Skoda Workshop Service and Repair Manuals

Reading measured value blocks, display groups from 030 to 126 Display group 030 in idle

Reading measured value block 30			→	< Readout on display
xxx	xxx
1	2	3	4	< Display field	Specification	Analysis
				no display	---	---
			no display		---	---
		Status of lambda probe after catalytic converter and lamda control 1)			11X	→ Anchor
	Status of lambda probe before the catalytic converter and lambda control				111	→ Anchor

1) only engines with identification characters AQV, ATZ, AQW, AZF

Analysis: Display group 030, display field 1 and 2

Meaning, if display positions = 1
X	X	X	Operating position
1			Lambda probe heater active
	1		Lambda probe operational
		1	Lambda controller active

Display group 031 in idle for engines with identification characters ARV, AME, AZE

Reading measured value block 31			→	< Readout on display
x.xx V	x.xx V
1	2	3	4	< Display field	Specification	Analysis
				no display	---	---
			no display		---	---
		Disregard display			---	---
	Lambda probe voltage before catalyst				0.00…1.00 V	→ Anchor

Note t  Re display field 2: t  Voltage signal “Mixture rich (low level of residual oxygen)” is at 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. t  The readout must in some cases be less than 0.3 V and in some cases more than 0.6 V. The readout below 0.45 V indicates a lean mixture while above 0.45 V indicates a rich mixture. t  At idling speed, the lambda probe voltage upstream of the catalytic converter must fluctuate between a rich and leaner mixture. The lambda probe voltage downstream of the catalytic converter should indicate a constant rich or lean mixture. If the voltage also fluctuates downstream of the catalytic converter, either the catalytic converter is faulty ( ⇒ Read measured value block 046 → Anchor) or the probes have been wrongly connected (irregular engine running). Lambda control varies between -15...15 %.

Voltage of the 4-pin lambda probe in U λ in mV A: Lambda probe voltage high rich mixture (fuel surplus or air shortage) high CO value B: Lambda probe voltage low lean mixture (fuel shortage or air surplus) low CO value Analysis: Analysis of display group 031, display field 1 - lambda probe voltage upstream of catalytic converter

Display field 1	Possible cause of fault	Rectifying fault
constant 0.00...0.30 V or constant 0.70...1.00 V	t  large volume of unmetered air t  Spark plug defective t  Injection valve defective t  Coolant temperature sender -G62- faulty t  Activated charcoal filter solenoid valve defective t  Lambda probe heater before catalyst not operational t  Lambda probe before catalyst defective/dirty	–  Testing the intake system for tightness (unmetered air) → Chapter. –  Inspect spark plugs –  Testing injection valves → Chapter. –  Coolant temperature sender -G62- → Chapter. –  Inspect tank ventilation → Chapter. –  Testing lambda probe and lambda control upstream of catalytic converter → Chapter.
constant 1.00 V	Short-circuit to positive terminal in: t  Lambda probe before catalyst t  Lambda probe wire t  Earth lead t  Engine control unit	–  Testing lambda probe and lambda control upstream of catalytic converter → Chapter.
between 0.40...0.50 V	Line interruption in: t  Lambda probe before catalyst t  Lambda probe wire t  Earth lead t  Engine control unit
constant 0.00 V	Short-circuit to earth in: t  Lambda probe before catalyst t  Lambda probe wire t  Engine control unit

Display group 031, lambda values upstream of catalytic converter in idle for engines with identification characters AQV, ATZ, AQW, AZF

Reading measured value block 31			→	< Readout on display
x.xxxx	x.xxxx
1	2	3	4	< Display field	Specification	Analysis
				no display	---	---
			no display		---	---
		Lambda nominal value Bank 1			0,9900…1,0100	---
	Lambda actual value Bank 1				0,9600…1,0400	---

Display group 032 - Lambda control, Lambda initialisation values in idle

Read measured value block 32 →				⇐ Read out on display:
xx.x %	xx.x %	—	—
1	2	3	4	⇐ Display field	Specification	Analysis:
					—	—
					—	—
		Lambda learned value under partial load (multiplicative) upstream of catalytic converter			-10,0...10,0 %	→ Anchor
	Lambda learned value in idling (additive) upstream of catalytic converter				-10,0...10,0 %	→ Anchor

