1985 BMW 3 SERIES section 17

Caution: If the radio in your
vehicle is equipped with an anti-
theft system, make sure you
have the correct activation code before
disconnecting the battery. Refer to the
information on page 0-7 at the front of this
manual before detaching the cable.
Note: If, after connecting the battery, the
wrong language appears on the instrument
panel display, refer to page 0-7 for the
language resetting procedure.
8Loosen the cable adjuster locknuts, and
detach the cable from its support bracket
located on the intake manifold (see
illustration).
9Pinch the plastic retainer with a pair of
needle-nose pliers, and push it out of the
bracket (see illustration).10Pull the cable down through the slot and
away from the bracket (see illustrations).
11Working from underneath the driver’s side
of the facia, reach up and detach the
accelerator cable from the top of the pedal.
12Pull the cable through the bulkhead, from
the engine compartment side.
13Refitting is the reverse of removal. Adjust
the cable as described earlier.
10 Carburettor-
general information
1Early models are fitted with a Solex 2B4
carburettor, and later models are fitted with a
Solex 2BE carburettor. Both carburettors are
of downdraught, two-stage type. The first
stage is operated mechanically by the
accelerator pedal, and the second stage by
vacuum control.
2Each stage has its own float chamber, float
assembly and needle valve, designed to
reduce the effects of braking and centrifugal
forces.
3On the 2B4 version, the primary stage
choke valve is operated by an automatic
choke (a bi-metal spring which is electrically
heated) during the warm-up period. Warm-up
enrichment is also provided by a coolant-
operated thermal valve and air temperature-
controlled flow valve.
4On the 2BE version, an electronic controlunit is used to automatically adjust the
carburettor settings during warm-up and
normal temperature operation. The control
unit is located beneath the right-hand side of
the facia.
11 Carburettor-
removal and refitting
2
Removal
1Remove the air cleaner as described in
Section 8.
2Disconnect the accelerator cable from the
carburettor with reference to Section 9.
3On automatic transmission models,
disconnect the kickdown cable.
4Disconnect the wiring from the carburettor,
noting the location of each wire.
5Remove the screw, and disconnect the
earth cable from the throttle positioner
bracket (see illustration).
6Disconnect the vacuum hoses, noting that
the hose with the white tracer is located on
the white plastic ‘T’ piece, and the distributor
vacuum hoses are located on the side of the
carburettor (see illustration).
7On the 2B4 carburettor, disconnect and
plug the coolant hoses from the TM (thermal
starter) valve.
8Disconnect the fuel supply hose (see
illustration).
4•10 Fuel and exhaust systems
11.8 Disconnect the fuel supply hose
(arrowed)11.6 Note the locations of the carburettor
vacuum hoses (arrowed) before
disconnecting them11.5 Remove the screw, and disconnect
the carburettor earth cable (arrowed)
9.10b After the cable is off the throttle
valve assembly, remove the plastic
retainer from the cable
9.10a Rotate the throttle valve and remove
the cable end from the slotted portion of
the valve9.9 Pinch the plastic retainer, and push it
through the bracket recess on the throttle
valve9.8 Push the rubber grommet from the
rear, and separate the cable from the
bracket

9Unscrew the four bolts, and lift the
carburettor from the insulating flange on the
intake manifold (see illustration).
10If necessary, unscrew the nuts and
remove the insulating flange from the intake
manifold (see illustration).
Refitting
11Refitting is a reversal of removal, but
clean the mating faces thoroughly. The
insulating flange may be re-used, if it’s in
good condition. Adjust the accelerator cable
with reference to Section 9, and the kickdown
cable (where applicable) with reference to
Chapter 7B.
12 Carburettor-
cleaning and adjustment
4
Note:This Section describes the procedure
for the 2B4 carburettor. The procedure for the
2BE carburettor is similar.
Cleaning
1Obtain a complete set of gaskets and seals
for the carburettor.
2Wash clean the exterior surfaces of the
carburettor.3Using a screwdriver, prise the accelerator
pump linkage from the primary throttle arm
(see illustration).
4Unscrew the bolts securing the cover to the
main body. An Allen key is necessary to
remove the centre bolt (see illustration).
5Prise the link from the choke valve plastic
lever (see illustration).
6Lift the cover from the main body, and
remove the gasket (see illustrations).
7Remove the screw securing the throttle
positioner bracket to the throttle housing (see
illustration).
