Skoda Workshop Service and Repair Manuals

Reading measured value blocks, display groups 001 to 029 Display group 001 - Basic functions

l  Engine idling
Read measured value block 1 →				← Readout on display
xxxx rpm	xx.x °C	xx.x %	xxxxxx
1	2	3	4	← Display fields	Specification	Analysis
				Operating conditions	11111111	→ Anchor
			Lambda regulator upstream of catalytic converter		-10,0...10,0 %	→ Anchor
		Coolant temperature			80.0 ...110.0 °C	→ Anchor
	Engine speed (idling speed)				680...880 rpm	→ Anchor

Note t  Re display field 3: 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. Analysis of display group 001, display field 1 - engine speed (idling speed)

Readout on -V.A.G 1552 -	Rectifying fault
less than 680 rpm	–  Testing throttle valve control unit → Chapter
	–  Inspect intake system for leaks
greater than 880 rpm	–  Interrogating fault memory → Chapter
	–  Inspect intake system for leaks
	–  Testing throttle valve control unit → Chapter

Analysis of display group 001, display field 2 - coolant temperature

Readout on -V.A.G 1552 -	Rectifying fault
less than 80 °C	–  Conduct test drive if necessary
	–  Test resistance of coolant temperature sender → Chapter
greater than 110 °C	–  Clean radiator
	–  Test function of the radiator fan
	–  Test coolant thermostat, replace if necessary → 2.0/85 kW Engine, Mechanical Components; Rep. Gr.19
	–  Test resistance of coolant temperature sender → Chapter

Analysis of display group 001, display field 3 - lambda controller upstream of catalytic converter

Readout on -V.A.G 1552 -	Rectifying fault
Signal outside tolerance	–  Wait 30 seconds until readout has stabilised
	–  Inspect intake system for leaks
	–  Testing injection valves → Chapter, actuator diagnosis
	–  Test lambda initialisation values in display group 032 → Chapter

Analysis of display group 001, display field 4 - operating states

1	2	3	4	5	6	7	8	Meaning, if display positions = 1
							1	Coolant temperature more than 80°C
						1		Speed below 2000 rpm
					1			Throttle valve closed
				1				Lambda control o.k.
			1					Operating state - idling
		1						AC compressor disconnected
	1							No meaning
1								No fault detected in self-diagnosis

Display group 002 - basic functions - air mass meter

l  Engine idling
Read measured value block 2 →				← Readout on display
xxxx rpm	xxx %	x.xx ms	x.x g/s
1	2	3	4	← Display fields	Specification	Analysis
				Drawn in air mass	2,0...5.0 g/s	→ Anchor
			Injection period		2.00...5.50 ms	→ Anchor
		Engine load			15...35 %	→ Anchor
	Engine speed (idling speed)				680...880 rpm	→ Anchor

Note t  Re display field 4: t  What is displayed is the inducted air mass which is determined by the air mass meter. t  If a fault is detected at the air mass meter by the engine control unit, the substitute value of the throttle valve potentiometer in g/s is displayed. t  In the emergency mode resulting from a fault at the throttle valve control unit, the engine runs without idling speed stabilisation at a higher idling speed which is dependent on the throttle valve position in an emergency mode position (approx. 1100...1500 rpm). Drawn in air mass approx. 4.5...5.5 g/s. Analysis of display group 002, display field 2 - engine load

Readout on -V.A.G 1552 -	Rectifying fault
less than 15 %	–  Testing throttle valve control unit → Chapter
greater than 35 %	–  Testing injection valves → Chapter, actuator diagnosis –  If necessary, replace spark plugs –  Disconnect electric consumer –  Testing throttle valve control unit → Chapter

Note t  The maximum engine load decreases approximately 10 % for each 1000 m above mean sea level. t  The maximum engine load decreases by up to 10 % at high temperatures. t  The following readouts must be reached when driving at full throttle: at 4000 rpm approx. 78 %, at 6000 rpm approx. 75 %. Analysis of display group 002, display field 3 - injection time

Readout on -V.A.G 1552 -	Rectifying fault
less than 2.00 ms	–  Test drive without full load for at least 10 minutes –  Testing solenoid valve for activated charcoal filter → Chapter, actuator diagnosis –  Testing injection valves → Chapter –  Iinspect fuel pressure regulator → Chapter
greater than 5.50 ms	–  Eliminate increased load (air conditioning, power steering etc.)

Analysis of display group 002, display field 4 - inducted air mass

Readout on -V.A.G 1552 -	Rectifying fault
less than 2.0 g/s	–  Inspect intake system for leaks
greater than 5.0 g/s	–  Eliminate load (AC, el. components switched on, etc.)