Note t  Re 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  Initialisation conditions for partial load. Coolant temperature at least 75 °C, intake air temperature max. 90 °C, normal driving Analysis of display group 032, Lambda control, Lambda learned values

Display field	Readout on display:	Possible cause of fault	Rectifying fault
1 and 2	low lambda learned values	t  Low learned values in idling at normal learned values in partial load: Oil dilution (higher fuel content in the oil) possible	–  Disappears after driving on motorway or changing oil.
		t  Injection valve leaks	–  Testing injection valves → Chapter.
		t  Fuel pressure too high	–  Test fuel pressure regulator and holding pressure → Chapter.
		t  Solenoid valve 1 for activated charcoal filter -N80- constantly open	–  Testing activated charcoal filter system solenoid valve 1 → Chapter.
		t  Lambda probe heating defective or lambda probe dirty	–  Test lambda probe heating before catalyst → Chapter.

Display field	Readout on display:	Possible cause of fault	Rectifying fault
1 and 2	high lambda initialisation values	t  High learned values in idling at less high learned values in partial load: Unmetered air in intake manifold region possible	–  Test intake system for leaks → Chapter.
		t  Unmetered air between air filter and throttle valve	–  Eliminate cause.
		t  Unmetered air at the exhaust manifold gasket	–  Eliminate cause.
		t  Injection valve blocked	–  Testing injection valves → Chapter.
		t  Fuel pressure too low	–  Test fuel pressure regulator and holding pressure → Chapter.
		t  Lambda probe heating defective or lambda probe dirty	–  Test lambda probe heating before catalyst → Chapter.

Display group 033, lambda control and lambda probe voltage upstream of catalytic converter in idle for engines with identification characters AQV, ATZ, AQW, AZF

Reading measured value block 33			→	< Readout on display
xx.x %	x.xxx V
1	2	3	4	< Display field	Specification	Analysis
				no display	---	---
			no display		---	---
		Lambda probe voltage before catalyst			1,40 ... 1,60 V	→ Anchor
	Lambda regulator upstream of catalytic converter				-10,0…10,0 %	→ Anchor

Lambda probe voltage upstream of catalytic converter in idle for engines with identification characters AQV, ATZ, AQW, AZF   Note t  Re display field 2: t  Display 1.50 V equals approx. Lambda 1. t  Voltage signal “Mixture rich” (low level of residual oxygen) is at approx. 0.13...1.50 V. t  Voltage signal “Mixture rich” (high level of residual oxygen) is at approx. 1.50...4.80 V. t  Lambda probe enables through its structure constant lambda control due to the permanent signal for the deviation of λ = 1. t  The control is performed dynamic, as the deviation from the specification is current and is known as the concrete value. Display group 034, diagnosis of lambda probe upstream of catalytic converter for engines with identification characters AQV, ATZ, AQW, AZF (ageing test) l  Diagnostic device in function 04 “basic setting” l  Actuate brake pedal, engine running at high idling speed

System in basic setting 34			→	< Readout on display
xxxx rpm	xxxx °C	x.xxx	Text
1	2	3	4	< Display field	Specification	Analysis
				Result of ageing test of the lambda probe before catalyst (Test OFF / Test ON / B1 S1 O.K. / B1 S1 N.O.K.)	B1-S1 o.k.	---
			Disregard display		-	---
		Catalytic converter temperature			min. 400 °C	---
	Engine speed 1.0 ltr. engine 1.4 ltr. engine				1100 …1700 rpm	---

Display group 036 - lambda control, diagnosis of lambda probe downstream of catalytic converter for engines with identification characters AQV, ATZ, AQW, AZF l  Diagnostic device in function 04 “basic setting” l  Actuate brake pedal, engine running at high idling speed

System in basic setting 36 →				⇐ Read out on display:
x.xxx V	Text	—	—
1	2	3	4	⇐ Display field	Specification	Analysis:
					—	—
					—	—
		Test lambda probe downstream of catalytic converter (Test OFF/Test ON/ B1 S2 o.k. / B1 S2 n.o.k.)			B1 S2 o.k.	—
	Lambda probe voltage after catalytic converter				0.000...1.000 V	→ Anchor