8Disconnect the vacuum unit pullrod from
the secondary throttle lever (see illustration).
Fuel and exhaust systems 4•11
12.3 Using a screwdriver to disconnect
the accelerator pump linkage (arrowed)11.10 Carburettor insulating flange on the
intake manifold can be removed if
necessary11.9 Unscrew the four bolts (arrowed) and
lift the carburettor from the intake
manifold
12.7 Throttle positioner bracket-to-throttle
housing screw (arrowed)12.6c View of the carburettor main body
with the cover removed12.6b View of the underside of the cover
12.6a Lifting the cover from the
carburettor main body12.5 Prise the link (arrowed) from the
choke valve plastic lever12.4 Using an Allen key to remove the
carburettor cover centre bolt
4

8Check the fuel system pressure (see
Section 3).
9If these checks do not locate the problem,
take the vehicle to a BMW dealer, who will be
able to read the fault codes stored in the ECU,
using special equipment.
16 Airflow meter- check,
removal and refitting
2
Check (L-Jetronic systems)
1Remove the duct from the intake end of the
airflow meter. Carefully open and close the
sensor flap (see illustration), and check for
binding. The flap can bend during a backfire,
and cause incorrect resistance readings. The
flap will bind and stick in a partially-open
position, causing the engine to run rich, and
stall when it returns to idle.
2Disconnect the electrical connector from
the airflow meter.
3Using an ohmmeter, check the resistancebetween terminals 7 and 8 (see illustration).
The resistance should increase steadily
(without any “flat spots”) as the sensor flap is
slowly moved from the fully-closed position to
the fully-open position.
4Also, check the intake air temperature
sensor (inside the airflow meter). Using an
ohmmeter, probe terminals 8 and 9 (see
illustration 16.3)and check for the proper
resistance. The resistance should be 2200 to
2700 ohms at 20º C.
5If the resistance readings are correct, check
the wiring harness (see Chapter 12). Plug in
the connector to the airflow meter. Ensure
that the ignition is switched off. Disconnect
the electrical connector from the ECU (located
under the right-hand side of the facia) and
probe terminals 7 and 8 (see illustration)with
an ohmmeter. Carefully move the door of the
airflow meter, and observe the change in
resistance as it moves from closed to fully-
open. The test results should be the same as
paragraph 3. If there are any differences in the
test results, there may be a shorted-out or
broken wire in the harness.
Check (Motronic systems)
6Ensure that the ignition is switched off.Remove the ECU access cover (see Chap-
ter 6) and disconnect the harness connector
(see illustration).
7Using an ohmmeter, probe the designated
terminals of the ECU electrical connector (see
illustrations)and check for the proper
change in resistance while moving the sensor
flap. On early Motronic systems, probe
terminals 7 and 9. On later Motronic systems,
probe terminals 7 and 12. The resistance
should increase steadily (without any “flat
spots”) as the sensor flap is slowly moved
from the fully-closed position to the fully-open
position. Note: Early Motronic systems are
distinguishable by the 35-pin ECU electrical
connector; later Motronic systems use a 55-
pin connector.
8If the resistance readings are incorrect,
check the wiring harness.
Removal and refitting (all
systems)
9Disconnect the electrical connector from
the airflow meter.
10Remove the air cleaner assembly (see
Section 8).
11Remove the nuts (see illustrations), and
lift the airflow meter from the engine
compartment or from the air cleaner
assembly.
12Refitting is the reverse of removal.
Fuel and exhaust systems 4•15
16.5 The ECU is located under the right-
hand side of the facia. Unplug the
electrical connector, and check the
resistance between terminals 7 and 8 as in
paragraph 3. The test results should be the
same.
16.3 Connect an ohmmeter to terminals 7
and 8 of the airflow meter, and check for a
smooth change in resistance as the vane
door of the airflow meter is slowly opened
and closed16.1 Check for binding of the flap in the
airflow meter as it nears closing position
or wide-open position. Any hesitation or
binding will cause erratic idle conditions,
rich fuel mixture or poor acceleration and
throttle response (airflow meter removed
for clarity)
16.7b Unplug the connector, connect the
ohmmeter probes to terminals 7 and 9
(early Motronic systems) and check for a
smooth change in resistance as the door
on the airflow meter is slowly opened and
closed16.7a Connect the ohmmeter probes to
terminals 7 and 12 (later Motronic systems)
of the ECU connector and check for a
smooth change in resistance as the door
on the airflow meter is slowly opened and
closed16.6 Remove the under-facia panel to gain
access to the ECU on Motronic systems
(left-hand-drive model shown)
4

17 Throttle body- check,
removal and refitting
2
Check
1Detach the air intake duct from the throttle
body (see Section 8) and move the duct out of
the way.
