1988 CITROEN CX ignition

CHECKING THE INTEGRATED ELECTRONlC
IGNITION (I.E.I.)
TEST PROCEDURE USING CONVENTIONAL EQUIPMENT
on the CX 2500 vehicle with M 25/659 type engine
l Checking the voltage in the secondary winding of each coil
0 Operating procedure: Disconnect one sparking plug and bring the end of the released wire 1 cm approx
from the crankcase. (Repeat the operation for each set of cylinders).
l Operate the starter motor:
if a spark occurs The incident is not to be attributed to the I.E.I.
Check the injection system, the valve timing, the rockers etc.
- examine the engine sparking plugs.
- inspect the circuit between the I.E.I. control unit white terminal 1 and the fuel
injection control unit terminal 15 for continuity: read 0 0, the connectors from
the control units being disconnected.
if no spark occurs The incident is due to the ignition system--ccarry on to next tests.
l Working on the primary winding of each coil
Operating procedure: Connect a 12V warning lamp of the Wedge base type between the negative and
0 the positive terminals of the coil (i.e. between terminals 1 and 3, connectors con-
netted to coil).
l Operate the starter motor:
if no regular breaks occur incident in the coil primary winding
or
incident in the E.C.U. control circuit.
if regular breaks occur incident in the secondary winding
The following checks are to be carried out with I.E.I. and fuel injection control units connectors disconnected.
l Checking the coil primary windings:
Operating procedure: Measure the resistance between terminals 1 and 9 of the I.E.I. control unit black
0 connector: Read = 2.5 0.
Warning: the ignition should be switched off.
If the reading is incorrect, investigate for a failure in this circuit.
l Checking the E.C.U. pick up sensors:
co Operating procedure: Measure the resistance between terminals 5 and 12 then 6 and 13 of the I.E.I.
control unit black connector: Read = 50 a.
l Checking the feed for the E.C.U. and earth connection, with ignition switched on
Operating procedure: Measure the voltage between terminals IO (white connector) and 2 (black con-
nector) of the I.E.I. computer: Read the battery voltage.
The same check should be carried out between terminals 2 (earth) and 11 of the black connector:
ignition switched on, starter motor operated, read the voltage.
69 l Check that the distance between the datum sensor and the flywheel ring is 1 mm + 0.5.
0 l Incident on the ignition circuit secondary winding: make sure that the resistance of each coil
winding is: 350014000 a.
8531

CHECKING THE I.E.I.
TEST PROCEDURE USING CONVENTIONAL EQUIPMENT
on the CX 2500 Turbo vehicle with M 25/662 type engine
0 Checking the voltage in the secondary winding of each coil
0 Operating procedure: Disconnect one sparking plug and bring the end of the released wire 1 cm approx
from the crankcase. (Repeat the operation for each set of cylinders).
0 Operate the starter motor,
if a spark occurs
if no spark occurs The incident is not to be attributed to the I.E.I.
Check the injection system, the valve timing, the rockers etc.
- examine the engine sparking plugs.
- inspect the circuit between the I.E.I. control unit white terminal 1 and the fuel
injection control unit terminal 15 for continuity: read 0 Q, the connectors from
the control units being disconnected.
The incident is due to the ignition system-carry on to next tests.
l Working on the primary winding of each coil
Operating procedure: Connect a 12V warning lamp of the Wedge base type between the negative and
the positive terminals of the coil (i.e. between terminals 1 and 3, connectors con-
netted to coil).
l Operate the starter motor,
if no regular breaks occur incident in the coil primary winding
or
incident in the E.C.U. control circuit.
if regular breaks occur incident in the secondary winding
The following checks are to be carried out with I.E.I. and fuel injection control units connectors disconnected.
0 Checking the coil primary windings:
Operating procedure: Measure the resistance between terminals 1 and 9 of the I.E.I. control unit black
0 connector: Read = 2.5 Q.
Warning: the ignition should be switched off.