Analysis of display group 036, lambda probe voltage, lambda probe downstream of catalytic converter

Display field	Readout on display:	Possible cause of fault	Rectifying fault
1	constant 1,100 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 –  Check lambda probe wire downstream of catalytic converter → Chapter
	constant between 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, earth lead, engine control unit

Display group 037 - Lambda control, Lambda probes downstream of catalytic converter l  Diagnostic device in function 04 “basic setting” l  Actuate brake pedal, engine running at high idling speed

System in basic setting 37 →				⇐ Read out on display:
xx.x %	x.xxx V	x.x %	Text
1	2	3	4	⇐ Display field	Specification	Analysis:
				Test lambda probes (Test ON / Test OFF / Syst. O.K. / Syst. N.O.K.)	B1-S1 o.k.	—
			Ignore		—	—
		Lambda probe voltage after catalytic converter			0.000...1.000 V	→ Anchor
	Engine load				12,0...40,0 %	—

Note t  Re display field 2: t  Voltage signal “Mixture rich (low level of residual oxygen)” is at 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. t  The readout must in some cases be less than 0.3 V and in some cases more than 0.6 V. The readout below 0.45 V indicates a lean mixture while above 0.45 V indicates a rich mixture. t  At idling speed, the voltage of the lambda probe upstream of the catalytic converter -G39- must fluctuate between a rich and leaner mixture. The voltage of the lambda probe downstream of the catalytic converter -G130- should indicate a constant rich or lean mixture. If the voltage also fluctuates downstream of the catalytic converter, either the catalytic converter is faulty (Read measured value block 046 ) or the probes have been wrongly connected (irregular engine running). Lambda control varies between -15...15 %. Display group 041 in idle - lambda control, lambda probe heating

Read measured value block 41 →				⇐ Read out on display:
—	Text	xxx ohms	Text
1	2	3	4	⇐ Display field	Specification	Analysis:
				Lambda probe heating downstream of catalytic converter	Ht. after c. ON Ht. after c. OFF	—
			Resistance lambda probe heating downstream of catalytic converter		—	—
		Lambda probe heating upstream of catalytic converter			Ht. bf. c. ON Ht. bf. c. OFF	—
					—	—

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 of lambda probe downstream of catalytic converter for engines with identification characters AQV, ATZ, AQW, AZF (ageing test) l  Diagnostic device in function 04 “basic setting” l  Actuate brake pedal, engine running at high idling speed

System in basic setting 43			→	< Readout on display
xxxx rpm	xxxx °C	x.xx V	Text
1	2	3	4	< Display field	Specification	Analysis
				Result of ageing test of the lambda probe after catalyst (Test OFF / Test ON / B1-S2 O.K. / B1-S2 N.O.K.)	B1-S2 o.k.	---
			Lambda probe voltage after catalytic converter		0.00 bis 1.00 V	→ Anchor
		Catalytic converter temperature			min. 400 °C	---
	Engine speed 1.0 ltr. engine 1.4 ltr. engine				1100 …1700 rpm	---

Display group 046, diagnosis of catalyst efficiency for engines with identification characters AQV, ATZ, AQW, AZF l  Diagnostic device in function 04 “basic setting” l  Actuate brake pedal, engine running at high idling speed

System in basic setting 46			→	< Readout on display
xxxx rpm	xxxx °C	x.xx	Text
1	2	3	4	< Display field	Specification	Analysis
				Result of catalyst inspection (TEST OFF/TEST ON/Cat. B1 O.K./Cat. B1 N.O.K.)	Cat B1 o.k.	---
			Catalyst efficiency		0,50...1,00	---
		Catalytic converter temperature			min. 400 °C	---
	Engine speed 1.0 ltr. engine 1.4 ltr. engine				1100 …1700 rpm	---

Display group 099 in idle - Lambda control, Operating condition of lambda control: l  Engine idling

