1998 JAGUAR X308 speed

Connect the scan tool 1
Have the DTC(s) and freeze frame data been recorded?
Yes GO to D2
D2: CHECK FOR LOW EXHAUST TEMPERATURE
Check the engine and exhaust system for correct operation
and normal running temperature 1
Is the engine and exhaust system operating correctly and up to
normal running temperature?
Yes GO to D3
No Rectify leaking exhaust manifold / catalyst, general causes of
an over rich mixture and engine cooling system operation
and test the system for correct operation.
GO to D7
D3: CHECK FOR O2 SENSOR FAILURE
Run the engine for a period to warm the sensor and then
maintain a steady speed of approximately 2500 rpm. 1
Measure the voltage between EM022/001 and EM022/002. 2

Run the engine for a period to warm the sensor and then
maintain a steady speed of approximately 2500 rpm. 1
With EM023 disconnected, measure the voltage between
EM023/003 and EM023/004. 2
Is the voltage between 600mV and 1.0 Volt?
Yes
GO to E4
No Renew O2 sensor. Reconnect plug(s)
GO to E7
E4: CHECK FOR O2 SENSOR FAILURE

Run the engine for a period to warm the sensor and then
maintain a steady speed of approximately 2500 rpm. 1
Measure the voltage between EM023/003 and
EM023/004. 2
Is the voltage between 600mV and 1.0 Volt?
Yes
GO to F5
No Renew O2 sensor. Reconnect plug(s).
GO to F8
F5: CHECK FOR O2 SENSOR FAILURE
With the conditions held as F4, suddenly decelerate to
idle. 1
Has the voltage dropped to 400mV or less ?
Yes GO to F6
No Renew O2 sensor. Reconnect plug(s)
GO to F8
F6: CHECK FOR O2 SENSOR FAILURE
With the conditions held as F5, suddenly accelerate to
approximately 2500 rpm. 1
Has the voltage risen to between 600mV and 1 volt?

Connect the scan tool 1
Have the DTC(s) and freeze frame data been recorded?
Yes GO to G2
G2: CHECK FOR O2 SENSOR FAILURE
Run the engine for a period to warm the sensor and then
maintain a steady speed of approximately 2500 rpm. 1
Measure the voltage between EM024/001 and EM024/002. 2
Is the voltage between 600mV and 1.0 Volt?
Yes
GO to G3
No Renew O2 sensor and reconnect plug(s)
GO to G6
G3: CHECK FOR O2 SENSOR FAILURE

Conne
ct the scan tool
1
Have the DTC(s) and fr

eeze
frame data been recorded?
Yes GO to H2
H2: CHECK
FOR LOW EXHAUST TEMPERATURE
Chec

k the engine and exhaust
system for correct operation
and normal running temperature
1
Is th
e engine and exhaust system operating correctly and up to
normal running temperature?
Yes GO to H3
No Rectify leaking exhaust manifold / catalyst, general causes of
an over rich mixture and engine cooling system operation and
test the system for correct operation.
GO to H7
H
3: CHECK FOR O2 SENSOR FAILURE
I

gnition switch to position 0
1
Di

sconnect EM024
Bracket on top o

f gearbox or
Bulkhead rear of engine
2
R
un the engine for a period to
warm the sensor and then
maintain a steady speed of approximately 2500 rpm.
3
W
ith EM024 disconnected, measure the voltage between
EM024/001 and EM024/002.
4
Is
the voltage between 600mV and 1.0 Volt?
Yes GO to H4
No Renew O2 sensor. Reconnect plug(s).
GO to H7
H
4: CHECK FOR O2 SENSOR FAILURE

