine load			15...175 %	---
	Engine speed				2200...6800 rpm	---

Display group 030, Lambda control: Continued for all engines

l  for engine with engine identification characters ARX, AUM: Control unit in function 04 “Initiate basic setting” l  for engine with engine identification characters ARZ: Control unit in function 08 “read measured value block”
Read measured value block 30 →				⇐ Readout on display
xxx	xxx	---	---
1	2	3	4	⇐ Display fields	Specification	Analysis
				No meaning	---	---
			No meaning		---	---
		Status lambda control downstream of catalytic converter			110	→ Anchor
	Status lambda control upstream of catalytic converter				111	→ Anchor

Note t  Read off catalytic converter temperature at least 352°C t  The first position in the 3-digit numerical block changes initially between 0 and 1 (lambda probe heater OFF and ON).   Note t  Re display field 2: t  The third position of the display number changes to 1 under load. Meaning of 3-digit numerical block in display fields 1 and 2:

1	2	3	Meaning, if display positions = 1
		1	Lambda control active
	1		Lambda probe operational
1			Lambda probe heater switched on

Display group 032, lambda control (lambda learned values): Continued for all engines

Read measured value block 32 →				⇐ Readout on display
xx.x %	xx.x %
1	2	3	4	⇐ Display fields	Specification	Analysis
				No meaning	---	---
			No meaning		---	---
		Lambda learned value at partial load (multiplicative)			-10,0...10,0 %	→ Anchor
	Lambda learned value at idling speed (additive)				-10...10 % → Note -6,0...6,0 % → Note	→ Anchor

1)  Valid for engine with engine identification characters ARZ 2)  Valid for engine with engine identification characters ARX, AUM.   Note t  Regarding display fields 1 and 2: t  Low readouts indicate that the engine is running too rich and the lambda control therefore produces a leaner mixture. t  High readouts mean that the engine is running too lean and the lambda control therefore produces a richer mixture. t  If the control unit is dead all initialisation values are reset. t  add = additive - The effect of the fault (e.g. unmetered air) becomes increasingly less as engine speed rises. In the case of an additive initialisation value the injection period is changed by a fixed rate. This rate is independent of the basic injection period. t  mul = multiplicative - The effect of the fault (e.g. faulty injector) becomes greater as engine speed rises. The multiplicative learned value is a percentage change in the injection period. This change is dependent on the basic injection period. t  Initiate learning process: Control unit in basic setting (address word 04) t  Initialisation conditions for idling: Idling, coolant temperature at least 75°C, intake air temperature max. 90°C. t  Initialisation conditions at partial load: Coolant temperature at least 75°C, intake air temperature max. 90°C. Analysis of display group 032, display fields 1 and 2 - lambda learned values

Display -V.A.G 1552 -	Possible cause of fault	Rectifying fault
low learned values	t  low learned values in idling at normal lambda partial load learned values: Oil dilution (higher fuel content in the oil) possible	–  Disappears after driving on motorway or changing oil
	t  Injection valve leaks	–  Testing injection valves
	t  Fuel pressure too high	–  Test fuel pressure regulator and system pressure → Chapter
	t  Solenoid valve for activated charcoal filter constantly open	–  Testing solenoid valve for activated charcoal filter → Chapter
	t  Air mass meter faulty	–  Test air mass meter
	t  Lambda probe heating defective or lambda probe dirty	–  Check lambda probe heater
high learned values	t  high learned values in idling at less high lambda learned values in partial load: Unmetered air in intake manifold region possible	–  Inspect intake system for leaks → Chapter
	t  Injection valve leaks	–  Testing injection rate → Chapter
	t  Display fields 1 and 2: Air mass meter faulty	–  Test air mass meter
	t  Fuel pressure too low	–  Test fuel pressure regulator and system pressure → Chapter
	t  Unmetered air between air mass meter and throttle valve	–  Eliminate unmetered air
	t  Unmetered air at the manifold gasket	–  Eliminate leak
	t  Lambda probe heating defective or lambda probe dirty	–  Check lambda probe heater → Chapter