Display group 003 - basic functions - air mass meter

l  Engine idling
Read measured value block 3 →				← Readout on display
xxxx rpm	x.x g/s	x.x %	xx.x ° BTDC
1	2	3	4	← Display fields	Specification	Analysis
				Ignition angle	0...12.0 °BTDC	—
			Throttle valve angle		0,2...5,0 %	→ Anchor
		Drawn in air mass			2.0...5.0 g/s	→ Anchor
	Engine speed (idling speed)				680...880 rpm	→ Anchor

Analysis of display group 003, display field 3 - throttle valve angle

Readout on -V.A.G 1552 -	Rectifying fault
greater than 5.0 %	–  Adapt engine control unit to throttle valve control unit → Chapter. –  Interrogating fault memory → Chapter
	–  Testing throttle valve control unit → Chapter

Note Readout when accelerator pedal fully depressed is (90...100 %). Display group 004 - Basic functions

l  Engine idling
Read measured value block 4 →				← Readout on display
xxxx rpm	xx.xxx V	xxx.x °C	xxx.x °C
1	2	3	4	← Display fields	Specification	Analysis
				Intake manifold temperature	-45.0 ...140.0 °C	→ Anchor
			Coolant temperature		85.0 ...110.0 °C	→ Anchor
		Supply voltage of the engine control unit			12.500...14.500 V	→ Anchor
	Engine speed (idling speed)				680...880 rpm	→ Anchor

Note If a fault relating to the coolant temperature sender -G62- is stored in the fault memory, the engine control unit uses the intake air temperature as a substitute value (start temperature - substitute value) when the engine is started. The temperature then rises according to a model sequence stored in the control unit. Once the engine has reached normal operating temperature a fixed substitute value is displayed after a certain time. This fixed substitute value depends on the intake air temperature. The readout must be higher than the temperature of the ambient air. Analysis of display group 004, display field 2 - supply voltage to the engine control unit

Readout on -V.A.G 1552 -	Rectifying fault
less than 12.500 V	–  Test generator and battery voltage, charge battery → Electrical System; Rep. Gr.27
	–  Increase engine speed slightly for a few minutes and switch off additional consumers
	–  Test voltage supply of engine control unit → Chapter
	–  Eliminate current consumption
greater than 14.500 V	–  Test voltage, replace voltage regulator if necessary
	–  Interrogating fault memory → Chapter

Analysis of display group 004, display field 4 - intake air temperature

Readout on -V.A.G 1552 -	Rectifying fault
approx. 140,0 °C	–  Test resistance of intake air temperature sender -G42- → Chapter –  Test cables to intake air temperature sender -G42- → Current flow diagrams, Electrical fault finding and Fitting locations
approx. -46.5 °C
approx. 140 °C (readout appears only for a short time and then jumps to 19.5 °C)

Display group 005 - basic functions

l  Engine idling
Read measured value block 5 →				← Readout on display
xxxx rpm	xxx %	xxx km/h	Text
1	2	3	4	← Display fields	Specification	Analysis
				Operating state (idling, part load, full load, enrichment, overrun)	Idling	—
			Vehicle speed		0 km/h	—
		Engine load			10...35 %	→ Anchor
	Engine speed (idling speed)				680...880 rpm	→ Anchor

Note Testing the speed signal → Chapter. Display group 006 - Basic functions

l  Engine idling
Read measured value block 6 →				← Readout on display
xxxx rpm	xx.x %	xxx.x °C	x.x %
1	2	3	4	← Display fields	Specification	Analysis
				Level correction factor	—	—
			Intake manifold temperature		-45,0 ...140,0 °C	—
		Engine load			15,0...35,0 %	→ Anchor
	Engine speed (idling speed)				680...880 rpm	→ Anchor

Note t  Re display field 2: t  The maximum engine load decreases approximately 10 % for each 1000 m above mean sea level. t  The maximum engine load decreases by up to 10 % at high temperatures. t  The following readouts must be reached when driving at full throttle: at 4000 rpm approx. 78 %, at 6000 rpm approx. 75 %. Display group 010 ignition

l  Engine idling
Read measured value block 10 →				← Readout on display
xxxx rpm	xx.x %	x.x %	xx.x ° BTDC
1	2	3	4	← Display fields	Specification	Analysis
				Ignition angle	0...12 °BTDC	—
			Throttle valve angle		0,2...5,0 %	→ Anchor
		Engine load			15,0...35,0 %	→ Anchor
	Engine speed (idling speed)				680...880 rpm	→ Anchor

Display group 014 - ignition misfiring detection

l  Engine idling
Read measured value block 14 →				← Readout on display
xxxx rpm	xx.x %	xxx	Text
1	2	3	4	← Display fields	Specification	Analysis
				Status of misfiring detection (activated, deactivated)	activated	—
			Total of ignition misfirings		0...5	→ Anchor
		Engine load			15,0...35,0 %	→ Anchor
	Engine speed (idling speed)				680...880 rpm	→ Anchor