If the reading is incorrect, investigate for a failure in this circuit.
l Checking the E.C.U. pick up sensors:
OI Operating procedure: Measure the resistance between terminals 5 and 12 then 6 and 13 of the I.E.I.
4
control unit black connector: Read 2: 5OQ
0 Checking the feed for the E.C.U. and earth connection, with ignition switched on.
d 5 Operating procedure: Measure the voltage between terminals 10 (white connector) and 2 (black con-
nectar) of the I.E.I. computer: Read the battery voltage.
The same check should be carried out between terminals 2 (earth) and 11 of the black connector:
ignition switched on, starter motor operated, read the voltage.
@ 0 Check that the distance between the datum sensor and the flywheel ring is 1 mm + 0.5.
0 * Incident on the ignition circuit secondary winding: make sure that the resistance of each coil
winding is: 350014OOOQ.

CHECKING THE IGNITION SYSTEM
USING CHECKING EQUIPMENT OUT 106 029T
The instrument can be utilised on CX 2400 I.E. with naturally aspirated engine and CX 2500 I.E. TURBO. Howe-
ver, on CX 2400 I.E. having an integrated electronic ignition system with a single connector E.C.U., it is neces-
sary to proceed as follows:
- connect the I.E.I. control unit to the black connector of OUT 105 029.T
- set the switch of the apparatus to the “1 connector” position
- I.E.I. with 1 or 2 sensors can be checked with this device.
a) Testing the ignition coil primary winding:
- The warning lamps, one at each coil, blink rythmically with the impulses transmitted to their primary win-
ding. Steady blinks indicate that there is enough current to generate a spark in the secondary winding.
- The switch situated under the warning lamps makes it possible for the primary windings of both coils to
be insulated, by pushing, in the “out of circuit“ position, any interference coming from the HT circuit when
the frequency of illumination for sensor warning lamps is checked.
- If the warning lamps blinking is correct, the failure may be caused by:
- the ignition information to the fuel injection control unit, (paragraph c),
- the secondary winding (coil wires, coils),
- any other item required for a correct operation of the engine such as injection, valve gear, rockers etc.) -
If the warning lamps blinking is not correct, examine the control unit warning lamps, (paragraph b),
b) Testing the sensors: -
The warning lamp connected with the “datum” sensor blinks rythmically with the impulses transmitted by
the peg, i.e. one blink per engine revolution, (2 sensors fitted).
- The warning lamp connected with the “flywheel pick up” sensor, blinks rythmically with the impulses sent ’
by the flywheel teeth.
The frequency of the flashes is such as they can hardly be seen.
Apparently, the lamp stays on, (1 or 2 sensors fitted).
On the CX 2400 I.E. and 2500 I.E. with normally aspirated engine, the vacuum pressure warning lamp lights
up momentarily after a sharp acceleration: this warning lamp is no longer usable on the CX 2500 I.E. with
turbocharger.
c) Tests related with the I.E.I. control unit:
E.C.U. functions: -
The rev. counter warning lamp blinks rythmically with the impulses transmitted to the rev. counter.
- The injection warning lamp blinks rythmically with the impulses sent to the fuel injection control unit
+k 8531

CHECKING THE IGNlTlON ADVANCE
of the I.E.I. system
On CX vehicles fitted with I.E.I.
These vehicles having fixed sensors, are not equipped with TDC sensors
I) Marking the TDC:
Draw a mark on the crankcase, in the opening located next to the flywheel pick up sensor
- Remove the 1st or 4th cylinder sparking plug
- Finding the T.D.C. with a locating peg: jack up the vehicle on one side and engage a gear.
Rotate the road wheel in one direction.
Mark down the place where locating pin will enter the flywheel.
Draw a temporary line on the flywheel ring. Rotate the lifted road wheel in the opposite direction, with
the pin still engaged. Mark the position of the pin in the flywheel ring. Take an average of these two marks-
which corresponds to the TDC. Draw a white paint mark on the flywheel ring, opposite the one on the
crankcase.