2Have an assistant depress the throttle
pedal while you watch the throttle valve.
Check that the throttle valve moves smoothly
when the throttle is moved from closed (idle
position) to fully-open (wide-open throttle).
3If the throttle valve is not working properly,
renew the throttle body unit.
Warning: Wait until the engine is
completely cool before beginning
this procedure.
Caution: If the radio in your
vehicle is equipped with an anti-
theft system, make sure you
have the correct activation code
before disconnecting the battery. Refer to
the information on page 0-7 at the front of
this manual before detaching the cable.
Note: If, after connecting the battery, the
wrong language appears on the instrument
panel display, refer to page 0-7 for the
language resetting procedure.
Removal and refitting
4Detach the battery negative cable.
5Detach the air intake duct from the throttle
body, and place to one side.
6Detach the accelerator cable from the
throttle body (see Section 9).
7Detach the cruise control cable, if applicable.
8Clearly label all electrical connectors
(throttle position sensor, cold start injector,
idle air stabiliser, etc), then unplug them.
9Clearly label all vacuum hoses, then detach
them.
10Unscrew the radiator or expansion tank
cap to relieve any residual pressure in the
cooling system, then refit it. Clamp shut the
coolant hoses, then loosen the hose clamps
and detach the hoses. Be prepared for some
coolant leakage.11Remove the throttle body mounting nuts
(upper) and bolts (lower), and detach the
throttle body from the air intake plenum (see
illustration).
12Cover the air intake plenum opening with
a clean cloth, to prevent dust or dirt from
entering while the throttle body is removed.
13Refitting is the reverse of removal. Be sure
to tighten the throttle body mounting nuts to
the torque listed in this Chapter’s Specifica-
tions, and adjust the throttle cable (see
Section 9) on completion.
18 Fuel pressure regulator-
check and renewal
3
Warning: Fuel is extremely
flammable, so take extra
precautions when you work on
any part of the fuel system. Don’t
smoke, or allow open flames or bare light
bulbs, near the work area. Don’t work in a
garage where a natural gas-type appliance
(such as a water heater or clothes dryer)
with a pilot light is present. If you spill any
fuel on your skin, rinse it off immediately
with soap and water. When you perform
any kind of work on the fuel system, wear
safety glasses, and have a fire
extinguisher on hand.
Caution: If the radio in your
vehicle is equipped with an anti-
theft system, make sure you
have the correct activation code
before disconnecting the battery. Refer to
the information on page 0-7 at the front of
this manual before detaching the cable.
Note: If, after connecting the battery, the
wrong language appears on the instrument
panel display, refer to page 0-7 for the
language resetting procedure.
Check
1Depressurise the fuel system (see Sec-
tion 2).
2Detach the battery negative cable.
3Disconnect the fuel line and connect a fuel
pressure gauge (see Section 3). Reconnect
the battery.4Pressurise the fuel system (refit the fuel
pump fuse and switch on the ignition), and
check for leakage around the gauge
connections.
5Connect a vacuum pump to the fuel
pressure regulator (see illustration).
6Run the fuel pump (see Section 3). Read the
fuel pressure gauge with vacuum applied to
the pressure regulator, and also with no
vacuum applied. The fuel pressure should
decrease as vacuum increases.
7Stop the fuel pump and reconnect the
vacuum hose to the regulator. Start the engine
and check the fuel system pressure at idle,
comparing your reading with the value listed
in this Chapter’s Specifications. Disconnect
the vacuum hose and watch the gauge - the
pressure should jump up to maximum as soon
as the hose is disconnected.
8If the fuel pressure is low, pinch the fuel
return line shut and watch the gauge. If the
pressure doesn’t rise, the fuel pump is
defective, or there is a restriction in the fuel
feed line. If the pressure now rises sharply,
renew the pressure regulator.
9If the indicated fuel pressure is too high,
stop the engine, disconnect the fuel return line
and blow through it to check for a blockage. If
there is no blockage, renew the fuel pressure
regulator.
