28-1
Digifant Ignition system, component
layout
Vehicles built up to m.y. 1995
Only Ignition system information covered in this . For
Fuel injection system information:
Repair Manual , Fuel Injection & Ignition, Repair Group 24
The Fuel injection/Ignition Engine Control Module is
equipped with On Board Diagnostic Functions
Components identified with an asterisk * are checked via
On Board Diagnostic
Before repairs and troubleshooting, check DTC Memory,
repair as needed and then erase DTC Memory
Repair Manual , Fuel Injection & Ignition, Repair Group 01
Always observe Safety Precautions
Page 28-8
Checking, adjusting, tune-up and spark plug data
Page 28-7
28-2
1 - Ignition coil
checking
Page 28-19
location: in driving direction left, under battery cover
2 - Terminal 4
3 - Terminal 15
4 - Terminal 1
5 - Ignition coil power output stage -N157checking
Page 28-20
6 - Distributor cap connector for spark plug wire(s)
RF suppression
resistance check: 600 to 1400 Ohms
7 - Camshaft Position sensor harness connector
8 - Dust cap
9 - Ignition rotor
identification "R1"
resistance check: 600 to 1400 Ohms
10 - Distributor cap
- Check for cracks and leaks
- Check for contact wear
- Clean before installing
- Check carbon brush for wear and clearance
28-3
11 - RF shield for distributor cap
12 - Ignition wire
- Check for continuity
13 - Spark plug connector
shielded
resistance check: 4000 to 6000 Ohms
14 - Spark plug
specifications and data
Page 28-7
15 - 10 Nm (7 ft lb)
16 - Ignition distributor housing
w/Camshaft Position sensor -G40-*
disassembling and assembling
installing:
Page 28-6
Page 28-9
checking ignition timing point and adjusting:
28-11
Cam Position sensor, checking:
17 - O-ring
- Replace if damaged
18 - Ground strap
Page 28-17
Page
fastened to housing
28-4
Engine Control Module (ECM), component layout
1 - Ground connection
fastened to body
2 - 38-pin ECM harness connector
- Switch OFF ignition before disconnecting or
connecting
3 - Vacuum line
to intake hose of return valve between intake hose
and brake booster
Repair Manual , Fuel Injection & Ignition, Repair Group 24
for Manifold Absolute Pressure sensor -G71-* inside
of ECM -J169-*
4 - Digifant Engine Control Module -J169-*
for Fuel injection system, Oxygen sensor control,
rpm limit, ignition and On Board Diagnostic
location: left engine compartment
with MAP sensor -G71-*, checking
- If replaced, check idle speed
Page 24-46
Page 24-24
28-5
5 - Engine Coolant Temperature sensor harness
connector
6 - Engine Coolant Temperature sensor -G62-*
blue
2-pin
- Reduce cooling system pressure before removing
checking
Page 24-41
resistance values
Page 01-92
7 - Throttle Position sensor -G69-*
3-point connection for manual transmission vehicles
4-point connector for automatic transmission
vehicles. (signal goes to Transmission Control
Module -J217-)
checking:
Page 24-38
- Before replacing, perform idle check
23
Page 24-
28-6
Ignition distributor, disassembly and assembly
Note:
During assembly, be sure that the clutch (item 8) on pin (item
7) moves easily, and distributor shaft play for item 1 is not
reduced.
1 - Ignition distributor shaft
with trigger wheel
- Pull out of housing after removing pin (item 7)
2 - Washers
3 - Plastic spacer
4 - 3 Nm (27 inch lb)
5 - Camshaft Position sensor -G40Checking:
Page 28-17
- Ensure that it is securely installed in distributor
housing (item 6)
6 - Ignition distributor housing
7 - Pin
8 - Coupling
-
Before removing; position drive pin toward
distributor shaft (item 1)
28-7
Tune-up, spark plugs and adjusting data
Engine Code
AAF
Ignition timing point:
Checking value
4 to 8
BTDC
Adjusting value
6
BTDC
These values checked / adjusted
at
2000 to
2500/RPM
Firing order
1-2-4-5-3
1
Spark plugs
Champion 101 000 026 AA
N9 BMC
Electrode gap
0.7 to 0.9 mm
Tightening torque
25 Nm (18 ft lb)
28-8
Safety precautions
CAUTION!
