
Downloaded from www.Manualslib.com manuals search engine 
Ignition System 
- Turn ignition on and  check for battery voltage, 
If  battery voltage is not present, 
checlt wire between  termi- 
nal 
15 and the unloader  relay. See ELE Electrical Wiring 
Diagrams. 
- Turn  ignition  off. 
Remove  coil and inspect coil housing  for hairline 
cracks or 
leaking casting material. Replace  any 
cracked or leaking coil. 
NOTE- 
A leaky coil may  indicate a faulty Engine Control Module 
(ECM).  Check ECM before installing a  new coil. 
CAUTION- 
Note  location  of coilground  straps before coil removal;  rein- 
stall  in the  same  location. 
Use a multimeter  to test: 
Coil primary resistance at coil terminals. 
Sparlt plug connector  resistance. 
* Compare results  to specification in  Table c. lgnition  coil 
resistance. 
Table  c. Ignition  coil resistance 
Coil  secondary 
resistance 
Spark plug  connector: 
Bosch 1 .O I( ohm t 20% 
1.8 ir ohm t 20% 
Component 
Co~l prlmary 
resistance 
- Replace ignition coil or sparlt plug connector  if resistance 
readings do  not meet specifications. 
4 Remove ignition coil to  be tested. 
Install 
BMW special tool 12 7 030 (A) on coil  to be  tested. 
Connect ground jumper between  coil  mounting point 
(B) 
and engine  ground point (C). 
Clip scope high pick-up lead (D) around ignition lead. 
Start  engine. 
Compare scope pattern with diagrams in  Oscilloscope 
di- 
agnostic diagrams. 
NOTE- 
When replacing ignition  coils, ensure  that the  replacements 
Terminal 
1 (-) and 15 (+) 
are 
from the  same manufacturer  with the same partlcode 
numbers. If individual  coils with the  correct specifications  are 
not  available.  all coils  should  be 
re~laced. 
Resistance 
0.8 ohms    

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I Battery, Starter, Alternator 
- Check for battery  voltage  at terminal 50 of starter motor with 
key  in start position.  If voltage is not present,  check wiring be- 
tween ignition switch and starter  terminal.  Check the EWS 
system and other inputs that disrupt terminal 
56 to  the  start- 
er.  See  ELE  Electrical 
Wiring Diagrams.  If voltage is 
present  and no other visible wiring  faults can be found, prob- 
lem  is most likely in starter  motor. 
Starter, removing  and  installing 
(6-cylinder  engine) 
The starter is removed  from below.  Access  to starter bolts is 
difficult. Be sure  to have the proper tools on hand before pro- 
ceeding. 
NOTE- 
Access  to the  starter  wiring is very  limited.  Forbetteraccess, 
it  may  be necessary  to remove  the intake manifold. 
- Disconnect negative (-) battery  cable. 
CAUTIOI\C 
Prior to disconnecting the battern read  the baltery  discon- 
nection  cautions 
in OOlGeneral Cautions and  Warnings. 
Remove complete air filter hous~ng: 
Loosen intake duct hose  clamp (A) at throttle  assembly. 
Loosen clamp and  remove idle control hose from  intake 
duct 
(B) and disconnect idle  speed control  valve electrical 
harness  connector. 
Disconnect electrical harness connector 
(C) from mass air 
flow  sensor. 
Remove  air filter housing mounting  screw (D) 
Disconnect  vent tube 
(E). 
Loosen air intake duct  clamp (F). 
Carefully lift air filter housing  out of engine  bay. 
Disconnect throttle cable. 
Raise vehicle and support  safely. 
WARNING- 
Make sure the car is stable  and well supported  at all times. 
Use  a professional  automotive 
lift orjack stands designed  for 
the purpose.  A 
floorjaclc is not  adequate  support 
- Working underneath  car, remove  engine splash shield 
- Disconnect fuel lines and harness connectors  from retaining 
brackets, as  necessary.    