10If the pressure doesn’t fluctuate as
described in paragraph 7, connect a vacuum
4•16 Fuel and exhaust systems
18.5 Carefully watch the fuel pressure
gauge as vacuum is applied (fuel pressure
should decrease as vacuum increases)
17.11 Remove the nuts (arrowed) and lift
the throttle body from the intake manifold
(the two lower bolts are hidden from view)16.11b Remove the nuts (arrowed) from
the air cleaner housing, and detach the
airflow meter16.11a Push the tab and remove the air
duct from inside the air cleaner assembly

gauge to the pressure regulator vacuum hose,
and check for vacuum (engine idling).
11If there is vacuum present, renew the fuel
pressure regulator.
12If there isn’t any reading on the gauge,
check the hose and its port for a leak or a
restriction.
Renewal
13Depressurise the fuel system (see Sec-
tion 2).
14Detach the battery negative cable.
Caution: If the radio in your
vehicle is equipped with an anti-
theft system, make sure you
have the correct activation code
before disconnecting the battery. Refer to
the information on page 0-7 at the front of
this manual before detaching the cable.
Note: If, after connecting the battery, the
wrong language appears on the instrument
panel display, refer to page 0-7 for the
language resetting procedure.
15Detach the vacuum hose and fuel return
hose from the pressure regulator, then
unscrew the mounting bolts (see illustration).
16Remove the pressure regulator.
17Refitting is the reverse of removal. Be sure
to use a new O-ring. Coat the O-ring with a
light film of engine oil prior to refitting.
18Check for fuel leaks after refitting the
pressure regulator.
19 Cold start injector and
thermotime switch- check
and renewal
2
Warning: Fuel is extremely
flammable, so take extra
precautions when you work on
any part of the fuel system. Don’t
smoke, or allow open flames or bare light
bulbs, near the work area. Don’t work in a
garage where a natural gas-type appliance
(such as a water heater or clothes dryer)
with a pilot light is present. If you spill any
fuel on your skin, rinse it off immediately
with soap and water. When you performany kind of work on the fuel system, wear
safety glasses, and have a fire
extinguisher on hand.
Check
Cold start injector
1The engine coolant should be below 30ºC
for this check. Preferably, the engine should
have been switched off for several hours.
Disconnect the electrical connector from the
cold start injector (see illustration)and move
it aside, away from the work area - there will
be fuel vapour present. Remove the two
screws holding the injector to the air intake
plenum, and take the injector out. The fuel line
must be left connected. Wipe the injector
nozzle. Disable the ignition system by
detaching the coil wire from the centre
terminal of the distributor cap, and earthing it
on the engine block with a jumper wire. Run
the fuel pump for 1 minute by bridging the
appropriate relay terminals (see Section 3).
There must be no fuel dripping from the
nozzle. If there is, the injector is faulty and
must be renewed. Switch off the ignition and
remake the original fuel pump relay
connections.
2Now direct the nozzle of the injector into a
can or jar. Reconnect the electrical connector
to the injector. Have an assistant switch on
the ignition and operate the starter. The
injector should squirt a conical-shaped sprayinto the jar (see illustration). If the spray
pattern is good, the injector is working
properly. If the spray pattern is irregular, the
injector is fouled or damaged, and should be
cleaned or renewed.
3If the cold start injector does not spray any
fuel, check for a voltage signal at the electrical
connector for the cold start injector when the
starter motor is operated (see illustration). If
there is no voltage, check the thermotime
switch.
Thermotime switch
4The thermotime switch detects the
temperature of the engine, and controls the
action of the cold start injector. It is usually
located up front, near the coolant temperature
sensor. The engine coolant should be below
30ºC for this check. Preferably, the engine
should have been switched off for several
hours. Disable the ignition system by detaching
the coil wire from the centre terminal of the
distributor cap, and earthing it on the engine
block with a jumper wire. Pull back the rubber
boot from the thermotime switch (see
illustration)and probe the black/yellow wire
connector terminal with a voltmeter.
5Have an assistant switch on the ignition and
operate the starter. The voltmeter should
register a voltage signal the moment the
starter engages. This signal should last
approximately 6 to 10 seconds, depending on
the temperature of the engine.
Fuel and exhaust systems 4•17
19.2 Watch for a steady, conical-shaped
spray of fuel when the starter motor is
operated19.1 Cold start injector electrical
connector (arrowed) on the M10 engine.
