SEAT Workshop Service and Repair Manuals

Analysis measured value block, display groups 0...6 -basic functions-

Display group 1 -basic functions-
l  Engine idling
Read measured value block 1			→	◂ Message on the display
xxxx rpm	xxx °C	x.xxx %	xxxxxxxx
1	2	3	4	◂ Display fields	Target value	Analysis
				Conditions for basic settings	11111111	→ Chapter
			Lambda control value		-15...15 %	→ Chapter
		Coolant temperature			80...110 °C	→ Chapter
	Engine revs (idling revs)				640...930 rpm	→ Anchor

Meaning of the 8-digit numerical block, display field 4 -conditions of settings-

Meaning if digit = 1
1	2	3	4	5	6	7	8	Meaning
							1	Coolant temperature above 80 °C
						1		Revs less than 2000 rpm
					1			Throttle valve closed
				1				Lambda control, OK
			1					Idle switch OFF
		1						Air conditioning compressor off
	1							Catalyst preheating (above 300 °C)
1								No fault found via the self-diagnosis

Analysis display group 1, display field 1 - engine revs (idling revs)

Display -V.A.G. 1551-	Possible cause of the fault	Elimination of the fault
less than 640 rpm	t  Throttle valve control unit, jammed	–  Test the throttle valve control unit → Chapter
	t  Air filter very dirty
more than 930 rpm	t  Significant amount of infiltrated air (not compensable with idle stabilisation)	–  Consult the fault memory → Anchor, Fault memory: consulting and clearing
	t  Throttle valve control unit, jammed or faulty	–  Test the throttle valve control unit → Chapter
		–  Test the intake system for leakage → Anchor

Analysis display group 1, display field 2 - coolant temperature

Display -V.A.G. 1551-	Possible cause of the fault	Elimination of the fault
less than 80 °C	t  Engine very cold	–  If necessary, road test
	t  Coolant temperature sender or wiring to engine control unit	–  Test the coolant temperature sender → Chapter
over 110 °C	t  Radiator dirty	t  Clean the radiator
	t  Radiator fan does not work	t  Test the functioning
	t  Thermostat faulty	t  Test the thermostat → Rep. Gr.19
	t  Coolant temperature sender or wiring to engine control unit	–  Test the coolant temperature sender → Chapter

Display group 2 -basic functions-
l  Engine idling
Read measured value block 2			→	◂ Message on the display
xxxx rpm	xxx.x %	x.x ms	xxx mbar
1	2	3	4	◂ Display fields	Target value	Analysis
				Intake manifold pressure	240...480 mbar	→ Chapter
			Injection timing		2.0...5.0 ms	→ Chapter
		Engine load			10...20 %	→ Chapter
	Engine revs (idling revs)				640...930 rpm	→ Anchor

Analysis display group 2, display field 3 - injection timing

Display -V.A.G. 1551-	Possible cause of the fault	Elimination of the fault
less than 2.0 ms	t  Significant fuel flow from the activated charcoal filter system	–  Test solenoid valve 1 for the activated charcoal filter → Chapter, Final control diagnosis
	t  There are incorrect injectors installed with greater flow	–  Test the injection flow → Chapter
over 5.0 ms	t  High engine load due to electrical consumers, air conditioning or power steering to limit	–  Eliminate the extra load (Air conditioning, power steering, etc.)

Analysis display group 2, display field 4 - intake manifold pressure

Display -V.A.G. 1551-	Possible cause of the fault	Elimination of the fault
less than 240 mbar	t  Significant quantity of infiltrated air between the intake manifold and the air filter	–  Test the intake system for leakage → Anchor
over 480 mbar	t  Engine subject to load from supplementary mechanical groups	–  Eliminate the extra load (Air conditioning, power steering, etc.)