- Refit the sparking plug.
2) Testing the development of the speedometer advance curve:
- Connect a phase shifting strobe lamp
- Set the strobe lamp to the 2 cyl. u stroke or 1 cyl. 2 stroke position.
- Disconnect the pipe of the load correction depression operated capsule from the inlet manifold. Blank
off the orifice.
- Run the engine and check the advance curve development.
3) Testing the operation of the air-operated capsule on normally aspirated engines:
- Blank off the vacuum capsule venting orifice.
- Connect a vacuum pump to the capsule pipe.
- Run the engine to 2.000 rpm; record the advance reading.
- Create a 400 mbar depression in the vacuum capsule.
The ignition advance increases by about 15’ and the engine accelerates to 200 rpm approx.
On turbocharged engines:
- Connect a vacuum-pressure pump to the capsule pipe.
- Rotate the engine to 200 rpm. Read the advance.
- Build up a 500 mbar depression in the capsule:
- There will be a 22” increase of the ignition advance, approx. and about a 500 rpm engine acceleration.
- Build up a 500 mbar pressure in the capsule:
- There will be a -1 1 o decrease of the ignition advance, approx. and about a 500 rpm engine slowing down
- Pinking: occurs when the engine speed exceeds 1.000 rpm. The warning lamp should light up in the
following cases:
- anti-knock sensor system broken or short-circuited,
- knock sensor broken or short circuited,
- improper earthing provided by the knock sensor.
- Check the operation with the strobe lamp, and a 2.000 rpm engine speed Record the ignition timing.
- Disconnect the knock sensor:
The ignition advance decreases by IO’ approx.

2 MA
510.00/1 ELECTRICAL JUNCTION BOX
Colour Colour
CJ)
”
2
a,
E --Pi- Function ”
i
-1
5 z 2 iz az?i”; cg Function
,%“~o” -0
2% z 2:
om 02’ 2%
Es p 2 f
“v)Z”” i53 s 22
S2r”~S 0% zi ‘i’ F
G,c
125M 1JM Earth 106-201 211
III 5 3 Bl 1 J Mv + lgnttron 40
On Harness 3 J 2 v L/H Front Srde Lamp 201
2 V Mv
G + lgnrtion Swatch 38
Main Beam 212 3V B Tachometer 66
4G V Dipped Beam
G 213
5 V BI L/H Drrectron lndrcator 107
III 6 6 B 1 J Mv + lgnrtron Swatch - Heater 20
l35B 1G 2J G + lgnrtron Switch - Heater 27
Drpped Beam 214
3
2J G Marn Beam 215
H 4
D 3 v R/H Side Lamp 202
4 J M 5J R
Earth Heater Eart; 24
11 I-203 216
5 V BI 6 J BI Heater Earth 31
R/H Direction lndrcator 112
I408 1 Heated Rear Screen IV 1 0 J 1 BI
162 Main Beam 215
2 2 Heated Rear Screen 2 J V
163 Dipped Beam 213
3 s Boot Lighting 3 G
188 Rear Fog Lamp Swatch
208
4 Side Lamps 4G N
217 + Directron Indicator Swatch 108
5 5
Rear No Plate Lamps 219
B 5 G BI L/H Drrection lndrcator I 109
R 6 2
Stop Lamps 6 G M Earth
147 I105
E 7G R Side Lamps
7 3 L/H DIrectron lndrcator 109 211
8 L? R/H Drrectron Indicator 8G B
110 R/H Directron lndrcator 110
9 t” Reversing Lamps 33 9 J N + Direct Lrghtrng 201
0 Rear Fog Lamps 208 0 BI N + Drrect Lrghting 201
IllOM 1 IV24M 1 + Battery lgnttron Switch 138
2J G Marn Beam 216 2 + Battery lgnrtron Swatch 27
3 3 + Battery lgnttion Switch 5
4 * 4 + Battery - lgnitron Swatch 38
56 R Side Lamps 211 .
B 6 IV31N 1 Heated Rear Screen
7M V Hand Brake 90 I.
