SEAT Workshop Service and Repair Manuals

Evaluating measured value blocks, display groups 0...6 -Basic functions-

Display group 1 -Basic functions-
l  Engine running at idling speed
Read measured value block 1			→	← Indicated on display
xxxx RPM	xxx °C	x.xxx%	xxxxxxxx
1	2	3	4	← Display fields	Specification	Evaluation
				Adjustment conditions for basic setting	11111111	→
			Lambda regulator before catalytic converter		-15...15%	→
		Coolant temperature			80...110°C	→
	Engine speed (idling speed)				700...900 RPM	→

Significance of 8-digit number block in display field 4 -setting conditions-

Significance if display = 1
1	2	3	4	5	6	7	8	Significance
							1	Coolant temperature above 80 °C
						1		Speed below 2000 RPM
					1			Throttle valve closed
				1				Lambda regulation OK
			1					Idling switch closed
		1						Air conditioner compressor switched off
	1							Catalytic converter pre-heating (above 300 °C)
1								No faults recognised by self-diagnosis

Evaluating display group 1, display field 1 -Engine speed (idling speed)-

Reading -V.A.G 1551-	Possible fault cause	Fault elimination
Lower than specification	t  Throttle valve control part sticking/defective t  Air filter element, very dirty	–  Checking throttle valve control part → Chapter –  Replace dirty air cleaner element → Chapter
Above specification	t  Throttle valve control part sticking/defective t  Large amount of unmetered air (cannot be compensated for by the idling stabilisation)	–  Interrogate fault memory → Chapter –  Check intake system for leaks (unmetered air) → Chapter –  Checking throttle valve control part → Chapter –  Perform idling check → Chapter

Evaluating display group 1, display field 2 -coolant temperature-

Reading -V.A.G 1551-	Possible fault cause	Fault elimination
Less than 80 °C	t  Engine too cold t  Coolant temperature sender or wiring to engine control unit t  Thermostat defective	–  If necessary carry out test drive –  Check coolant temperature sender → Chapter –  Check thermostat → Rep. Gr.19
More than 110 °C	t  Radiator soiled t  Radiator fan not functioning t  Thermostat defective t  Coolant temperature sender or wiring to engine control unit	–  Clean the radiator –  Check functioning t  Check thermostat → Rep. Gr.19 –  Check coolant temperature sender → Chapter

Display group 2 -Basic functions-
l  Engine running at idling speed
Read measured value block 2			→	← Indicated on display
xxxx RPM	xxx.x %	x.x ms	xxx mbar
1	2	3	4	← Display fields	Specification	Evaluation
				Intake manifold pressure	240...420 mbar	→
			Injection period		2.0...4.0 ms	→
		Engine load			10...20 %	→
	Engine speed (idling speed)					→ Anchor

Evaluating display group 2, display field 3 -Injection period-

Reading -V.A.G 1551-	Possible fault cause	Fault elimination
Less than 2 ms	t  Large amount of fuel from the activated charcoal filter system t  Incorrect injectors with greater throughput installed	–  Check fuel tank vent valve → Chapter, control diagnosis –  Check injectors → Chapter –  Checking injector wiring → Parts microfiche
More than 4.0 ms	t  Increased engine load due to electric consumers, air conditioner, or P.A.S. steering on full lock	–  Eliminate load (Air conditioning, Power assisted steering, etc.)

Evaluating display group 2, display field 4 -Intake manifold pressure-

Reading -V.A.G 1551-	Possible fault cause	Fault elimination
Less than 240 mbar	t  Large amount of unmetered air between intake manifold and air cleaner	–  Rectify unmetered air
More than 420 mbar	t  Engine loaded due to ancillaries t  Air cleaner element, very dirty	–  Eliminate increased load (air conditioner, power assisted steering etc.) –  Replace dirty air cleaner element → Chapter