Display group 033, lambda control (lambda learned values) Continued for all engines

l  Engine runs in idling speed l  for engine with engine identification characters ARZ: Control unit in function 08 “read measured value block”
System in basic setting 33 →				⇐ Readout on display
xx.x %	x.xxx V
1	2	3	4	⇐ Display fields	Specification	Analysis
					---	---
					---	---
		Lambda probe voltage lambda probe before catalyst			0.000...1.000 V → Note 1.4...1.6 V	→ Anchor
	Lambda controller upstream of catalytic converter				-10,0...10,0 %	→ Anchor

3)  Valid for engine with engine identification characters ARZ   Note t  Re display field 1: t  In the range between -10.0...10.0% the value must oscillate around minimum 2%.   Note t  For engine with engine identification characters ARZ re display field 1: t  Readout must fluctuate around zero. If zero is always displayed, the lambda control has switched from closed-loop to open-loop control because of a fault in the lambda control. Interrogate the fault memory → Chapter.   Note t  For engine with engine identification characters ARX and AUM re display field 2: t  Display 1,500 V equals approx. Lambda 1. t  Voltage signal “Mixture rich” (low level of residual oxygen) is between approx. 0.130...1.500 V. t  Voltage signal “Mixture lean” (high level of residual oxygen) is at approx. 1.500...4.800 V.   Note t  For engine with engine identification characters ARZ re display field 2: t  Voltage signal “Mixture rich” (low level of residual oxygen) is between approx. 0.7...1.0 V. t  Voltage signal “Mixture lean” (high level of residual oxygen) is at approx. 0.0...0.3 V. t  A voltage jump from 0.7...1.0 V to 0.0...0.3 V or vice versa takes place at the transition from “rich” to “lean” and vice versa (λ = 1.0). t  In view of the steep voltage jump the lambda control is not able to maintain constant the ideal mixture composition which corresponds to λ = 1.0. The control constantly fluctuates back and forward between the “slightly too lean” and “slightly too rich” states. In the range 0.00...1.00 V the voltage must oscillate approx. 20 times per minute. t  If the specified values are not reached: Conduct a test drive in order to eliminate any residues on the lambda probe and repeat the test.

Voltage of the 4-pin lambda probe in U λ in mV A: Lambda probe voltage high t  rich mixture (fuel surplus or air shortage) t  high CO value B: Lambda probe voltage low t  lean mixture (fuel shortage or air surplus) t  low CO value Analysis of display group 033, display field 1 - lambda control - probe before catalyst

Display -V.A.G 1552 -	Possible cause of fault	Rectifying fault
outside the tolerance range	t  Minimum range: Engine too rich, lambda control leans off t  Plus range: Engine too lean, lambda control enriches t  Unmetered air t  Injection valve defective t  Lambda learned values on limit	–  wait 30 seconds until the display has stabilised –  Inspect intake system for leaks → Chapter –  Testing injection rate → Chapter –  Test lambda initialisation values in display group 032

Analysis of display group 033 for engine with engine identification characters ARZ, display field 2 - lambda probe voltage before catalyst

Display -V.A.G 1552 -	Possible cause of fault	Rectifying fault
constant 1.100 V	t  Short-circuit to positive terminal in: Lambda probe, lambda probe cable, earth lead, engine control unit	–  Test lambda probe wire
constant 0.400 to 0.500 V	t  Line interruption in: Lambda probe, lambda probe cable, earth lead, engine control unit
constant 0.000 V	t  Short-circuit to earth in: Lambda probe, lambda probe cable, engine control unit

Note t  Re display field 2: t  Voltage signal is generated and smoothened by the engine control unit. Analysis of display group 033, display field 2 - lambda probe voltage upstream of catalytic converter

Display -V.A.G 1552 -	Possible cause of fault	Rectifying fault
greater than 4.800 V	t  Line short-circuit to earth in the line from the engine control unit to the lambda probe t  Lambda probe defective	–  Check lambda probe wire upstream of catalytic converter –  Replace lambda probe before catalytic converter.
less than 0.130 V	t  Line short-circuit to earth in the line from the engine control unit to the lambda probe t  Lambda probe defective

