SEAT Workshop Service and Repair Manuals

Evaluating measured value block, display groups 10...29 -Ignition-

Display group 10 -Ignition-
l  Engine running at idling speed
Read measured value block 10			→	← Indicated on display
xxxx RPM	xxx.x %	xxx.x %	xx.xo b. TDS
1	2	3	4	← Display fields	Specification	Evaluation
				Ignition timing	0...10° b. TDC	---
			(Potentiometer 1 -G187-)		0...11%	→
		Engine load			10...20 %	→
	Engine speed (idling speed)				700...900 RPM	→

Evaluating display group 10, display field 2 -engine load-

Reading -V.A.G 1551-	Possible fault cause	Fault elimination
Less than 10 %	t  Lesser values can only occur when driving in overrun	---
More than 20 %	t  Rough idling (not running on all cylinders)	–  Check injectors → Chapter –  Check ignition cables and spark plugs → Chapter
	t  Throttle valve control part defective	–  Checking throttle valve control part → Chapter
	t  Electric consumers switched on	–  Switch off electric consumers
	t  Steering wheel at full lock	–  Set steering wheel to centre position

Evaluating display group 10, display field 3 -Throttle valve angle, potentiometer 1-

Reading -V.A.G 1551-	Possible fault cause	Fault elimination
More than 11 %	t  Engine control unit not matched to throttle valve control part	–  Adapt engine control unit to throttle valve control part → Chapter
	t  Throttle valve potentiometer in throttle valve control part defective	–  Checking throttle valve control part → Chapter
	t  Throttle valve sticking t  Air cleaner element, very dirty	–  Rectify cause –  Replace dirty air cleaner element → Chapter

Display group 14 -Ignition - Misfire sum-
l  Whilst driving
Read measured value block 14			→	← Indicated on display
xxxx RPM	xx.x %	xxx	Text
1	2	3	4	← Display fields	Specification	Evaluation
				Misfire detection (active, not active)	activated	_
			Misfire total		0	→
		Engine load			12...100%	_
	Engine speed				800...5700 RPM	_

Evaluating display group 14, display field 3 -total number of misfires-

Reading -V.A.G 1551-	Possible fault cause	Fault elimination
More than 0	t  Spark plug defective t  Spark plug connector defective t  Ignition coil defective	–  Check the spark plugs and ignition/H.T. cables with connectors → Chapter –  Check ignition transformer → Chapter
	t  Injector defective	–  Check injectors → Chapter
	t  Exhaust gas recirculation valve sticking	–  Check exhaust gas recirculation valve → Chapter, Final control diagnosis

Display group 15 -Ignition - Misfire recognition, cyl. 1 to cyl. 3-
l  Whilst driving
Read measured value block 15			→	← Indicated on display
xxx	xxx	xxx	Text
1	2	3	4	← Display fields	Specification	Evaluation
				Misfire detection (active, not active)	activated	---
			Misfiring in cyl. 3		0	→ Anchor
		Misfiring in cyl. 2			0	→ Anchor
	Misfiring in cyl. 1				0	→ Anchor

Display group 16 -Ignition - Misfire recognition, cyl. 1 to cyl. 4-
l  Whilst driving
Read measured value block 16			→	← Indicated on display
xxx	---	---	Text
1	2	3	4	← Display fields	Specification	Evaluation
				Misfire detection (active, not active)	activated	_
	Misfiring in cyl. 4				0	→ Anchor

Evaluating display group 15, display fields 1 to 3, or display group 16, display field 1 -Total number of misfires, cyls. 1 to 4-

Reading -V.A.G 1551-	Possible fault cause	Fault elimination
More than 0	t  Spark plug defective t  Spark plug connector defective t  Ignition coil defective	–  Check the spark plugs and ignition/H.T. cables with connectors → Chapter –  Check ignition transformer → Chapter
	t  Injector defective	–  Check injectors → Chapter
	t  Exhaust gas recirculation valve sticking	–  Check exhaust gas recirculation valve → Chapter, Final control diagnosis

Display group 22 -Ignition - Knock control-
l  Whilst driving
Read measured value block 22			→	← Indicated on display
xxxx RPM	x.xx%	xx.x ° kW	xx.x ° kW
1	2	3	4	← Display fields	Specification	Evaluation
				Cyl. No. 2: retardation of ignition timing by knock control	0...14° crankshaft	→
			Cyl. No. 1: retardation of ignition timing by knock control		0...14° crankshaft	→
		Engine load			12...100%	---
	Engine speed				800...5700 RPM	---

Note on display field 3 and 4: t  At idling revs, reading should be 0.0° crankshaft.

Display group 23 -Ignition - Knock control-
l  Whilst driving
Read measured value block 23			→	← Indicated on display
xxxx RPM	x.xx%	xx.x ° kW	xx.x ° kW
1	2	3	4	← Display fields	Specification	Evaluation
				Cyl. No. 4: retardation of ignition timing by knock control	0...14° crankshaft	→
			Cyl. No. 3: retardation of ignition timing by knock control		0...14° crankshaft	→
		Engine load			12...100%	---
	Engine speed				800...5700 RPM	---

Note on display field 3 and 4: t  At idling revs, reading should be 0.0° crankshaft.

Evaluating display groups 22/23, display fields 3 and 4 -retardation of ignition-

Reading -V.A.G 1551-	Possible fault cause	Fault elimination
All cylinders above 14° crankshaft	t  Knock sensor defective	–  Check knock sensor → Chapter
	t  Connector corroded
	t  Knock sensor incorrectly tightened	–  Loosen knock sensor and tighten to 20 Nm
	t  Ancillary components on engine loose	–  Tighten ancillary components
	t  Poor fuel quality	–  Change type of fuel
One cylinder deviates greatly from the others	t  Connector corroded	–  Check knock sensor → Chapter
	t  Engine damaged	–  Check compression pressures → Rep. Gr.15
	t  Ancillary components on engine loose	–  Tighten ancillary components

Display group 28 -Ignition - Knock control-
l  Whilst driving
Read measured value block 28			→	← Indicated on display
xxxx RPM	xx.x %	xxx.x oC	Text
1	2	3	4	← Display fields	Specification	Evaluation
				Result of knock sensor check (test ON/test OFF/syst.OK/syst.Not OK)	syst.OK	---
			Coolant temperature		80...110 °C	→
		Engine load			12...100%	---
	Engine speed				2000...4000 RPM	---