Read measured value block 99 →				⇐ Read out on display:
xxxx rpm	xxx °C	xx.x %	Text
1	2	3	4	⇐ Display field	Specification	Analysis:
				Operating condition of lambda control	OFF ON	—
			Lambda control before catalyst		-10,0…10,0 %	→ Anchor
		Coolant temperature			80...115 °C	—
	Engine speed (idling speed) 1.0 ltr. engine 1.4 ltr. engine				630...770 rpm 730...870 rpm	—

Display group 050, engine idling

Reading measured value block 50			→	< Readout on display
xxx rpm	xxx rpm	Text	Text
1	2	3	4	< Display field	Specification	Analysis
				Air conditioning compressor on, off	Compr. OFF	---
			Disregard display		---	---
		Engine speed (idling speed nominal value) 1.0 ltr. engine 1.4 ltr. engine			700 rpm 800 rpm	---
	Engine speed (idling speed) 1.0 ltr. engine 1.4 ltr. engine				630...770 rpm 730...870 rpm	---

Display group 054 in idle

Reading measured value block 54			→	< Readout on display
xxx rpm	Text	xx.x %	x.x %
1	2	3	4	< Display field	Specification	Analysis
				Disregard display	---	---
			Sender 1 for accelerator pedal position		10,0...20,0 %	---
		Operating condition (idling, enrichment, partial load, full load, overrun fuel cut-off)			Idling	---
	Engine speed (idling speed) 1.0 ltr. engine 1.4 ltr. engine				630...770 rpm 730...870 rpm	---

Display group 055 in idle - Speed control, idle stabilizer

Read measured value block 55 →				⇐ Read out on display:
xxxx rpm	xx Nm	xx.x %	xxxxx
1	2	3	4	⇐ Display field	Specification	Analysis:
				Operating conditions	xxxxx	→ Anchor
			Initialisation value idling control
				Air conditioning on	-6,0...8,0 %	—
				Air conditioning off	-3,0...8,0 %
		Idling control			5,0...40,0 %	—
	Engine speed (idling speed) 1.0 ltr. engine 1.4 ltr. engine				630...770 rpm 730...870 rpm	---

Note t  Re display field 3: t  The display shows to what extent the idling stabilizer has “disinitialised” from the constructively given mean value. On a new engine the value is in the positive region because of the higher friction, on a run-in engine it is in the negative region. Display field 4 - Operating conditions, meaning of the digits in the 5-digit number block

Meaning if display positions = 1
1	2	3	4	5	Meaning
				1	Air conditioning compressor on
			x		No meaning
		1			Air conditioning switched on
	x				No meaning
x					No meaning

Display group 062 - checking the sender for the accelerator pedal position and the throttle valve angle l  Ignition on, engine stopped

Read measured value block 62 →				< Readout on display
xx.x %	xx.x %	xx.x %	xx.x %
1	2	3	4	< Display field	Specification		Analysis
					Do not actuate pedal	Actuate pedal
				Accelerator pedal position sender 2 -G185-	3…10 %	35,0…50,0 %	---
			Accelerator pedal position sender 1 -G79-		6…20 %	67,0…97,0 %	---
		Throttle valve angle ( throttle valve drive angle sender 2 for electric power control - G188- )			82,0…97,0 %	3,0…16,0 %	---
	Throttle valve angle ( throttle valve drive angle sender 1 for electric power control -G187- )				3,0…16,0 %	82,0…93,0 %	---

Notes on display group 062:

t	The potentiometers (throttle valve drive angle sender 2 for electric power control) of the throttle valve control unit and of the accelerator pedal position sender are duplicated for safety reasons. The engine control unit permanently inspects the correctness of the potentiometer.

t	The value of accelerator pedal position sender 2 -G185- must always be half of the value of accelerator pedal position sender 2 - G79-.

t	The potentiometers of the throttle valve control unit contra-rotate. The value of both potentiometers together must always be approx. 100%.

t	The specifications stated above are not fully utilised.

Display group 066, cruise control system (only on vehicles with cruise control system)

Reading measured value block 66			→	< Readout on display
xxx km/h	xxxx	xxx km/h	xxxx
1	2	3	4	< Display field	Specification	Analysis
				Switch position on the actuating lever of the CCS 1)	0000 0000
			Driving speed (nominal); last value stored by the CCS		x km/h	---
		Switch position of brake, clutch and CCS			0000 or 00000000
	Driving speed (actual)				xxx km/h	---

1) The 8-digit number block must not be shown on all vehicles.

