1999 LAND ROVER DISCOVERY check engine

AUTOMATIC GEARBOX - ZF4HP22 - 24
DESCRIPTION AND OPERATION 44-19
Fault effects and warning indications
Fault code,
OBD II
(TestBook)Fault description Effect Warning lamp
illumination
MIL Sport/
Manual
P0705
(14, 23)* Gear position switch,
incorrect outputsMaintains current gear in low range, limp
home mode in high range. Shift pressure to
maximum, harsh gear shifts/engagement.On On
P0721
(21)* Downshift safety
monitor prevented
downshift which would
have caused engine
overspeedMaintains current gear in low range, limp
home mode in high range. Shift pressure to
maximum, harsh gear shifts/engagement.On On
P0722
(22)* Torque converter
slippingMaintains current gear in low range, limp
home mode in high range. Shift pressure to
maximum, harsh gear shifts/engagement.On On
P0731
(29)* Ratio monitoring,
implausible 1st gear
ratioNo apparent effect On On
P0732
(30)* Ratio monitoring,
implausible 2nd gear
ratioNo apparent effect On Off
P0733
(31)* Ratio monitoring,
implausible 3rd gear
ratioNo apparent effect On Off
P0734
(32)* Ratio monitoring,
implausible 4th gear
ratioNo apparent effect On Off
P0741
(5)* Torque converter
lock-up clutch faultMay affect driveability. On Off
P0743
(7, 25)* Torque converter
lock-up solenoid (MV
3), open or short circuitLimp home mode in low and high ranges. Shift
pressure to maximum, harsh gear shifts/
engagement.On On
P0748
(10, 28)* Pressure regulating
solenoid (MV 4), open
or short circuitLimp home mode in low and high ranges. Shift
pressure to maximum, harsh gear shifts/
engagement.On On
P0753
(8, 26)* Shift solenoid (MV 1),
open or short circuitLimp home mode in low and high ranges. Shift
pressure to maximum, harsh gear shifts/
engagement.On On
P0758
(9, 27)* Shift solenoid (MV 2),
open or short circuitLimp home mode in low and high ranges. Shift
pressure to maximum, harsh gear shifts/
engagement.On On
P1562
(24)* Battery supply below
9V while engine
runningMaintains current gear in low range, limp
home mode in range. Shift pressure to
maximum, harsh gear shifts/engagement.Off On
P1601
(4)* ECU, EEPROM
checksumLimp home mode in low and high ranges. Shift
pressure to maximum, harsh gear shifts/
engagement.On On
P1606
(3)* EEPROM No apparent effect On†Off
P1606
(6)* Watchdog No apparent effect On On
P1612
(2)* Solenoid valves
power supply relay,
sticking closed or open
circuitLimp home mode in low and high ranges. Shift
pressure to maximum, harsh gear shifts/
engagement.On On

AUTOMATIC GEARBOX - ZF4HP22 - 24
44-20 DESCRIPTION AND OPERATION
P1613
(1)* Solenoid valves
power supply relay,
sticking open or short
circuitLimp home mode in low and high ranges. Shift
pressure to maximum, harsh gear shifts/
engagement.On On
P1705
(39)Transmission high/low
range, implausible
inputNo apparent effect On Off
P1810
(12, 13)Sport/Manual warning
lamp circuit faultLamp fails bulb check or is permanently
illuminated. No effect on gearbox operation.On Off
P1841
(16)* CAN bus fault Maintains current gear in low range, limp
home mode in high range. Shift pressure to
maximum, harsh gear shifts/engagement.On On
P1842
(15)* CAN level monitoring Maintains current gear in low range, limp
home mode in range. Shift pressure to
maximum, harsh gear shifts/engagement.On On
P1843
(17)* CAN time-out
monitoringMaintains current gear in low range, limp
home mode in high range. Shift pressure to
maximum, harsh gear shifts/engagement.On On
P1884
(11)* CAN message:
Engine friction invalidNo apparent effect. On Off
P1884
(18)* CAN message:
Throttle position invalidSubstitute throttle angle of 50% adopted. No
kickdown. Operates in economy modes only.On On
P1884
(19)CAN message: Engine
temperature invalidSubstitute engine temperature derived from
other inputs. No apparent effect.On Off
P1884
(20)CAN message: Road
speed invalidNo apparent effect On Off
P1884
(33, 34)* CAN message:
Engine torque invalidSubstitute engine torque of derived from other
inputs. May affect shift quality.On Off
P1884
(35)* CAN message:
Engine speed invalidMaintains current gear in low range, limp
home mode in high range. Shift pressure to
maximum, harsh gear shifts/engagement.On On
P1884
(37)CAN message: Engine
air intake temperature
invalidNo apparent effect. On Off
P1844
(38)Altitude shift control
invalidNo reduced torque compensation, possible
reduction in performance/ driveability at
altitude or high ambient temperatures.On Off
* = Emissions (OBD II) relevant
†On = MIL illuminates immediately (in all other faults, MIL On = illuminates in the 2nd consecutive drive cycle if
fault still present)Fault code,
OBD II
(TestBook)Fault description Effect Warning lamp
illumination
MIL Sport/
Manual