Speed Control - Speed
Control
D
iagn
osis and Testing
Pri
n
ciples of operation
The s
p
eed (cruise) control sy
stem is activated by an ON/OFF master switch in the J-gate surround, which has an integral
LED to indicate status.
The steering wheel switches allow the driver to set the speed, increase or decrease the selected speed, cancel and resume
the facility without his/her hand ever leaving the steering wheel
The vehicle speed can be increased an d decreased in increments of 2 kmh (1 mph) by briefly pressing the + or - buttons up
to a maximum of five times.
Alternatively, the + or - button can be held until th e desired speed is reached.
The selected speed (by whichever method) w ill be displayed in the message center.
The system will not function at speeds below 26 kmh (16 mph), and can be cancelled from the master switch, the steering
wheel switches, and by depressing th e brake pedal. The system can be overridden by accelerating as normal.
In
spection and Verification
1.
1. Veri fy the customer concern.
2. 2. Vis
ually inspect for obvious signs of mechanical or electrical damage.
3. 3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding
to the next step.
4. 4. If the cause is not visually evident, verify the symptom, check for DTCs and follow the routines in this section.
Vi
sual Inspection Chart
Diagnostic Trouble Code (D
TC) index
MechanicalElectrical
Throttle body mechan
ism
Throttle body actuator
Module Switch(es) Instrument cluster
DTC

De
scr
iption
Possib
l
e Source
Acti
o
n
P0566Speed
c
ontrol
CANCEL
switch ON fault
Speed
control switches internal steering wheel
short circuit to ground
St
eering wheel cassette reel short circuit to
ground
Cassette reel to ECM circ
uit short circuit to
ground
CANCEL
switch failure (stuck ON)
Fo
r

CANCEL switch circuit
tests,GO to Pinpoint Test A.
P0567Speed c
ontrol
RESUME
switch ON fault
Speed
control switches internal steering wheel
short circuit to ground
St
eering wheel cassette reel short circuit to
ground
Cassette reel to ECM circ
uit short circuit to
ground
RESUME swit
ch failure (stuck ON)
For

RESUME switch circuit
tests,GO to Pinpoint Test B.
P0568Spee
d control switch
ground malfunction
Speed
control switches internal steering wheel
open circuit
St
eering wheel cassette reel open circuit or
high resistance
Cassette reel to ECM ci
rcuit open circuit or high

For

ACCEL/DECEL switch circuit
tests,GO to Pinpoint Test C.

Pinpoint test
s
re
sistance
ACCEL/DECEL
swi
tch failure
P0569Speed

control
DECEL/SET
(SET-) switch ON fault
Speed
control switches internal steering wheel
short circuit to ground
S
teering wheel cassette
reel short circuit to
ground
Cassette reel
to ECM ci
rcuit short circuit to
ground
DEC
EL/SET
switch failure (stuck ON)
Fo
r
DECEL/SET (SET-) switch
circuit tests,GO to Pinpoint Test D.
P0570Speed
control
ACCEL/SET
(SET+) switch ON fault
Speed
control switches internal steering wheel
short circuit to ground
S
teering wheel cassette
reel short circuit to
ground
Cassette reel
to ECM ci
rcuit short circuit to
ground
ACC
EL/SET
switch failure (stuck ON)
Fo
r
ACCEL/SET circuit tests,GO
to Pinpoint Test E.
P1571Brake sw
itch malfunction
Brake sw
itch to ECM circuit open circuit, short
circuit to ground, high resistance
Brake sw
itch ignition switched ground circuit
open circuit
Brake sw
itch failure
Brake ca

ncel switch to
ECM circuit open circuit,
short circuit to ground, high resistance
Brake ca
ncel switch to speed control switch
circuit open circuit, shor t circuit to ground, high
resistance
Brake ca
ncel switch ignition switched power
supply open circuit
Brake ca
ncel switch failure
Spe

ed control switch failure
For brake swi
tch circuit tests,GO
to Pinpoint Test F.
P
INPOINT TEST A : DTC P0566; SPEED
CONTROL CANCEL SWITCH ON FAULT
WAR
NING: Where tests involve the removal of the steering
wheel, and/or disconnection of air bag connectors, the
procedure for disarming air bags must be followed,
REFER to: Air Bag Supplemental Re straint System (SRS)

(501-20B Supplemental Restra
int System, Description and
Operation).
TE
ST
CONDITIONS
D
ETAILS/RESULTS/ACTIONS
A1: CHECK