Display group 015 - ignition misfiring detection cylinders 1 to 3

l  Engine idling
Read measured value block 15 →				← Readout on display
xxx	xxx	xxx	Text
1	2	3	4	← Display fields	Specification	Analysis
				Status of misfiring detection (activated, deactivated)	activated	—
			Total of ignition misfirings cyl. 3		0	→ Anchor
		Total of ignition misfirings cyl. 2			0	→ Anchor
	Total of ignition misfirings cyl. 1				0	→ Anchor

Display group 016 - ignition misfiring detection cyl. 4

l  Engine idling
Read measured value block 16 →				← Readout on display
xxx	—	—	Text
1	2	3	4	← Display fields	Specification	Analysis
				Status of misfiring detection (activated, deactivated)	activated	—
					—	—
					—	—
	Total of ignition misfirings cyl. 4				0	→ Anchor

Analysis of display groups 014, 015, 016 - total of ignition misfiring cyl. 1 to 4

Readout on -V.A.G 1552 -	Rectifying fault
greater than 5	–  Test ignition transformer → Chapter –  Test spark plugs and spark cables with spark plug connector –  Testing injection valves → Chapter –  Check fuel level in tank

Display group 022, ignition - knock control

l  Normal driving
Read measured value block 22 →				← Readout on display
xxxx rpm	xxx.x %	xx.x °CA	xx.x °CA
1	2	3	4	← Display fields	Specification	Analysis
				Ignition angle retarded in cylinder 2 by knock control	0...15.0 °CA	→ Anchor
			Ignition angle retarded in cylinder 1 by knock control		0...15.0 °CA	→ Anchor
		Engine load			0,0...100,0 %	—
	Engine speed				680...6500 rpm	—

Display group 023, ignition - knock control

l  Normal driving
Read measured value block 23 →				← Readout on display
xxxx rpm	xxx.x %	xx.x °CA	xx.x °CA
1	2	3	4	← Display fields	Specification	Analysis
				Ignition angle retarded in cylinder 4 by knock control	0...15.0 °CA	→ Anchor
			Ignition angle retarded in cylinder 3 by knock control		0...15.0 °CA	→ Anchor
		Engine load			0,0...100,0 %	—
	Engine speed				680...6500 rpm	—

Note t  Knock control active from an engine load of more than 40 %. t  If an engine load of 40 % is exceeded, the current retardation of the ignition angles are displayed. If the engine load was not reached, the values last used are displayed. t  If knocking can be heard without any retardation of the ignition angle detectable, increase engine speed for 5 seconds to more than 3500 rpm in order to activate the knock sensor fault detection (for self-diagnosis). Analysis of display groups 022/023, display fields 3 and 4 - ignition angle retardation

Readout on -V.A.G 1552 -	Rectifying fault
all cylinders greater than 15 °CA	–  Test knock sensors -G61- and -G66- –  Slacken knock sensor and tighten again to 20 Nm –  Tighten up loose parts –  Change type of fuel
one cylinder clearly deviates from the others	–  Test knock sensors -G61- and -G66- –  Testing compression: → 2.0/85 Engine, Mechanical Components; Rep. Gr.15 –  Tighten up loose parts

Display group 026, ignition - knock sensor

l  Normal driving
Read measured value block 26 →				← Readout on display
x.xxx V	x.xxx V	x.xxx V	x.xxx V
1	2	3	4	← Display fields	Specification	Analysis
				Knock sensor voltage signal cyl. 4	0.400...2.000 V	—
			Knock sensor voltage signal cyl. 3		0.400...2.000 V	—
		Knock sensor voltage signal cyl. 2			0.400...2.000 V	—
	Knock sensor voltage signal cyl. 1				0.400...2.000 V	—

Note t  If no fault is found when testing the knock sensor, the wiring and the plug connections, inspect the ancillaries or the engine for damage. t  At higher engine speeds the readout of the knock sensor voltage signal may be as much as 5.1 V. t  If a difference of more than 50 % exists between the smallest and largest knock sensor signal, the cause may be corrosion at the plug connection. Display group 028, ignition - testing knock sensor

l  Normal driving
Read measured value block 28 →				← Readout on display
xxxx rpm	xxx.x %	xxx.x °C	Text
1	2	3	4	← Display fields	Specification	Analysis
				Test Knock sensor (Test OFF, Test ON, Syst. o.k., Syst. n.o.k.)	Syst. o.k.	—
			Coolant temperature		80.0 ...100.0 °C	→ Anchor
		Engine load			20,0...100,0 %	—
	Engine speed				2500...6500 rpm	—