AUTOMATIC GEARBOX - ZF4HP22 - 24
ADJUSTMENTS 44-21
ADJUST ME NTS
Cable - selector
$% 44.30.04
Check
1.Position vehicle on ramp.
2.Select position 'P'.
3.Loosen selector cable trunnion nut.
4.Ensure that gearbox selector lever is in 'P'
position, (fully forward) and tighten trunnion
nut.
5.Lower ramp.
Stall test
$% 44.30.13
Testing
1.Chock the wheels and fully apply the
handbrake.
2.Start the engine and run it until it reaches
normal operating temperature.
3.Apply the footbrake and select 'D'.
4.Fully depress the accelerator pedal and note
the tachometer reading. The figures should be
as given below. Do not carry out stall test for
longer than 10 seconds, and DO NOT repeat
until 30 minutes have elapsed.
lV8: 2200 to 2400 rev/min
lDiesel: 2600 to 2800 rev/min
5.A reading below 1300 rev/min indicates a
torque converter fault, ie stator free-wheel.
6.A reading between 1300 and 2200 rev/min (V8)
or between 1300 and 2600 rev/min (Diesel)
indicates reduced engine power.
7.A reading above 2400 rev/min (V8) or above
2800 rev/min (Diesel) indicates clutch slip.
NOTE: The figures quoted above were
measured at sea level with an ambient
temperature of 20
°C (68°F). At higher altitudes
or higher ambient temperatures, these figures
will be reduced.

AUTOMATIC GEARBOX - ZF4HP22 - 24
REPAIRS 44-31
40.Fit suitable strap to retain torque converter.
Refit
1.Clean gearbox to engine mating faces.
2.Remove torque converter retaining strap.
3.With assistance position gearbox to engine.
4.Fit but do not tighten six bolts securing gearbox
housing to engine.
5.Connect multiplug to gearbox and tighten
locking ring.
6.Connect multiplug to inhibitor switch.
7. If fitted: Connect and adjust differential lock
selector cable.

+ TRANSFER BOX - LT230SE,
ADJUSTMENTS, Cable - selector -
differential lock - adjust.
8.Position selector lever to inhibitor switch and
tighten nut to 25 Nm (18 lbf.ft).
9.Position selector cable to gearbox and secure
with 'C' clip.
10.Clean oil pipe unions and fit new 'O' rings.
11.Position and tighten pipe unions to gearbox.
12.Position and tighten oil cooler pipe clamps.
13.Position and tighten oil cooler pipe clips to
engine sump and alternator bracket.
14.Position engine RH and LH rear mountings
and tighten bolts to 85 Nm (63 lbf.ft) and nuts to
85 Nm (63 lbf.ft).
15.Secure gearbox breather pipes to bulkhead
clip.
16. Up to 03 Model Year - If fitted: Connect 2
Lucars to differential lock warning lamp switch
and multiplugs to high/low ratio switch and
neutral sensor.
17. 03 Model Year onwards - If fitted: Connect
differential lock warning lamp switch multiplugs
to main harness.
18.Position cable tie and multiplug to transfer box
bracket.
19.Connect high/low ratio selector cable to
selector lever and secure with clevis pin. 20.Position high/low ratio selector cable to
abutment bracket and secure with 'C' clip.
21. Models fitted with high/low shift interlock
solenoid: Position interlock solenoid harness
to high/low shift cable, fit sleeve around cable
and harness.
22. Models fitted with high/low shift interlock
solenoid: Connect solenoid multiplug to main
harness and secure multiplug to bracket.
23.Position handbrake backplate and tighten bolts
to 75 Nm (55 lbf.ft).
24.Fit hand brake drum and tighten screw.
25.Remove bolts securing tool LRT-99-008A to
gearbox.
26.Rotate engine to align torque converter, fit new
bolts and tighten to 50 Nm (37 lbf.ft).
27.Fit rear propeller shaft.