THE SPEED CONTROL SWITCHPACK IN
TERNAL CIRCUITS FOR SHORT TO GROUND
Di
sconnect the battery negative terminal.
1
Di

sconnect the speed control switch
pack electrical connector, SW02.
2
R
econnect the battery negative terminal.
3
Meas

ure the resistance between SW
02, pin 06 (BO) and GROUND.
4
Meas
ure the resistance between SW
02, pin 03 (SG) and GROUND.
5
Is either resi
stance
less than 10,000 ohms?
Yes REPAIR the short circuit. For addi tional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.
No GO to A2
.
A2: CHECK
THE SPEED CONTROL CASSE
TTE REEL FOR SHORT TO GROUND
Di
sconnect the battery negative terminal.
1
D

isconnect the ECM electrical connector, EM11.
2
R

econnect the battery negative terminal.
3
M

easure the resistance between SW02, pin 06 (at the cassette reel side of the connector) and
GROUND.
4
M
easure the resistance between SW02, pin 03 (at the cassette reel side of the connector) and
GROUND.
5
Is either resi
stance
less than 10,000 ohms?
Yes REPAIR the short circuit. For addi tional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.

No
GO to A3.
A3: CHECK THE SPEED CONTRO L CANCEL SWITCH
ACTION
Meas
ure t
he resistance between SW02,
pin 06 (BO) and SW02, pin 03 (SG).
1
Operate
the speed control
CANCEL switch.
2
Do
es the resistance
vary by 680 ohms?
Yes Recheck DTCs. No short found. Po ssible intermittent fault. CLEAR the DTC. TEST the system for
normal operation.
No INSTALL a new speed control switchpack. CLEAR the DTC. TEST the system for normal operation.
PINPOINT TEST B : DTC
P0567; SPEED
CONTROL RESUME SWITCH ON FAULT
WARN
ING: Where tests involve the removal of the steering
wheel, and/or disconnection of air bag connectors, the
procedure for disarming air bags must be followed,
REFER to: Air Bag Supplemental Re straint System (SRS)
(50
1-20B Supplemental Restra
int System, Description and
Operation).
TE S
T
CONDITIONS
D E
TAILS/RESULTS/ACTIONS
B1: CHECK
THE SPEED CONTR
OL SWITCHPACK IN
TERNAL CIRCUITS FOR SHORT TO GROUND
Disc
onnect the speed control switch
pack electrical connector, SW02.
1
Measure t
he resistance between SW
02, pin 06 (BO) and GROUND.
2
Measure t
he resistance between SW
02, pin 03 (SG) and GROUND.
3
Is either resistance le
ss than 10,000 ohms?
Yes REPAIR the short circuit. For addi tional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.
No GO to B2
.
B2: CHECK THE SPEED CONTR
OL CASSETTE REEL FOR SHORT TO GROUND
M
e
asure the resistance between SW02, pin 06 (at the cassette reel side of the connector) and
GROUND.
1
Me
asure the resistance between SW02, pin 03 (at the cassette reel side of the connector) and
GROUND.
2
Is either resistance le
ss than 10,000 ohms?
Yes REPAIR the short circuit. For addi tional information, refer to the wiring diagrams. CLEAR the DTC.
TEST the system for normal operation.
No GO to B3
.
B3: CHECK THE SPEED CONTR
OL RESUME SWITCH ACTION
Meas
ure t
he resistance between SW02,
pin 06 (BO) and SW02, pin 03 (SG).
1
Operate
the speed control
RESUME switch.
2
Do
es the resistance
vary by 430 ohms?
Yes Recheck DTCs. No short found. Po ssible intermittent fault. CLEAR the DTC. TEST the system for
normal operation.
No INSTALL a new speed control switchpack. CLEAR the DTC. TEST the system for normal operation.
PINPOINT TES
T C : DTC P0568; SPEED CONTROL SWITCH GROUND MALFUNCTION
WAR
N
ING: Where tests involve the removal of the steering
wheel, and/or disconnection of air bag connectors, the
procedure for disarming air bags must be followed,
REFER to: Air Bag Supplemental Re straint System (SRS)

(50
1-20B Supplemental Restra
int System, Description and
Operation).
TE S
T
CONDITIONS
D E
TAILS/RESULTS/ACTIONS
C1: CHECK FOR CONTINUITY T
H
ROUGH STEERING WHEEL
CANCEL AND RESUME SWITCHES (SWITCHES OPEN)
Disc
onnect the speed control switch
pack electrical connector, SW02.
1
Check for c
ontinuity between SW02
, pins 06 (BO) and 03 (SG) wi th the steering wheel switches
inactive.
2