Skoda Workshop Service and Repair Manuals

List of display groups

Display group 000 (display values in decimals)
Test conditions l  Engine idling l  Coolant temperature minimum 80°C l  electrical consumers disconnected
Display fields											displayed specified value	corresponds to measured value
1	2	3	4	5	6	7	8	9	10	Engine speed	77 - 68	760 - 860 rpm
									Injection period		5 - 12	2.56 - 6.14 ms
								Throttle valve potentiometer voltage			24 - 50	4.53 - 4.02 V
							not assigned				0	0
						Lambda control correction factor					75 - 165	Standard value 128
					Lambda probe voltage						0 - 205	0 - 1 V
				Intake manifold pressure							45 - 88	300 - 500 mbar
			Coolant temperature								37 - 18	80 - 110 °C
		Battery voltage									186 - 226	12 - 14.5 V
	Intake manifold temperature										156 - 35	15 - 80 °C

Test table - Display group 000

Display field	Display -V.A.G 1552 -	Fault cause	Rectifying fault
1	less than 351)	t  Open circuit in wiring or line short-circuit to intake air temperature sender	–  Test cable to sender for open circuit and short-circuit
	greater than 1561)	t  Intake air temperature sender faulty	–  Test intake air temperature sender → Chapter
2	less than 186	t  AC generator defective, battery heavily discharged	–  Test voltage, recharge battery
		t  Vehicle voltage heavily loaded just after start by a high charge current or by auxiliary equipment	–  Increase engine speed slightly for a few minutes and switch off additional consumers
		t  Transition resistance in the positive power supply or earth connection for engine control unit	–  Check the supply voltage of the engine control unit → Chapter
		t  Current consumption with ignition off	–  Eliminate current consumption
	greater than 226	t  Voltage regulator on AC generator defective	–  Test voltage, replace regulator if necessary
		t  Overvoltage due to starting aid or quick charger	–  Interrogating fault memory → Chapter
3	less than 18	t  Coolant temperature sender or cable connection to engine control unit faulty	–  Test coolant temperature sender -G62- → Chapter
		t  Radiator dirty	–  Clean radiator
		t  Radiator fan not operational	–  Test function of the radiator fan
		t  Coolant regulator (thermostat) defective	–  Inspect coolant regulator (thermostat)
	greater than 37	t  Engine too cold	–  Warm up engine to operating temperature
		t  Coolant temperature sender or cable connection to engine control unit faulty	–  Test coolant temperature sender -G62- → Chapter
		t  Coolant regulator (thermostat) remains open	–  Inspect coolant regulator (thermostat)
4	Value outside the tolerance	t  Air filter dirty or air supply blocked	–  Replace air filter or unblock air supply
		t  Unmetered air	–  Eliminate unmetered air

1) Depending on the ambient temperature

Test table - Display group 000

Display field	Display -V.A.G 1552 -	Fault cause	Rectifying fault
5	Display does not fluctuate	t  large unmetered air volume	–  Eliminate unmetered air
		t  Spark plug defective	–  Inspect spark plugs
		t  Holding pressure too low or too high	–  Test fuel pressure regulator and holding pressure → Chapter
		t  Injection valve defective	–  Testing injection valves → Chapter
		t  Coolant temperature sender - G62- faulty	–  Test coolant temperature sender -G62- → Chapter
		t  Activated charcoal filter solenoid valve -N80- defective, blocked or jams	–  Testing solenoid valve for activated charcoal filter → Chapter.
		t  Lambda probe heater does not operate	–  Check lambda probe heater → Chapter
		t  Lambda probe defective or dirty	–  Interrogate fault memory → Chapter, if necessary check lambda probe → Chapter
	constant 255	t  Short circuit to positive through: Lambda probe or signal line or engine control unit	–  Checking lambda probe → Chapter
	constant 80	t  Line interruption through: lambda probe or signal line or engine control unit	–  Checking lambda probe → Chapter
	constant 0	t  Short circuit to earth through: Lambda probe or signal line or engine control unit	–  Checking lambda probe → Chapter
6	Ignore
8	less than 24	t  Basic setting of the throttle valve control unit not carried out	–  Perform basic setting of the throttle valve control unit → Chapter.
		t  Throttle valve potentiometer in the throttle valve control unit -J338- defective or incorrectly set	–  Inspecting throttle valve control unit -J338- → Chapter
		t  Incorrect throttle cable setting	–  Adjusting throttle control cable → 1.6 ltr./55 kW Engine, Mechanics; Rep. Gr.20
		t  Throttle valve jams	–  Adjusting throttle control cable → 1.6 ltr./55 kW Engine, Mechanics; Rep. Gr.20
	greater than 50	t  Throttle valve potentiometer in the throttle valve control unit -J338- defective or incorrectly set	–  Inspecting throttle valve control unit -J338- → Chapter
		t  Unmetered air between the intake manifold and the air mass meter (results in a higher idling speed)	–  Eliminate unmetered air
9	less than 5	t  high fuel volume from the activated charcoal filter system	–  Testing solenoid valve for activated charcoal filter → Chapter
		t  incorrect injection valves with too high fuel flow rate fitted	–  Testing fuel injected quantity → Chapter
		t  Fuel pressure regulator defective	–  Test fuel pressure regulator and holding pressure → Chapter
	greater than 12	t  increased engine load due to additional electric consumers, air conditioning system switched on, steering wheel ready	–  switch off additional consumers, adjust steering wheel to middle position
10	less than 68	t  Throttle valve jams or is defective	–  Adjusting throttle control cable → 1.6 ltr./55 kW Engine, Mechanics; Rep. Gr.20
		t  large unmetered air volume (cannot be compensated (equalised) by idle stabilizer)	–  Eliminate unmetered air
		t  Idling switch -F60- not closed or defective	–  Interrogate fault memory, check idling switch → Chapter
		t  Throttle valve jams or is defective	–  Adjusting throttle control cable → 1.6 ltr./55 kW Engine, Mechanics; Rep. Gr.20
	greater than 77	t  Throttle valve jams or is defective	–  Adjusting throttle control cable → 1.6 ltr./55 kW Engine, Mechanics; Rep. Gr.20 –  Inspecting throttle valve control unit -J338- → Chapter
		t  Air conditioning switched off	–  Air conditioning switched off