+ PROPELLER SHAFTS, REPAIRS,
Propeller shaft - rear.
28.Fit front propeller shaft.

+ PROPELLER SHAFTS, REPAIRS,
Propeller shaft - front.
29.Fill transfer gearbox with oil.

+ MAINTENANCE, PROCEDURES,
Transfer box.
30.Fill automatic gearbox with oil.

+ MAINTENANCE, PROCEDURES,
Automatic gearbox.
31.Position intermediate silencer and secure to
mounting rubbers.
32.Clean silencer and tail pipe mating faces.
33.Position new gasket to tail pipe and tighten
nuts to 25 Nm (18 lbf.ft).
34.Fit exhaust front pipe.

+ MANIFOLDS AND EXHAUST
SYSTEMS - Td5, REPAIRS, Pipe - front.
35.Fit bolt securing closing plate to gearbox
housing and tighten to 7 Nm (5.2 lbf.ft).
36.Fit upper bolts securing gearbox housing to
engine and tighten to 50 Nm (37 lbf.ft).
37.Fit starter motor.

+ CHARGING AND STARTING,
REPAIRS, Starter motor - diesel.
38.Tighten remaining gearbox housing to engine
bolts to 50 Nm (37 lbf.ft).
39.Connect battery earth lead.
40.Fit battery cover and secure with fixings.
41.Check and adjust selector cable.

+ AUTOMATIC GEARBOX - ZF4HP22
- 24, ADJUSTMENTS, Cable - selector.

AUTOMATIC GEARBOX - ZF4HP22 - 24
44-36 REPAIRS
21. Models fitted with high/low shift interlock
solenoid: Position interlock solenoid harness
to high/low shift cable, fit sleeve around cable
and harness, secure sleeve.
22. Models fitted with high/low shift interlock
solenoid: Connect solenoid multiplug to main
harness and secure multiplug to bracket.
23.Position hand brake back plate and tighten
bolts to 75 Nm (55 lbf.ft).
24.Fit hand brake drum and tighten screw.
25.Remove bolts securing tool LRT-99-008A to
gearbox.
26.Rotate engine to align torque converter, fit new
bolts and tighten to 50 Nm (37 lbf.ft).
27.Fit access plug to torque converter housing.
28.Fit rear propeller shaft.

+ PROPELLER SHAFTS, REPAIRS,
Propeller shaft - rear.
29.Fit front propeller shaft.

+ PROPELLER SHAFTS, REPAIRS,
Propeller shaft - front.
30.Fill transfer gearbox with oil.

+ MAINTENANCE, PROCEDURES,
Transfer box.
31.Fill automatic gearbox with oil.

+ MAINTENANCE, PROCEDURES,
Automatic gearbox.
32.Position intermediate silencer and secure to
mounting rubbers.
33.Clean silencer and tail pipe mating faces.
34.Position new gasket to tail pipe and tighten nuts
to 40 Nm (30 lbf.ft).
35.Fit exhaust front pipe.