8 N + Ignition Switch 79 IV46J 1 J R Windscreen Wiper Fast Speed 133
9V N + Direct 68 2 J Mv Wrndsc Wtper t lgnrt Swatch 138
0 V BI Tachometer 65 3 G Mv Windscreen Washer Pump
B 138
4 J BI Wrndscreen Wiper Slow Speed 134
II288 1 Side Lamp 204 5G v Windscreen Wiper Parkrng 136
2 B G Hazard Warning Switch 111 .6 G J Windscreen Wiper Timer 135
3B N + Drrect 110 .
B 4 B BI L/H Direction Indicator 111
IV 5 7 B 1 G Mv Windscreen Washer Pump 138
5 6 Mv + lgnitron Switch 111
2 G M Earth 6-80 138
6B J + Drrection Indicator Unit 107
3J G Earth
7 0 160
R/H Direction Indicator 112
G 4 M Cooling Fan Relay 6 a M Earth 113
5G B Horn 159
6 BI Cooling Fan 7
ll32B 1 V Cigar Lrghter Lighting 203 7V J
H 2 + lgnitron Cooling Fan Relay 6
II43M 1 J V13J 1
Earth 94
2 J 2 B V Horn
Earth 93
B 159
MB 3 B M
3 J Earth + Horn
92 159
II538 1 V J Rear View Mtrror De-lcrng V 2 4 BI 1 BI
158 Rear Window Motor
116
2v B Heated Rear Screen Switch 2J V
162 Height Corrector Earth 141
H H 3 V Mv + Ignition Switch 3J N + Drrect height Corrector 144
4J B + lgnrtron herght Corrector 139
(Heated Rear Screen) 162
lll12M 1 J Earth 204 189 V32N IN + Battery Junction Box 2
H J N + Crgar Lighter 90 G N + Battery Junctron Box 2
Ill 2 6 M 1 G N + Stop Lamp Switch 147 V45J 1 J R Wrndscreen Wrper Fast Speed 133
2 G M Earth 90 2 J BI Windscreen Wiper Slow Speed 134
3
D 3 G B Windscreen Wrper Parking 136
H 4V R + Glove Box Lrghting 187 4J N + lgnitron Windscreen Wiper 137
5 G Stop Lamp Switch 147 5 J Earth Windscreen Wiper 134
6 V Hand Brake Swatch 90
V54J IJ R Starter Solenord 5
III 3 2 N 1 V R + Direct Radro 191 2 G Bi Reversrng Lamps 33
H 2 ( + lgnrtion Swrtchl G 3 G + lgnrtron Swatch After Fl 34
4G R + lgnrtron Swatch Rev Switch 33
lll44B 1 lgnttron Swatch + C iF3) 138 -
2 lgnrtron Switch + C tF2) 27 V 6 3 R 1 BI N Rear Wrndow Motor 128
3 Starter Swatch 5
H 2G R t Direct After F7 179
4 lgnrtion Switch -t C lgnrtron 38 3J M + Dtrect Rear Crgar Lrgther 139

Connectors
l.-~l
a,
- Connectors
,”
9 r, 75 Colour
FiY
E
vl
-
M
M
V
V
V
V
M
M
-
N
v
V
M
N
V
-
V
M
V
V
V
-
M
V
2
$
R
V
M
Mv
B
N
BI
B
Mv . -
z
Y
i
r”
B
G Function Function
:
m
.e-
1
-
1
2
3
-
1
2
3
4
1
2
3
4
I
2
3
4
-
1 .-
f
-
M
M
M
-
N
N
M
-
B
B
V
G
N
-
N
M
-
V
V
-
-
M 1
2
3
-
-
-
-
1
2 -
3 -
6 -
4 -
4 -
4 -
3
1
3
-
9
-
6
-
9
-
2
L.
