1994 JAGUAR XJ6 ABS

15.3.5 PIN-POINT TESTS
The following tests give detailed information on component fault diagnosis.
1. Power supply
a. Check fuse FIO in LH 'A' post base fuse-box is intact.
b. Unplug harness connector from SCCM and check for battery supply voltage to ground, at pins 1 and 2
with ignition on. If supply is not recorded on either pin switch off ignition and check harness wiring
continuity from LH
'A' post base fuse-box to splice FCS16.
If supply is recorded at pin 1 only check brake and clutch (where fitted) switch contacts (closed when
pedals not operated). For vehicles with automatic transmission ensure clutch pedal switch link is
correctly fitted. Examine harness wiring and check continuity between pin
2 and splice FCS16.
If supply is recorded at pin 2 only examine harness wiring and check continuity from pin 1 to splice
FCS
16.
c.
d.
m
P1I
1
k wv I wu I
I-------
*+12V Present Only When Ignition ON
1. Speed Control Control Module (SC CM) 7. Dump Valve
2. Clutch Switch / Link 8. Control Valve / Pump Unit
3. Brake Switch
9. Gear Position Module 4. LH 'A' Post Base Fuse-box 10. ABS Control Module 5. Switch Pack 11. Instrument Pack
6. Column Switchgear Dimmer
Fig. 1 Speed Control Power Supply
Issue 1 August 1994 X300 EDM 15.3 - 7

n Electrical
2. Switch pack assembly
a. Unplug switch pack connector and check for battery voltage between pin 4 and ground with
ignition
off. If battery voltage is not present, switch ignition off and examine wiring harness,
checking continuity between pin
4 and splice FCS16.
b. Test operation of switches between pins as follows:
ON: Normally open; closes on operation completing circuit between pins
4 and 5 and pins 1
and 5. A resistance of less than IQ should be recorded when testing pins 4 and 5.
Minimal resistance should be recorded when testing pins 1 and 5.
SET: Normally open; closes on operation completing circuit between pins 2 and 5.
A resistance of approximately 100Q should be recorded.
RES: Normally open; closes on operation completing circuit between pins
2 and 5.
A resistance of approximately 330Q should be recorded.
c. Examine wiring harness and check continuity between pin
5 and ground.
Ptl
PI1
1
m) su
I U0
I
*+12V Present Only When Ignition ON
1. Speed Control Control Module (SC CM)
7. Dump Valve 2. Clutch Switch I Link 8. Control Valve / Pump Unit 3. Brake Switch 9. Gear Position Module
4. LH ‘A’ Post Base Fuse-box 10. ABS Control Module
5. Switch Pack 11. Instrument Pack
6. Column Switchgear Dimmer
Fig. 1 Speed Control Switches
0
0
0
0
Issue 1 August 1994 15.3 - 8 X300 EDM

E I ect r ica I n
3. Brakeswitches
a. Unplug switch connector and check for battery voltage between pin 3 and ground with ignition
b.
on. If battery voltage is not present switch off ignition and examine harness, checking
continuity between pin 3 and splice
FCS16.
Test switch continuity across pins as follows:
Pin
3 - Pin 2; normally closed, opens on pedal operation breaking circuit continuity. Also,
checkcontinuity from pin
2 to clutch switch (where fitted) or link pin 1.
Pin 1
- Pin 4; normally open, closes on pedal operation completing circuit continuity. Also,
check continuity from switch pin 1 to
SC CM pin 15 and switch pin 4 to ground.
4. Clutch switch (where fitted) or link
a. Unplug switch connector and check for battery voltage between pin 1 and ground with ignition
on. If battery voltage is not present switch
off ignition and examine harness, checking continuity
between pin 1 and splice
FCS16.
Check continuity across switch pins 1 and 2, switch (where fitted) is normally closed and opens
on pedal operation.
Examine wiring harness, checking continuity between pin
2 and SC CM pin 12.
b.
C.
1
.---I
1. Speed Control Control Module (SC CM) 7. Dump Valve
2. Clutch Switch 1 Link 8. Control Valve / Pump Unit
3. Brake Switch 9. Gear Position Module 4. LH 'A' Post Base Fuse-box 10. ABS Control Module
5. Switch Pack 11. Instrument Pack
6. Column Switchgear Dimmer
Fig. 1 Brake and Clutch Switches
X300 EDM 15.3 - 9 Issue 1 August 1994

rl E I ect r ica I
5. Dump valve
a.
b.
Unplug connector from valve and test continuity across solenoid (pins 1 and 2). A resistance value of
approximately 4052 should be recorded.
Examine harness wiring, checking continuity between valve pins 1 and
2 and SC CM pins 4 and
3 respectively.
6. Control valve / pump unit
a. Unplug connector from unit and test continuity across valve solenoid (pins 3 and 2). A
resistance value of approximately 8552 should be recorded.
b. Test continuity across pump motor (pins 3 and 1, refer to Fig 1). A resistance value of approx.
2052 should be recorded.
c. Examine harness wiring, checking continuity between unit pins 1,2 and 3 and SC
CM
pins 20, 10 and 3 respectively.
I Ii
1
1. Speed Control Control Module (SC CM) 7. Dumpvalve
2. Clutch Switch / Link 8. Control Valve / Pump Unit
3. Brake Switch 9. Gear Position Module
4. LH 'A' Post Base Fuse-box 10. ABS Control Module
5. Switch Pack
11. Instrument Pack 6. Column Switchgear Dimmer
Fig. 1 Dump Valve and Control Valve
/ Pump Unit
0
0
0
0
Issue 1 August 1994 15.3 - 10 X300 EDM

7. Gear position input
a. Examine harness wiring, checking continuity between SC CM pin 18 and transmission decoder module
(6 cylinder) or linear switch (12 cylinder)
b. Examine transmission fault diagnosis.
8. Road speed input
a. Examine harness wiring, checking continuity between SC CM pin 6 and instrument pack.
b. Examine instrument pack fault diagnosis.
9. Traction control input
a.
b.
Examine harness wiring, checking continuity between SC CM pin 9 and ABS TC J CM.
Examine ABS TC
J CM fault diagnosis.
1
1. Speed Control Control Module (SC CM) 7. Dump Valve
2. Clutch Switch J Link 8. Control Valve / Pump Unit
3. Brake Switch
9. Gear Position Module 4. LH 'A' Post Base Fuse-box 10. ABS Control Module
5. Switch Pack 11. Instrument Pack 6. Column Switchgear Dimmer
Fig. 1 Gear Position, Road Speed and Traction Control Inputs
Issue 1 August 1994 15.3 - 11 X300 EDM

A E C D E F
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X300 EDM Issue 1 August 1994

Circuit Diagrams
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Issue I August 1994 page 16 I X300 EDM

Circuit Diagrams
I I I I A I I I J I K D E F G H A E C Rb NO FBHLH DEC 1157 ,____________.
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X300 EDM page 32 Issue 1 August 1994