+ MANIFOLDS AND EXHAUST
SYSTEMS - V8, REPAIRS, Front pipe.
36.Position centre cross member, fit bolts and
tighten to 26 Nm (19 lbf.ft).
37.Connect battery earth lead.
38.Fit battery cover and secure fixings.
39.Check and adjust selector cable.

+ AUTOMATIC GEARBOX - ZF4HP22
- 24, ADJUSTMENTS, Cable - selector.

AUTOMATIC GEARBOX - ZF4HP22 - 24
REPAIRS 44-49
Cooler - fluid - Td5
$% 44.24.10
Remove
1.Remove intercooler.

+ ENGINE MANAGEMENT SYSTEM -
Td5, REPAIRS, Intercooler.
2.Disconnect fluid temperature sensor multiplug.
3.Position absorbent cloth under each gearbox
cooler hose connection to collect spillage.
4.Push against coupling release ring and
disconnect both fluid hoses from cooler.
5.Remove screw and release cooler from
radiator.
6.Carefully remove cooler.7.Remove temperature sensor and discard
sealing washer.
Refit
1.Use new sealing washer and tighten
temperature sensor to 14 Nm (10 lbf.ft).
2.Fit cooler, engage with radiator and secure with
screw.
3.Connect temperature sensor multiplug.
4.Ensure connections are clean and fit hoses to
cooler.
5.Fit intercooler.

+ ENGINE MANAGEMENT SYSTEM -
Td5, REPAIRS, Intercooler.
6.Check and if necessary top up gearbox fluid.

AUTOMATIC GEARBOX - ZF4HP22 - 24
44-50 REPAIRS
Cooler - fluid - V8
$% 44.24.10
Remove
1. If fitted: Remove engine oil cooler.

+ ENGINE - V8, REPAIRS, Cooler -
engine oil.
2.Disconnect fluid temperature sensor multiplug.
3.Position absorbent cloth under each gearbox
cooler hose connection to collect spillage.
4.Push against coupling release ring and
disconnect both fluid hoses from cooler.
CAUTION: Always fit plugs to open
connections to prevent contamination.
5.Remove screw and release cooler from
radiator.
6.Carefully move radiator towards engine and
remove cooler.7.Remove temperature sensor and discard
sealing washer.
Refit
1.Use new sealing washer and tighten
temperature sensor to 14 Nm (10 lbf.ft).
2.Fit cooler, engage with radiator and secure with
screw.
3.Connect temperature sensor multiplug.
4.Ensure connections are clean and fit hoses to
cooler.
5. If fitted:Fit engine oil cooler.

+ ENGINE - V8, REPAIRS, Cooler -
engine oil.
6.Check and if necessary top up gearbox fluid.

FRONT AXLE
54-2 DESCRIPTION AND OPERATION
Description
General
The front axle consists of an axle casing with a differential unit attached to the right of the vehicle centre line. A wheel
hub is installed in a steering knuckle at each end of the axle casing and connected to the differential unit by a drive
shaft.
Axle casing
The axle casing is of welded construction, with brackets on the casing exterior for attachment to the front suspension.
Yokes at each end of the casing incorporate upper and lower ball joints for attachment of the steering knuckles.
A differential cover on the front of the axle casing contains an oil level plug for checking and replenishment of the
differential lubricating oil. A magnetic drain plug is installed on the underside of the casing. An oil seal is installed in
each end of the axle casing to prevent leakage past the drive shafts.
The interior of the axle casing is ventilated through a breather tube inserted in a red plastic sleeve in the top of the
casing. The open end of the breather tube is located in the left rear corner of the engine compartment.
Differential unit
The differential unit is of the spiral bevel type, lubricated by splash oil. The unit consists of a differential carrier
attached to a pinion housing. In the pinion housing, the pinion is splined to a drive flange which is secured with a bolt
and washer. An oil seal prevents leakage past the drive flange.
Steering knuckle
The steering knuckles are mounted on upper and lower ball joints in the yokes at the end of the axle casing. A tension
collet, in the lower mounting point of each steering knuckle, accommodates manufacturing tolerances to enable the
correct tightening of both ball joints. Lugs are incorporated on the steering knuckles for attachment of the steering
system drag link and track rod.