Display group 3 -Basic functions-
l  Engine running at idling speed
Read measured value block 3			→	← Indicated on display
xxxx RPM	xxx mbar	xxx.x %	xx.xo b. TDS
1	2	3	4	← Display fields	Specification	Evaluation
				Ignition timing	0...10° b. TDS	---
			Throttle valve angle (potentiometer 1 -G187-)		0...11%	→
		Intake manifold pressure			240...420 mbar	→
	Engine speed (idling speed)				700...900 RPM	→

Display group 4 -Basic functions-
l  Engine running at idling speed
Read measured value block 4			→	← Indicated on display
xxxx RPM	xx.xxx V	xxx.x °C	xxx.x °C
1	2	3	4	← Display fields	Specification	Evaluation
				Intake air temperature	-40.0...120.0 °C	→
			Coolant temperature		80.0...110.0 °C	→
		Voltage supply for engine control unit			12.0...15.0 V	→
	Engine speed (idling speed)				700...900 RPM	→

Note on display field 3: t  The engine control unit will use the intake air temperature as a replacement value for an engine start (start temperature replacement value) as soon as there is a fault stored in the fault memory, which affects the coolant temperature sender (-G62-). The temperature then rises according to a model stored in the control unit. When the engine has reached normal working temperature a fixed replacement value will be displayed after a certain period. This fixed replacement value depends in turn on intake air temperature. Note on display field 4: t  The total temperature range is given as the specification. The displayed value must be above ambient temperature.

Evaluating display group 4, display field 2 -Control unit voltage supply-

Reading -V.A.G 1551-	Possible fault cause	Fault elimination
Less than 12.000 V	t  Alternator defective, battery charge state low	–  Check voltage, charge battery → Electrical system; Rep. Gr.27
	t  Battery heavily charged shortly after starting due to high charging current and current consumers	–  Increase revs slightly for a few minutes and switch off current consumers
	t  Transfer resistance in the current supply or the engine control unit earth connection	–  Checking voltage supply to engine control unit → Chapter
	t  Current draw when ignition is off	–  Eliminate current draw
More than 15.000 V	t  Voltage regulator on alternator defective	–  Check voltage regulator, replace regulator if necessary → Electrical system; Rep. Gr.27
	t  Excess voltage due to jump starting or quick charging unit	–  Interrogate fault memory → Chapter

Evaluating display group 4, display field 3 -coolant temperature-

Reading -V.A.G 1551-	Possible fault cause	Fault elimination
Less than 80.0 °C	t  Engine too cold	–  If necessary carry out test drive
	t  Coolant temperature sender or wiring to engine control unit	–  Check coolant temperature sender → Chapter
More than 110.0 °C	t  Radiator soiled	–  Clean the radiator
	t  Radiator fan not functioning	–  Checking function
	t  Thermostat defective	–  Check thermostat → Rep. Gr.19
	t  Coolant temperature sender or wiring to engine control unit	–  Check coolant temperature sender → Chapter
-40 °C constant	t  Wiring open circuit or short to positive	–  Check coolant temperature sender → Chapter
120 °C constant	t  Short to earth

Evaluating display group 4, display field 4 -intake air temperature-

Reading -V.A.G 1551-	Possible fault cause	Fault elimination
-40.0 °C constant	t  Wiring open circuit or short to positive	–  Checking intake air temperature sender → Chapter
120,0 °C constant	t  Short to earth

Display group 5 -Basic functions-
l  Engine running at idling speed
Read measured value block 5			→	← Indicated on display
xxxx RPM	xxx %	xxx km/h	Text
1	2	3	4	← Display fields	Specification	Evaluation
				Engine operating conditions: (idling, part load, enrichment, overrun, full load)	Idling	---
			Road speed		0 km/h	---
		Engine load			10...20 %	→
	Engine speed (idling speed)				700...900 RPM	→

Display group 6 -Basic functions-
l  Engine running at idling speed
Read measured value block 6			→	← Indicated on display
xxxx RPM	xxx.x %	xxx.x °C	xx.x %
1	2	3	4	← Display fields	Specification	Evaluation
				Altitude correction factor	-30.0...5.0 %	---
			Intake air temperature		-40.0...120.0 °C	→
		Engine load			10...20 %	→
	Engine speed (idling speed)				700...900 RPM	→