Display group 3 -basic functions-
l  Engine idling
Read measur. value block 3			→	◂ The display reads
xxxx/min	xxx mbar	xxx.x %	xx.x° before TDC
1	2	3	4	◂ Display fields	Target value	Analysis
				Ignition angle	0...10° before TDC	--
			Throttle valve angle (potentiometer 1 -G187-)		0...11 %	→ Anchor
		Intake manifold pressure			240...480 mbar
	Engine revs (idling revs)				640...930/min

Display group 4 -basic functions-
l  Engine idling
Read measur. value block 4			→	◂ The display reads
xxxx/min	xx.xxx V	xxx.x °C	xxx.x °C
1	2	3	4	◂ Display fields	Target value	Analysis
				Intake air temperature	-40...120.0 °C	→ Anchor
			Coolant temperature		80...110 °C
		Engine control unit voltage supply			12.0...15.0 V
	Engine revs (idling revs)				640...930/min

Analysis display group 4, display field 2 - voltage supply of the engine control unit

Display -V.A.G. 1551-	Possible cause of the fault	Elimination of the fault
less than 12.000 V	t  Alternator faulty, battery very low	–  Test the alternator and battery voltage, charge the battery → Electrical system; Rep. Gr.27
	t  Battery subject to high load shortly after start-up due to high current load and supplementary mechanical units	–  Raise the revs for a few minutes and switch off the supplementary consumers
	t  Contact resistance in voltage supply, or at the earth connection of the engine control unit	–  Test the voltage supply of the engine control unit → Chapter
	t  Electrical consumption when the ignition is off	–  Eliminate the electrical consumption
over 15.000 V	t  Alternator voltage regulator, faulty	–  Test voltage regulator; replace the regulator if necessary → Electrical system; Rep. Gr.27
	t  Excess voltage due to start-up with auxiliary leads or quick charger	–  Consult the fault memory → Anchor, Fault memory: consulting and clearing

Analysis display group 4, display field 3 - coolant temperature

Display -V.A.G. 1551-	Possible cause of the fault	Elimination of the fault
less than 80.0 °C	t  Engine very cold	–  If necessary, road test
	t  Coolant temperature sender or wiring to engine control unit	–  Test the coolant temperature sender → Chapter
over 110.0 °C	t  Radiator dirty	–  Clean the radiator
	t  Radiator fan does not work	–  Test the functioning
	t  Thermostat faulty	–  Test the thermostat → Rep. Gr.19
	t  Coolant temperature sender or wiring to engine control unit	–  Test the coolant temperature sender → Chapter
-40 °C constant	t  Open circuit in wiring	–  Test the coolant temperature sender → Chapter
120 °C constant	t  Short circuit between wires 1 and 3

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

Display -V.A.G. 1551-	Possible cause of the fault	Elimination of the fault
-40.0 °C constant	t  Open circuit or short circuit to positive	–  Test the intake air temperature sender → Chapter
120.0 °C constant	t  Short circuit to earth

Display group 5 -basic functions-
l  Engine idling
Read measured value block 5			→	◂ Message on the display
xxxx rpm	xxx %	xxx km/h	text
1	2	3	4	◂ Display fields	Target value	Analysis
				Engine load state (idling, half load, enrichment, deceleration, full load)	Idling	---
			Running speed		0 km/h	---
		Engine load			10...20 %	→ Chapter
	Engine revs (idling revs)				640...930 rpm	→ Anchor

Display group 6 -basic functions-
l  Engine idling
Read measured value block 6			→	◂ Message on the display
xxxx rpm	xxx.x %	xxx.x °C	xx.x %
1	2	3	4	◂ Display fields	Target value	Analysis
				Correction factor depending on altitude	-40.0...5.0 %	---
			Intake air temperature		-48...143 °C	→ Chapter
		Engine load			10...20 %	→ Chapter
	Engine revs (idling revs)				640...930 rpm	→ Anchor

t	Note on the display field 3:

t	The whole temperature range is displayed as the target value. The value displayed should be higher than ambient temperature.