B
-
J
-
v
-
V
-
B
m
sg
ZD
‘N
B
-
B
-
B
-
B
-
V
-
-
-
B Eng. Oil Pressure Sensor
94
95
96 Choke
Diesel Pre Heating
Front Bulb Failure 84
I 8
1
Eng. Oil Sensor
V
J
J Low Fuel Warning Lamp
Fuel Gauge
Fuel Transmitter Earth “Stop” Warning
Hydraulic Warning
Eng. Oil Low Pressure Warning
Water Low Level Warning
Water Temp. Warning
” + Ignition Switch
Battery Charge Warning
Eng. Oil Temp. Warning
Water Low Temp. Warning
2 74
80
79
77
73
80
89
70
100
102
101
98
99
97
85
90
211
212
214
103
103
9
10
11 Instrument Lighting
L/H Dir. Ind. Warning
Seat Belt Warning
+ Ignition Switch (After F2)
Earth 107
R/H Dir. Ind. Warning 105
106
85
211
108
65
66
65 BI
Mv
M
B
Mv
3
L/H Rear Door Warning
Boot Door Warning
R/H Rear Door Warning
L/H Front Door Warning
R/H Front Door Warning
Bonnet Door Warning + Ignition Switch (After F.2)
Earth
Diesel TDC
Tachometer
4
B
G Turbo Pres. Warning
Anti-knock Warning 64
63
Yelow Warning
Red Warning econoscope
5
Brake Pad Wear Warning
Hand Brake Warning
Rear Fog Lamp Warning
Side Lamp Warning
Dipped Beam Warning
Main Beam Warning
Clogged Filter Warning
0 ic 6
R Earth
Test
Warning Rear Bulb
Failure
Unit 81
82
83
7
12 ?ABS Warning
+ Ignition Switch ABS

2 MA LOCATION OF THE ELECTRONIC CONTROL
510.00/3
UNITS AND RELAYS (All Models)
POSITIONING OF THE ELECTRONIC CONTROL UNITS AND RELAYS
No. Description Location
54 ABS Control Unit G
57 Fuel Calculator Unit A
60 Air Conditioning Control Unit A
76 Window Winder Unit F
80 Speed Regulating Unit E 81
Heater Control Unit A
84 Water Level Unit L
87 Water Temperature Unit B
89 Door Locking Warning Unit A
90 Door Lock Control Unit A 91
Remote Control door Lock Unit C
92 Interior Lighting Timer A
93 Bulb Failure Indicator Unit (Salopn) H
93 Bulb Failure Indicator Unit (Safari) J 110
Heater Plug Control Unit
,. K 127
Side lamp Audible Warning D 141
Ignition ECU K 142
Injection ECU E 151
Water temperature Flasher unit B 658
Blower Speed Control Unit E 731
Fuel Injection electronic Relay M 733
Air Cond. Engine Fan Relay K 734
Injector relay M 735
Main Beam Relay D
739 Height Control relay B 743
Air Horn Compressor Relay K 745
Blower Motor Fast Speed Relay A 750
Fog Lamp Relay
6 756
ABS Electra-Valve Relay L 757
ABS Protection Relay L 772
Blower Fan Motor 2nd Speed Relay K 773
Engine Cooling Fan lnverter Relay K 775
Starter Motor Safety Relay (Auto G/Box) B 778
Fuel Heater/Starter Motor Relay (with diode) K
779 Fuel Heater Oil pressure Relay (with diode) K 781
Main fuel Heater Relay K RI
Engine Cooling Fan Relay B R2
Front Window Winder Relay 6 R3
Rear Window Winder Relay B R4
Heated Rear Screen Relay 6 I
Windscreen Wiper Timer Relay
B
C Direction Indicator Unit B

ARRANGEMENT OF THE ELECTRICAL INSTALLATION
q @ CX22TRS 7/85-t 1 MA 5 510.00110
3EF. DESCRIPTION LOCATION
Circuit Wiring CONNECTOR
Number HARNESS