Display group 034, lambda control - diagnosis of lambda probe ageing For engine with engine identification characters ARX and AUM

l  Vehicle stationary, engine running at fast idling l  Control unit in function 04 “Initiate basic setting”
System in basic setting 34 →				⇐ Readout on display
xxxx rpm	xxx.x °C	x.xx	Text
1	2	3	4	⇐ Display fields	Specification	Analysis
				Result of test of lambda probe ageing upstream of catalytic converter (Test OFF /Test ON/B1 -S1- O.K./B1 -S1- n.o.k.)	B1-S1- OK.	---
			Period of lambda probe upstream of catalytic converter		0,50...2,50	---
		Exhaust gas temperature			greater than 350 °C	---
	Engine speed				2000 rpm	---

Note t  Re display field 2: t  Value determined by engine speed and engine load.   Note t  Regarding display fields 3 and 4: t  The period indicates the time between two jumps (e.g. rich - lean - rich mixture) and is thus a measure of the lambda probe ageing. If the prescribed time is exceeded, the display in display field 4 = B1-S1- N.O.K.. Display group 036, lambda control - operation downstream of catalytic converter

l  Vehicle standing, engine running at high speed l  Control unit in function 04 “Initiate basic setting”
System in basic setting 36 →				⇐ Readout on display
x.xxx V	Text
1	2	3	4	⇐ Display fields	Specification	Analysis
					---	---
					---	---
		Test lambda probe downstream of catalytic converter (Test OFF/Test ON/B1 -S2- O.K./B1 - S2- n.o.k.)			B1-S2- OK.	---
	Lambda probe voltage after catalytic converter				0.000...1.000 V	→ Anchor

Note If the specified values are not reached: Conduct a test drive in order to eliminate any residues on the lambda probe and repeat the test.   Note t  Re display field 1: t  Voltage signal “Mixture rich (low level of residual oxygen)” is at approx. 0.700...0.900 V. t  Voltage signal “Mixture lean (high level of residual oxygen)” is at approx. 0.000...0.300 V. t  A voltage jump from 0.700...0.900 V to 0.000...0.300 V or vice versa takes place at the transition from “rich” to “lean” and vice versa (λ = 1.0). t  In view of the steep voltage jump the lambda control is not able to maintain constant the ideal mixture composition which corresponds to λ = 1.0. The control constantly fluctuates back and forward between the “slightly too lean” and “slightly too rich” states.

Voltage of the 4-pin lambda probe in U λ in mV A: Lambda probe voltage high t  rich mixture (fuel surplus or air shortage) t  high CO value B: Lambda probe voltage low t  lean mixture (fuel shortage or air surplus) t  low CO value Analysis of display group 036, display field 1 - lambda probe voltage, lambda probe downstream of catalytic converter

Display field: 1	Possible cause of fault	Rectifying fault
constant 1.085 V	t  Short-circuit to positive terminal in: Lambda probe, lambda probe cable, earth lead, engine control unit	–  Test basic voltage of the lambda probe downstream of catalytic converter → Chapter –  Wiring to lambda probe downstream of catalytic converter
constant 0.400...0.500 V	t  Line interruption in: Lambda probe, lambda probe cable, earth lead, engine control unit
constant 0.000 V	t  Short-circuit to earth in: Lambda probe, lambda probe cable, engine control unit

Display group 037, diagnosis of lambda control system For engine with engine identification characters ARX and AUM

l  Vehicle standing, engine running at high speed l  Control unit in function 04 “Initiate basic setting”
System in basic setting 37 →				⇐ Readout on display
xx.x %	x.xxx V	x.xxx	Text
1	2	3	4	⇐ Display fields	Specification	Analysis
				Test lambda probe (Test ON / Test OFF, Syst. o.k. / Syst. n.o.k.)	Syst. o.k.	---
			Correction value between lambda probe upstream and downstream of catalytic converter		less than 0.02	---
		Lambda probe voltage after catalytic converter			0.000...1.000 V	→ Anchor
	Engine load				13,0...40,0 %