Display group 001

	Reading measured value block			1      →	← Read-out on display
	760...860 rpm	80...110 °C	0...1,0 V	00000000
	1	2	3	4	Display field
					Engine operating condition
				Lambda probe voltage
			Coolant temperature
		Idling speed

Test table - Display group 001

Display field	Display -V.A.G 1552 -	Fault cause	Rectifying fault
1		t  see test table - display group 000, display field 10 → Anchor
2		t  see test table - display group 000, display field 3 → Anchor
3	If the display does not fluctuate (constant 0.00 to 0.30 V or constant 0.7 to 1.00 V)	t  large unmetered air volume	–  Eliminate unmetered air
		t  Spark plug defective	–  Inspect spark plugs
		t  Holding pressure too low or too high	–  Test fuel pressure regulator and holding pressure → Chapter
		t  Injection valve defective	–  Testing injection valves → Chapter
		t  Coolant temperature sender - G62- faulty	–  Test coolant temperature sender -G62- → Chapter
		t  Activated charcoal filter solenoid valve -N80- defective, blocked or jams	–  Testing solenoid valve for activated charcoal filter → Chapter.
		t  Lambda probe heater does not operate	–  Check lambda probe heater → Chapter
		t  Lambda probe defective or dirty	–  Interrogate fault memory → Chapter, if necessary check lambda probe → Chapter
	constant 1.00 V	t  Short circuit to positive through: Lambda probe or signal line or engine control unit	–  Checking lambda probe → Chapter
	continuously between 0.40 to 0.50 V	t  Line interruption through: lambda probe or signal line or engine control unit	–  Checking lambda probe → Chapter
	constant 0.00 V	t  Short circuit to earth through: Lambda probe or signal line or engine control unit	–  Checking lambda probe → Chapter

t	The voltage signal “mixture rich (low level of residual oxygen)” is at approx. 0.7...1.0 V (related to reference mass).

t	The voltage signal “mixture lean (little residual oxygen)” is at approx. 0.0...0.3 V (related to reference mass).

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. Readouts below 0.45 V indicate a lean mixture, above 0.45 V a rich mixture.

Lambda probe voltage Ul 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

Continuation of the test table - Display group 001
Display field	Display -V.A.G 1552-								Meaning of the digits in the 8-digit numerical block (meaning, if display positions = 1)
4	x	x	x	x	x	x	x	x
	1								Fault stored in fault memory
		1							No meaning
			1						Air conditioning compressor on
				1					Open idling switch 1)
					1				Fault in the lambda control 2)
						1			Throttle valve opened
							1		Engine running (speed >1200 rpm)
								1	Coolant temperature below 80°C

1) The reason might be a throttle control cable too tightly adjusted.

2) Not all faults are detected by self-diagnosis. On the display read-out 1, it is essential to check the lambda probe and the lambda control even if no fault has been stored in the fault memory → Chapter.