Channel-colour (or urilt)
1 Front cigar ljghter & lighting 137-151
i5 38-l v H
5 Ignition distributor 30 to 34 3N 2
10 Alternator 51 to 54 b6 IN + Ilc CA & M
25 A & B Horn 107 - 108 c7 1N + 1N A
45 Battery 1
b8 IN + IN CP & CN
46 Instrument panel 36 to 73 159 to 162 g6 * T
50 Ignition coil 30-3 1 IN + Ilc G
75 Ignition module 30 to 32 7N Z
81 Interior heating control unit 21 to 24 h5 8N K
84 Coolant level indicator unit 41 to 43 e4 5B D
89 Door locking indicator lamp unit 131-132
i5 5N H
90 Door locking control unit 124 to 134 15 9v H
91 Remote control door locking unit “PLIP” 120 to 122 n5 8N P
92 Interior lamp timer 117 to 122 15 7M H
93 Bulb failure detection unit
27, 46 to 48, 74-75, 104-I 65 S8 38 + 68 & 6J L & w
95 Junction/Fuse box
127 Side lamp audible warning 1222123 g8
g6 5+N‘” ;
130 TDC sensor 28 3M
170 Boot light switch 136 s6 IM E
174 Boot door locking switch 126 t5 2M C
180 Reversing lamp switch 27 d6 1N + 1V G
185 Stop lamp switch 104 h6 IN + IM H
190 Hand brake switch 55 k5 2M H
!25 Carburettor choke switch 49 IG B
!29 Ignition switch 4-30, 44-95 h7 4M + 48 (95)
!30 L/H Front door switch *
119 f9 IM H
!31 R/H Front door switch 120 fl 1M H
!32 L/H rear door switch 122
k9 IM H
!33 R/H Rear door switch 123 kl IM H
!34 Glove box switch 135 f3 1 Ic+ 1 Ic H
!35 Hydraulic fluid low pressure switch 46 e6 IM G
!36 Hydraulic fluid level switch 45 e8 1 Ic + IM G
!37 Coolant low level switch 41-42 e3 3R D
!38 R/H Front door lock switch 64
jl 28 H
!39 L/H Front door lock switch 63 P
28 H
!41 R/H Rear door lock switch 66 (71 28 PD !42 L/H rear door lock switch 65 qg 28 PG
!43 Boot door lock switch 67 c5 2M C
!44 Bonnet lock switch 62 a5 2M V
!51 Height control switch 96 to 100
j5 2M & 4M H & (608) !54 Lighting/Direction indicator switch 72 to 75. 57 to 163 97 58 4M 3M T
!55 Windscreen wiper/Washer & Horn switch 90 to 95, 107 g6 48 5B 28 T
!68 Air recycling switch 15 to 17
h5 4J Q
!71 Air distribution switch 12 to 14 h5 4M Q !78 Blower motor speed control 18 to 20 h6 38 Q
!79 Heater control & Lighting 23 to 25-68 h4 58 K
100 Starter motor 2 to 4 b5 IN & IR CP 165 Ashtray lighting 152 if5 2B H
I70 Boot lighting 136 s4 1N & llc F
I75 Glove box lighting 135 f4 IN & 1M H I80 Engine compartment lighting 150 c6 IN EC
I85 L/H rear number plate lighting 166 t6 Ilc + IM E 186 R/H rear number plate lighting 167 t4 Ilc + IM E
190 Steering lock lighting 156 97 Ilc + IIC T
L20 Carburettor idle cut-out solenoid 25 IN M L30 L/H front brake caliper 48-49 d9 2N + IN U(g.) I31 R/H front brake caliper 50-51 dl 2N + IN U(d.!
L40 L/H front side lamp 149 a8 2M G
141 R/H front side lamp 151 a2 2M D 142 L/H rear lamp 165 L43 R/H rear lamp 166 I45 L/H rear lamp cluster t8 6G F
146 R/H rear lamp cluster t2 6G F
157 L/H stop lamp 104
* Particular Specification
8531-8532