Observe the following precautions to avoid
personal injury as well as possible damage to
the ignition system.
DO NOT touch or remove ignition wires while
the engine is running and/or while cranking
always switch OFF the ignition BEFORE
disconnecting or connecting wiring or test
measurements
disconnect the engine speed sender (on
lower left side of cylinder head on bracket)
whenever the engine requires cranking
without starting, such as checking
compression.
DO NOT connect any condensers to terminal
1 (-).
DO NOT replace the distributor rotor
(identification: R1) with anything except the
production part, even for RF suppression.
for RF suppression only use 1000 Ohm
resistance and spark plug wires with 5000
Ohms.
28-9
Ignition distributor, installing
Engine installed
- Position flywheel at TDC as shown in views A and B
Engine removed
- Align marking on vibration damper C with marking on lower toothed belt guard
(arrow)
- Align mark on camshaft sprocket with marking on rear toothed belt guard (arrow)
28-10
- Turn rotor until it points to cyl. 1 mark on distributor housing
- Insert distributor into engine (watch out for nearby components and obstructions)
- Clean distributor cap and inspect for cracks, tracking etc. before installing,
replace if necessary
- Start engine and let idle
- Check ignition timing, adjust if necessary
28-11
Ignition timing point, checking and
adjusting
Requirement
Engine cold
Note
Some vehicles require a TDC sensor along with
adaptor VAG 1367/9. Connect the ignition tester
to these vehicles with engine warm and without
removing the distributor cap.
- Remove splash shield from distributor
- Connect VAG 1367 engine tester using VAG 1367/8 inductive pickup
- Connect VAG 1551 Scan Tool
Page 01-4
- Start engine and let idle until warm
engine oil 80
C (176
F) minimum
below 1500 rpm
Note
If the engine stalls or shuts off, it can run at increased idle speed for up to 4
minutes after re-starting. In this case wait until engine speed drops before
measuring the timing.
28-12
- Operate VAG 1551 with respect to the displays
shown
- Press 1 to obtain Rapid data transfer
- Press 0 and 1 buttons to select address word
01:"Engine electronics"
- Press Q button to enter input
- Press
button
- Press 0 and 4 buttons to select Function 04:
"Engine basic setting"
- Press Q button to enter input
Note
When Function 04 is selected, the idle speed is
coordinated with the engine via the ECM.
Introduction of basic setting
HELP
Display will appear as shown
Indicator group number input
- Press the 0 button twice to select the indicator group number
- Press Q button to enter input
28-13
Display will appear as shown
System in basic adjustment
1
2
3
4
5
6
7
8
9
10
or
Function unknown/or can not be conducted
If the display appears as shown
at this time
- Check the following possibilities:
Coolant temperature of 85
C minimum not yet obtained
Idle speed exceeds 1500 rpm
Function 04 "Basic setting" using VAG 1551 Scan Tool is not possible
If YES
- Disconnect blue Engine Coolant Temperature sensor harness connector (with
throttle removed) -arrowNote:
If the engine shuts off; before restarting, re-connect the ECT harness connector;
otherwise, the Digifant Engine Control Module will default to an emergency program
making a test/adjustment impossible.
- Check ignition timing point
Between 2000 and 2500 RPM
Ignition timing must be between 4 and 8
BTDC and fluctuating
28-14
Ignition timing, checking with strobe light
Ignition timing mark flashes
- Adjust ignition timing point by turning the distributor
- Press
button to end Function 04: "Basic setting"
Radiator cooling fan must not be running during measurement
- Check and erase Diagnostic Trouble Code memory
Repair Manual , Fuel Injection & Ignition, Repair Group 01
this will erase the stored DTC caused by disconnecting ECT sensor -G62- Correct idle adjustment if necessary via Function 04:"Engine basic setting"
Page 24-24
- Press 0 and 6 buttons to select Function 06: "End data transfer"
- Press Q button to enter input
- Allow engine to cool
- Remove splash shield from distributor cap
- Remove VAG 1367 TDC sender from bell housing
28-15
Ignition timing advance (map),
checking/adjusting
Requirements
Ignition timing point adjustment OK
DTC memory clear
Engine cold
Note
Some vehicles require TDC sensor and adaptor
VAG 1367/9. The ignition tester can be
connected to these vehicles with the engine
warm and without removing the distributor cap.