Analysis: Display group 066, display field 2 - switch for brake, clutch and CCS

0000	X	X	X	X	Meaning, if display positions = 1
	1				Cruise control system deactivated
		1			Clutch depressed
			1		Brake pressed (brake pedal switch)
				1	Brake pressed (brake light switch)

Analysis: Display group 066, display field 4 - switch position of CCS

0000	X	X	X	X	Meaning
	0	0	0	0	Switch -B- locked to “OFF”
	0	0	0	1	Switch -B- to “OFF” before operating point
	0	0	1	1	Switch -B- to “ON”
	1	0	1	1	Switch -B- to “RES”
	0	1	1	1	Switch -A- pressed (switch -B- to “ON”)

Display group 070 - Activated charcoal filter system diagnosis (tank ventilation system) l  Engine idling l  Diagnostic device in function 04 “basic setting”

System in basic setting 70 →				⇐ Read out on display:
x.x %	x.x %	x.x %	Text
1	2	3	4	⇐ Display field	Specification	Analysis:
				Result of the activated charcoal filter system diagnosis (Test OFF/ Test ON/ TVV O.K./ TVV N.O.K.)	TVV o.k.	—
			Idling speed controller variation during TVV diagnosis		-5,0…5,0 %	—
		Lambda controller variation during TVV diagnosis			-15,0…15,0 %	—
	TVV control -N80-				0,0…100 %	—

Note TVV means Tank Vent Valve (activated charcoal filter solenoid valve 1). Display group 100 - readiness code l  Engine idling

Read measured value block 100 →				⇐ Read out on display:
xxxxxxxx	xxx.x °C	xxx s	xxxxxxxx
1	2	3	4	⇐ Display field	Specification	Analysis:
				Diagnosis status	—	—
			Time since engine start		—	—
		Coolant temperature			80.0...110.0 °C	→ Chapter 01-5
	Readiness code				00000000

Display field 1 - Readiness code - Meaning of the digits in the 8-digit numerical block

The readiness code is only generated if all the display positions show 0
1	2	3	4	5	6	7	8	Diagnosis function
							0	Catalytic converter
						0		Catalytic converter heating (no diagnosis at present/always “0”)
					0			Activated charcoal filter system (tank ventilation system)
				0				Secondary air injection system (not fitted/always “0”)
			0					Air conditioning system (currently no diagnosis/always “0”)
		0						Lambda probes
	0							Lambda probe heater
0								Exhaust gas recirculation

Display group 120 - traction control system (TCS) l  Driving

Read measured value block 120 →				⇐ Read out on display:
xxxx rpm	xxx Nm	xxx Nm	Text
1	2	3	4	⇐ Display field	Specification	Analysis:
				Status	TCS active / TCS inactive	—
			Actual engine load		—	—
		Nominal engine load			—	—
	Engine speed				xxxx rpm	—

Display group 125 - communication, databus messages l  Engine idling

Read measured value block 125 →				⇐ Read out on display:
Text	Text	Text	Text
1	2	3	4	⇐ Display field	Specification	Analysis:
				Status airbag	Airbag 1
			Status of combiinstrument		Combi 1
		---			---	—
	Status ABS				ABS 1

Display group 126 - communication, databus messages l  Engine idling

Read measured value block 126 →				⇐ Read out on display:
Text	Text	Text	Text
1	2	3	4	⇐ Display field	Specification	Analysis:
				---	---	—
			---		---	—
		Status of the vehicle voltage control unit			El. CU 1
	Status of the air-conditioning system				Clima 1

Note t  To the display groups 125 and 126: t  Nominal value = 1; the control units with active data bus are displayed.

Display -V.A.G 1552-	Possible cause of fault	Rectifying fault
if 0 displayed instead of 1	t  CAN databus connection defective	–  Checking the data BUS CAN databus → Chapter –  Perform the automatic test sequence for interrogation of all fault memories.
	t  CAN databus cables defective - control unit