Note t  When testing maintain the engine speed at approx. 2000 rpm. t  If the specified values are not reached: Conduct a test drive in order to eliminate any residues on the lambda probe and repeat the test. t  If the lambda probe voltage is O.K. after a test drive and if the correction value between lambda probe upstream and downstream of the catalytic converter is above value 0.02 this means that the lambda probe upstream of the catalytic converter has aged.   Note t  Re display field 2: t  Lambda probe voltage downstream of catalytic converter may remain constant. Analysis of display group 037, display field 2

Display -V.A.G 1552 -	Possible cause of fault	Rectifying fault
constant 0.450 V	t  Line interruption in the line 4 from the engine control unit to the lambda probe	–  Test basic voltage → Chapter
	t  Line interruption in the line 3 from the engine control unit to the lambda probe
greater than 0.950 V	t  Short-circuit to positive in the line 4 from the engine control unit to the lambda probe	–  Wiring to lambda probe downstream of catalytic converter
less than 0.100 V	t  Short-circuit to earth in the line 4 from the engine control unit to the lambda probe

Display group 041, lambda control (resistance of lambda probe heater) Continued for all engines

Read measured value block 41 →				⇐ Readout on display
	Text		Text
1	2	3	4	⇐ Display fields	Specification	Analysis
				Lambda probe heating downstream of catalytic converter	Htg dC.OFF Htg dC.ON	---
						---
		Lambda probe heating upstream of catalytic converter			Htg.uC.OFF Htg.uC.ON	---
						---

Note Depending on the operating state of the engine the lambda probe heaters are switched on or off, i.e. the readouts in display field 2 and 4 may show either Htg.u(d)C.ON or Htg.u(d)C.OFF. Display group 043, diagnosis lambda probe ageing downstream of catalytic converter For engine with engine identification characters ARX and AUM

l  Vehicle standing, engine running at high speed l  Control unit in function 04 “Initiate basic setting”
System in basic setting 43 →				⇐ Readout on display
xxxx rpm	xxx.x °C	x.xxx V	Text
1	2	3	4	⇐ Display fields	Specification	Analysis
				Test lambda probe (Test OFF / Test ON, B1 -S2 - O.K. / B1-S2- n.o.k.)	B1-S2- OK.	---
			Lambda probe voltage after catalytic converter		0.000...1.000 V	---
		Catalytic converter temperature			greater than 350 °C	---
	Engine speed				2000 rpm	---

Display group 046, lambda control - diagnosis of catalytic converter For engine with engine identification characters ARX and AUM

l  Vehicle standing, engine running at high speed l  Control unit in function 04 “Initiate basic setting”
System in basic setting 46 →				⇐ Readout on display
xxxx rpm	xxx.x °C	x.xx	Text
1	2	3	4	⇐ Display fields	Specification	Analysis
				Test result of catalytic conversion (Test OFF / Test ON / Cat B1 o.k. / Cat B1 n.o.k.)	Cat B1 o.k.	---
			Learned stage counter		more than 1	---
		Catalytic converter temperature			min. 440.0°C	---
	Engine speed				2000 rpm	---

Display group 099, Lambda control For engine with engine identification characters ARZ

Read measured value block 99 →				⇐ Readout on display
xxxx rpm	xxx °C	xx %	Text
1	2	3	4	⇐ Display fields	Specification	Analysis
				Lambda control: ON/OFF basic setting 04: Reg.λ OFF read measured value block 08: Reg.λ ON	reg.λ OFF reg.λ ON	---
			Lambda regulator		-10...+10%	---
		Coolant temperature			80...100 °C	---
	Engine speed				640...820 rpm	---

Note t  To display group 099: t  For defined fault finding the lambda control is switched off when selected in display group 099 in function 04 “Initiate basic setting” and switched on in function 08 “Read measured value block”. t  It can be switched back and forward between the function 04 “Basic setting” and the function 08 “Read measured value block” by pressing the keys 4 and 8 at -V.A.G 1552-.