- Remove splash shield from distributor cap
- Connect VAG 1367 engine tester using VAG 1367/8 inductive pickup
- Connect VAG 1551 Scan Tool
Page 01-4
- Start engine and let run until warm
Engine oil 80
C (176
F) minimum
- Raise engine speed from idle to 2200 rpm
28-16
49 States: 26 to 36
BTDC
California 15 to 38
BTDC
- Slowly raise engine speed to slightly exceed 2200 RPM until the ignition timing
point (adjustment value) is displayed
49 States
26 to 36
BTDC
California 15 to 38
BTDC
If ignition timing point does not change
- Perform electrical check, Test step 10 or 27
Page 01-32
Note:
Use the VAG 1598 Test Box to perform these checks. If Test Box is not available,
check Camshaft Position sensor Page 28-17 .
28-17
Camshaft Position sensor, checking
Voltage supply, checking
- Disconnect Camshaft Position sensor harness
connector at ignition distributor
- Switch Fluke 83 multimeter to 20 Volt range
- Connect multimeter to outer terminals of connector using jumper wires from VW
1594 adaptor kit
- Switch ON ignition
must be 10 Volts minimum
If NO
- Replace Engine Control Module -J169- Switch OFF ignition
Function, checking
- Disconnect cold start valve harness connector
- Disconnect fuel injector harness connector at fuel rail
- Slide up the rubber boot on the Camshaft Position sensor harness connector (at
ignition distributor)
- Re-connect Camshaft Position sensor connector
28-18
- Connect VAG 1527B LED tester to center terminal and brown / white outer wire
of Camshaft Position sensor connector (while connected) using jumper wires
from the VW 1594 adaptor kit
- Operate starter
LED tester must flicker
If NO
- Replace Camshaft Position sensor
28-19
Ignition coil, checking
- Disconnect ignition wire and harness connector
from ignition coil
- Switch Fluke 83 multimeter to resistance
range
- Connect multimeter between ignition coil terminals 1 and 15 using jumper wires
from VW 1594 adaptor kit
- Measure primary resistance
must be 0.5 to 0.7 Ohms
- Connect multimeter between terminals 4 and 15
- Measure secondary resistance
must be 3000 to 4000 Ohms
If NO
- Replace ignition coil -N152- and power output stage -N157- Repeat test
28-20
Power output stage, checking
Requirements
Electrical check, Test steps 6 or 23 OK
01-32
Page
Ignition coil OK
Voltage supply, checking
- Remove 3-pin connector from ignition coil
- Switch Fluke 83 multimeter to 20 Volt range
- Connect multimeter between terminals 1 and 3 of connector using jumper wires
from VW 1594 adaptor kit
- Switch ON ignition
must be approximately battery voltage
- Switch OFF ignition
Triggering, checking
- Disconnect cold start valve harness connector
- Disconnect fuel injector harness connector at fuel rail
- Connect VAG 1527B LED tester between terminals 2 and 3 of connector 4 using
adaptor VW 1594/15 from adaptor kit VW 1594
28-21
- Operate starter and check ignition signal from
ECM
LED tester must flicker
If NO
- Check Camshaft Position sensor
17
Page 28-
If Camshaft Position sensor OK
- Replace ECM -J169- Connect 3-pin harness connector and ignition
wire to ignition coil
- Connect VAG 1527B LED tester between terminals 1 and 15 of ignition coil
using jumper wires from VW 1594
WARNING!
Electrical shock hazard. DO NOT touch the ignition coil terminals or test
connections during following check.
- Switch ON ignition
LED tester must light up for 1 to 2 seconds
- Operate starter
LED tester must flicker
If NO
- Replace ignition coil power output stage