Most cold start injectors are mounted in
the intake manifold18.15 Remove the two bolts (arrowed) and
remove the fuel pressure regulator from
the fuel rail
19.4 Check for a voltage signal on the
black/yellow wire of the thermotime switch
when the ignition is on19.3 Check for a voltage signal (about
12 volts) at the cold start injector connector
when the starter motor is operated
4

Fuel injection system - fault finding
L-Jetronic fuel injection system
Engine difficult to start, or fails to start (when cold)
Probable cause Corrective action
Cold start injector or thermotime switch faulty Test cold start injector and thermotime switch. Renew faulty components (see Section 19)
Fuel pump inoperative Check fuel pump fuse and fuel pump relay (see Sections 3 and 4)
Airflow meter flap (door) binding or stuck
in open position Inspect the airflow meter for damage (see Section 16)
Fuel pressure incorrect Test system pressure (see Section 3). Test fuel pressure regulator (Section 18)
Intake air leaks Inspect all vacuum lines, air ducts, and oil filler and dipstick seals
Fuel injectors clogged or not operating Check fuel injectors (see Section 20) and wiring harness
Coolant temperature sensor faulty or
wiring problem Test coolant temperature sensor (see Chapter 6, Section 4)
Throttle position sensor (TPS) incorrectly adjusted Check TPS adjustment (see Chapter 6, Section 4)
Incorrect ignition timing Check ignition timing (see Chapter 5). Check vacuum advance system
Dirt or other contaminants in fuel Check the fuel and drain the tank if necessary
Faulty ECU Have the ECU tested at a dealer service department or other specialist
Engine difficult to start, or fails to start (when warm)
Probable cause Corrective action
Cold start injector leaking or operating continuously Test cold start injector and thermotime switch (see Section 19)
Fuel pressure incorrect Test fuel pump(s). Renew if necessary (see Section 3)
Insufficient residual fuel pressure Test residual fuel pressure. Renew fuel pump or fuel accumulator as necessary
(see Section 18)
Fuel leak(s) Inspect fuel lines and fuel injectors for leaks. Correct leaks as required (see Chapter 4)
Coolant temperature sensor faulty or
wiring problem Test coolant temperature sensor (see Chapter 6, Section 4)
Vapour lock (warm weather) Check fuel pressure (see Section 3)
EVAP system faulty (where applicable) Check EVAP system (see Chapter 6, Section 6)
Incorrect ignition timing Check ignition timing (see Chapter 5). Check vacuum advance system
Faulty ECU Have the ECU tested at a dealer service department or other specialist
Idle speed control system faulty Test the idle air stabiliser valve (see Section 21)
Engine misses and hesitates under load
Probable cause Corrective action
Fuel injector clogged or faulty Test fuel injectors. Check for clogged injector lines. Renew faulty injectors (see Section 20)
Fuel pressure incorrect Test fuel system pressure (see Section 3). Test fuel pressure regulator (see Section 18)
Fuel leak(s) Inspect fuel lines and fuel injectors for leaks (see Chapter 4)
Engine maintenance Tune-up engine (see Chapter 1). Check the distributor cap, rotor, HT leads and spark
plugs, and renew any faulty components
Airflow meter flap (door) binding, or
stuck in open position Inspect the airflow meter for damage (see Section 16)
Intake air leaks Inspect all vacuum lines, air ducts and oil filler and dipstick seals
Engine has erratic idle speed
Probable cause Corrective action
Idle air stabiliser valve faulty Check the idle air stabiliser valve (see Section 21)
No power to the idle air stabiliser valve Check the idle air stabiliser relay and wiring circuit (see Chapter 12)
Vacuum advance system faulty Check vacuum advance system and electronic vacuum advance relay
Idle speed control unit faulty Have the idle speed control unit checked by a dealer
Motronic fuel injection system
Note:With this system, when faults occur, the ECU stores a fault code in its memory. These codes can only be read by a BMW dealer, as
specialised equipment is required. It may save time to have at least the initial fault diagnosis carried out by a dealer.