Display group 002

	Reading measured value block			2      →	← Read-out on display
	760...860 rpm	2.56...6.14 ms	12...14,5 V	15...80 °C
	1	2	3	4	Display field
					Intake manifold temperature
				Battery voltage
			Injection period
		Idling speed

Test table - Display group 002

Display field	Display -V.A.G 1552 -	Fault cause	Rectifying fault
1		t  see test table - display group 000, display field 10 → Anchor
2		t  see test table - display group 000, display field 9 → Anchor
3		t  see test table - display group 000, display field 2 → Anchor
4		t  see test table - display group 000, display field 1 → Anchor

Display group 003

	Reading measured value block			3      →	← Read-out on display
	760...860 rpm	17...34 %	4...10 ∠°	22...41 %
	1	2	3	4	Display field
					On/off ratio (actuation) for throttle valve positioner
				Throttle valve angle
			Engine load signal
		Idling speed

Test table - Display group 003

Display field	Display -V.A.G 1552 -	Fault cause	Rectifying fault
1		t  see test table - display group 000, display field 10 → Anchor
2	Signal outside tolerance	t  Air conditioning on	–  Air conditioning switched off
		t  electrical consumers switched on	–  Switch off consumers
		t  Lambda control on rich or lean load	–  Checking lambda control → Chapter
		t  AC compressor continues operating even though the air conditioning system is switched off	–  Check AC compressor switch → Chapter.
		t  Unmetered air downstream of air-mass meter	–  Eliminate unmetered air
		t  Unmetered air to throttle valve
		t  loosened vacuum hoses	–  Check attachment of vacuum hoses
		t  Fuel pressure regulator defective	–  Test fuel pressure regulator and holding pressure → Chapter
3	less than 4 ∠°	t  Throttle valve potentiometer in the throttle valve control unit defective or incorrectly set	–  Inspecting throttle valve control unit → Chapter
		t  Unmetered air between intake manifold and air mass meter	–  Eliminate unmetered air
	greater than 10 ∠°	t  Basic setting not performed	–  Perform basic setting → Chapter
		t  Throttle valve potentiometer in the throttle valve control unit defective or incorrectly set	–  Inspecting throttle valve control unit → Chapter
		t  Incorrect throttle cable setting	–  Adjust throttle control cable and check → 1.6 ltr./55 kW Engine, Mechanics; Rep. Gr.20
		t  Throttle valve jams
4	less than 22% or more than 41%	t  Air conditioning on	–  Air conditioning switched off
		t  electrical consumers switched on	–  Switch off consumers
		t  Lambda control on rich or lean load	–  Checking lambda control → Chapter
		t  AC compressor continues operating even though the air conditioning system is switched off	–  Check AC compressor switch → Chapter.
		t  Unmetered air to throttle valve	–  Eliminate unmetered air
		t  loosened vacuum hoses	–  Check attachment of vacuum hoses
		t  Fuel pressure regulator	–  Test fuel pressure regulator and holding pressure → Chapter

Display group 004

	Reading measured value block			4      →	← Read-out on display
	760...860 rpm	17...34 %	255	01000000
	1	2	3	4	Display field
					Engine operating condition
				Ignore
			Engine load signal
		Idling speed

Test table - Display group 004

Display field	Display -V.A.G 1552 -	Fault cause	Rectifying fault
1		t  see test table - display group 000, display field 10 → Anchor
2		t  see test table - display group 003, display field 2 → Anchor

Display field	Display -V.A.G 1552-								Meaning of the digits in the 8-digit numerical block (meaning, if display positions = 1)
4	x	x	x	x	x	x	x	x
	1								Trailing throttle
		1							Idling
			1						Partial load
				1					Full load
					1				No meaning
						1			No meaning
							1		No meaning
								1	No meaning

Display group 005

	Reading measured value block			5      →	← Read-out on display
	760...860 rpm	6...19 %	0%
	1	2	3	4	Display field
					not assigned
				Ignore
			On/off ratio (actuation) of solenoid valve for activated charcoal filter
		Idling speed

Test table - Display group 005

Display field	Display -V.A.G 1552 -	Fault cause	Rectifying fault
1		t  see test table - display group 000, display field 10 → Anchor
2	less than 6 % or more than 19 %	t  Activated charcoal filter solenoid valve blocked or jams	–  Testing solenoid valve for activated charcoal filter → Chapter.
		t  Leakage in the ventilation of the fuel system	–  Check vacuum line for leaks.
		t  Leakage in the suction system	–  Check suction system for leaks
		t  Fuel pressure too low or too high	–  Test fuel pressure regulator and holding pressure → Chapter

Display group 006

	Reading measured value block			6      →	← Read-out on display
	75...165	75...165	xxx	20...30
	1	2	3	4	Display field
					Ignore
				Ignore
			Ignore
		Ignore