Lack of power
Probable cause Corrective action
Coolant temperature sensor faulty, Test coolant temperature sensor and wiring. Repair wiring or renew sensor if
or wire to sensor broken faulty (see Chapter 6)
Fuel pressure incorrect Check fuel pressure from main pump and transfer pump, as applicable (see Section 3)
Throttle plate not opening fully Check accelerator cable adjustment to make sure throttle is opening fully. Adjust cable if
necessary (see Section 9)
Fuel and exhaust systems 4•21
4

Engine difficult to start, or fails to start (when cold)
Probable cause Corrective action
Cold start injector or thermotime switch
faulty (early Motronic system only) Test cold start injector and thermotime switch. Renew faulty components (see Section 19)
Fuel pump not running Check fuel pump fuse and fuel pump relay (see Sections 2 and 3)
Airflow meter flap (door) binding, or
stuck in open position Inspect the airflow meter for damage (see Section 16)
Fuel pressure incorrect Test system pressure (see Section 3)
Intake air leaks Inspect all vacuum lines, air ducts and oil filler and dipstick seals
Fuel injectors clogged or not operating Check fuel injectors (see Section 20) and wiring harness
Coolant temperature sensor faulty or Test coolant temperature sensor (see Chapter 6, Section 4)
wiring problem
TPS (throttle position sensor) incorrectly adjusted Check TPS adjustment (see Chapter 6, Section 4)
Dirt or other contaminants in fuel Check the fuel and drain the tank if necessary
Faulty ECU Have the ECU tested at a dealer service department or other specialist
Crankshaft position signal missing Faulty position sensor or flywheel, or reference pin missing (see Chapter 5)
Engine difficult to start, or fails to start (when warm)
Probable cause Corrective action
Cold start injector leaking or operating
continuously (early Motronic system only) Test cold start injector and thermotime switch (see Section 19)
Fuel pressure incorrect Test fuel pressure (see Section 3)
Insufficient residual fuel pressure Test fuel system hold pressure (see Section 3)
Fuel leak(s) Inspect fuel lines and fuel injectors for leaks. Correct leaks as necessary
Coolant temperature sensor faulty
or wiring problem Test coolant temperature sensor (see Chapter 6, Section 4)
Vapour lock (in warm weather) Check fuel pressure (see Section 3)
EVAP system faulty Check EVAP system (see Chapter 6, Section 6)
Faulty ECU Have the ECU tested at a dealer service department or other specialist
Idle speed control system faulty Test the idle air stabiliser valve (see Section 21)
Oxygen sensor faulty (where applicable) Check the oxygen sensor (see Chapter 6, Section 4)
Engine misses and hesitates under load
Probable cause Corrective action
Fuel injector clogged Test fuel injectors. Check for clogged injector lines. Renew faulty injectors (see Section 20)
Fuel pressure incorrect Test fuel system pressure (see Section 3). Test fuel pressure regulator (see Section 18)
Fuel leak(s) Inspect fuel lines and fuel injectors for leaks (see Chapter 4)
Engine maintenance Tune-up engine (see Chapter 1). Check the distributor cap, rotor, HT leads and spark
plugs, and renew any faulty components
Airflow meter flap (door) binding, or Inspect the airflow meter for damage (see Section 16)
stuck in open position
Intake air leaks Inspect all vacuum lines, air ducts, and oil filler and dipstick seals
Throttle position sensor (TPS) incorrectly adjusted Check TPS adjustment (see Chapter 6)
Engine idles too fast
Probable cause Corrective action
Accelerator pedal, cable or throttle valve binding Check for worn or broken components, kinked cable, or other damage. Renew faulty
components
Air leaking past throttle valve Inspect throttle valve, and adjust or renew as required
Engine has erratic idle speed
Probable cause Corrective action
Idle air stabiliser valve faulty Check the idle air stabiliser valve (see Section 21)
No power to the idle air stabiliser valve Check the idle air stabiliser relay and wiring circuit (see Chapter 12)
Idle speed control unit faulty Have the idle speed control unit checked by a dealer
Poor fuel economy
Probable cause Corrective action
Cold start injector leaking
(early Motronic system only) Test and, if necessary, renew cold start injector (see Section 19)
Oxygen sensor faulty (where applicable) Test the oxygen sensor (see Chapter 6, Section 4))
Sticking handbrake/binding brakes Check the handbrake/braking system (see Chapter 9)
Tyre pressures low Check tyre pressures (Chapter 1)
4•22 Fuel and exhaust systems

1 General information
The engine electrical systems include all
ignition, charging and starting components.
Because of their engine-related functions,
these components are discussed separately
from body-related electrical devices such as
the lights, the instruments, etc. (which are
included in Chapter 12).
Always observe the following precautions
when working on the electrical systems:
a) Be extremely careful when servicing
engine electrical components. They are
easily damaged if improperly checked,
connected or handled.
b) Never leave the ignition switched on for
long periods of time with the engine off.
c) Don’t disconnect the battery cables while
the engine is running.
d) Observe the rules when jump-starting
your vehicle. Read the precautions at the
front of this manual.
e) Always disconnect the battery negative
cable first, and connect it last, to reduce
the risk of accidental short-circuits.
f) Don’t charge the battery with the cables
connected to the terminals.
It’s also a good idea to review the safety-
related information regarding the engine
electrical systems in the “Safety first”section
near the front of this manual before beginning
any operation included in this Chapter.
Caution: If the radio in your
vehicle is equipped with an anti-
theft system, make sure you
have the correct activation code
before disconnecting the battery. Refer to
the information on page 0-7 at the front of
this manual before detaching the cable.
Note: If, after connecting the battery, the
wrong language appears on the instrument
panel display, refer to page 0-7 for the
language resetting procedure.
2 Battery-
emergency jump starting
1
Refer to the “Jump starting”procedure at
the front of this manual.
3 Battery- removal and refitting
1
Note:Depending on the model, the battery
may be located in the engine compartment, in
the rear luggage compartment, or under the
rear seat. Consult your owners handbook for
the location of the battery, if not already
known to you.Caution: If the radio in your
vehicle is equipped with an anti-
theft system, make sure you
have the correct activation code
before disconnecting the battery. Refer to
the information on page 0-7 at the front of
this manual before detaching the cable.
Note: If, after connecting the battery, the
wrong language appears on the instrument
panel display, refer to page 0-7 for the
language resetting procedure.
1Disconnect the battery negative cable.
2Detach the cable from the positive terminal.
3Remove the battery hold-down bracket
(see illustrations)and lift out the battery. Be
careful - it’s heavy. Do not tilt the battery to
any extent while it is being removed, and
store it upright.
4While the battery is out, inspect the carrier
(tray) for corrosion (see Chapter 1).
5If you are renewing the battery, make sure
that you get one that’s identical, with the
same dimensions, amperage rating, cold
cranking rating, etc.
6Refitting is the reverse of removal.
4 Battery cables-
check and renewal
1
Check
1Periodically inspect the entire length of
each battery cable for damage, cracked or
burned insulation, and corrosion.
Poor battery cable connections can cause
starting problems and decreased engine
performance.
Caution: If the radio in your
vehicle is equipped with an anti-
theft system, make sure you
have the correct activation code
before disconnecting the battery. Refer to
the information on page 0-7 at the front of
this manual before detaching the cable.
Note: If, after connecting the battery, the
wrong language appears on the instrument
panel display, refer to page 0-7 for the
language resetting procedure.2Check the cable-to-terminal connections at
the ends of the cables for cracks, loose wire
strands, and corrosion. The presence of
white, fluffy deposits under the insulation at
the cable terminal connection is a sign that
the cable is corroded, and should be cleaned
or renewed. Check the terminals for
distortion, missing mounting bolts, and
corrosion.
Renewal
3When removing the cables, always
disconnect the negative cable first and
connect it up last. This reduces the risk of
accidental short-circuits. Even if only a new
positive cable is being fitted, be sure to
disconnect the negative cable from the
battery first (see Chapter 1 for further
information regarding battery cable removal).
4Disconnect the old cables from the battery,
then trace each of them to their opposite ends
and detach them from the starter solenoid
and earth terminals. Note the routing of each
cable to ensure correct refitting.
5If the old cables are to be renewed, take
them with you when buying new cables. It is
vitally important that you renew the cables
with identical parts. Cables have character-
istics that make them easy to identify: positive
cables are usually red, larger in cross-section,
and have a larger-diameter battery post
clamp; earth cables are usually black, smaller
in cross-section, and have a slightly smaller
diameter clamp for the negative post.
6Clean the threads of the solenoid or earth
connection with a wire brush to remove rust
and corrosion.
7Attach the cable to the solenoid or earth
connection, and tighten the mounting nut/bolt
securely.
8Before connecting a new cable to the
battery, make sure that it reaches the battery
post without having to be stretched.
9Connect the positive cable first, followed by
the negative cable.
5•2 Engine electrical systems
3.3b The battery is mounted under the
rear seat on some models
3.3a Always detach the cable from the
battery negative terminal first, then detach
the positive cable – to remove the hold-
down assembly, remove the nuts (arrowed)
or single bolt
Apply a light coat of battery
terminal corrosion inhibitor,
or petroleum jelly, to the
terminal threads, to prevent
future corrosion.