Downloaded from www.Manualslib.com manuals search engine 
130-1 
130 Fuel injection 
General ........................... .I3 0.2 
Tools and test equipment .............. .I3 0.3 
Warnings and cautions ................ .I3 0.5 
Fuel Supply ....................... .I3 0.6 
Relieving system  fuel pressure .......... .I3 0.6 
Siemens MS  41 . 1. ................... 1 30-7 
ECM relay.  testing .................... .I3 0.7 
Mass air flow (MAF)  sensor. 
checking and replacing 
................ .I3 0.9 
Engine coolant temperature (ECT) sensor. 
testing and replacing 
.................. 130-10 
Intake  air temperature  (IAT) sensor. 
testing and replacing 
................. .I3 0.1  1 
Throttle position  sensor (TPS). 
testing and replacing 
.................. 130-1 2 
ldle speed control  valve. 
checking and replacing 
............... .I3 0.1 3 
Fuel injectors. checking and  replacing .... 130-15 
Evaporative emissions. overview ....... .I3 0.1 6 
Secondary  air  injection. overview ....... .I3 0-17 
Engine control  module (ECM). 
removing and installing 
................ 130-18 
Siemens MS 41.1 ECM  pin assignments . .I3 0.19 
Siemens MS 42.0  and MS 43.0. ..... .I3 0.23 
ECM relay. testing ................... .I3 0.27 
Mass air flow  (MAF)  sensor. 
checking and replacing 
............... .I3 0.28 
Engine coolant  temperature (ECT) sensor. 
testing and replacing 
................. .I3 0.30 
Intake air temperature  (IAT) sensor. 
testing and replacing 
................. .I3 0.31 
MS 42.0 throttle  valve assembly.  replacing . 130-32 
MS 43.0 throttle valve assembly.  replacing . 130-35 
Throttle cable. adjusting (MS 42.0) ...... .I3 0.38 
ldle speed control  valve. checking 
and replacing 
....................... .I3 0.38 
Evaporative  emissions control diagrams . . 130- 39 
Evaporative emissions control. 
(MS 
42.0 and MS 43.0). .............. .I3 0.39 
Engine control  module (ECM). 
removing and installing 
................ 130-40 
Siemens  MS 42.0 and MS 43.0 
ECM pin  assignments ................. 130-41 
Bosch M5.2 (M62  up to 911997) 
BOSC~ M5.2.1  (M62 911997 to 911998) 130-46 
M5.2 system features ................. 130-47 
M5.2.1 system features ............... 130-47 
ECM relay.  testing ................... 130-49 
Oxygen sensors. checking ............. 130-51 
Fuel injectors. checking and  replacing .... 130-52 
Mass air flow (MAF) sensor. replacing .... 130-53 
ldle  speed control valve.  testing 
and replacing 
....................... 130-54 
Throttle position  sensor (TPS). 
testing and replacing 
................. 130-55 
Engine  coolant temperature  (ECT) sensor. 
testing and replacing 
................. 130-55 
Intake  air temperature (IAT) sensor. 
testing and replacing 
................. 130-57 
Auxiliary throttle valve (ADS)  (M62  and 
M62 TU engine).  replacing ..... 130-57 
Evaporative system pressure 
leak diagnosis. overview 
(5.2.1 only) ..... 130-58 
Bosch 5.2 ECM  pin assignments 
(M62 UP to 911 997) ................... 130-59 
~osch 5.2.1 ECM  pin assignments 
(M62 911 997 to 911 998) ............... 130-62 
BOSC~ ME  7.2 ..................... 1 30-66 
ME 7.2 system overview ............... 130-67 
EDK  adaptation ..................... 130-69 
ECM  relay. checking .................. 130-69 
Engine coolant temperature 
(ECT)  sensor.  testing 
................. 130-71 
Engine coolant temperature 
(ECT) sensor.  replacing 
............... 130-71 
Oxygen sensors. replacing ............. 130-72 
Fuel injectors. removing  and installing .... 130-72 
Mass air flow (MAF) sensor. 
removing  and installing 
................ 130-73 
Evaporative system pressure 
leak  diagnosis. overview 
............... 130-74 
Secondary air  injection. overview ........ 130-75 
Bosch ME 7.2 ECM pin assignments .... 130-76    

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130-6 
Fuel Injection 
Fuel supply  to the  injection  system is  provided by a high pres- 
sure  electric  pump mounted inside  the fuel  tank.  The pump  is 
powered via  the fuel pump relay.  If the relay is faulty,  the fuel 
pump will not  run and  the engine will  not start. 
NOTE- 
* Fuel  delivery  volume and fuel pressure  are critical  to prop- 
er  operation.  Fuel pressure direcfly influences fuel deliv- 
ery 
Fuel pump  relay, fuel pressure  and fuel volume  tests are 
given in 160 Fuel Tank  and Fuel Pump. 
Relieving system fuel pressure 
The fuel system retains fuel  pressure in the  system  when the 
engine  is off. To prevent  fuel from spraying on a  hot engine, 
system fuel pressure  should be relieved beforedisconnecting 
fuel  lines.  One method is  to tightly  wrap 
ashop towel around a 
fuel  line fitting  and loosen  or disconnect  the fitting.  Cleanli- 
ness  is essential  when working with  fuel components. Thor- 
oughly clean the  unions before disconnecting  fuel lines. 
When system faults  are detected, a diagnostic trouble code 
(DTC) is stored  in the engine control module (ECM). The  MIL 
also iiluminates if an emissions-related  fault is detected 
When faults arise,  or if the malfunction indicator lamp (MIL)  is 
illuminated, begin  troubleshooting by connecting  BMW ser- 
vice tester 
DISplus. MoDiC, GTI or  equivalent scan tool. The 
capabilities  of OBD 
II software has the  potential to save hours 
of  diagnostic time and to help  avoid incorrect  component  re- 
placement and  possible damage to system  components. 
CAUTION- 
- The tests in this section may  set fault  codes (DTCs) in the 
ECM and  illuminate  the 
MIL. Affer all testing  is completed, 
access  and clear  DJC fault memory  using an 
OED I1 or 
BMW  compatible scan  tool. See OBD  On-Board  Diag- 
nostics. 
0 Only use  a digital multimeter for  electrical  tests. 
. Relay positions can  vary Be sure  to confirm relay posi- 
tion  by identifying  the wiring  in the socket  using the wir- 
ing  diagrams found  in ELE  Electrical  Wiring 
Diagrams.    

Downloaded from www.Manualslib.com manuals search engine 
Fuel Injection 1 
Working in right  rear of engine compartment: 
Release interior  ventilation filter cover  latch 
(A) and re- 
move cover. 
Release plastic  locking  tab 
(6). 
Rotate duct inward (arrow) to unlock  from bulk head  and 
remove  duct. 
Release spring 
lock (C) to  remove  lower iilter housing. 
Slide filter housing  away from inner  fender  to remove. 
- Remove electrical  box (E-box)  cover fasteners  and remove 
cover. 
NOTE- 
OBD I1 fault  memory  (including  an illuminated MIL)  can 
only  be reset  using  an electronic scan  tool. Removing the 
connector from the  ECM or disconnecting  the battery  will 
not erase  the fault 
memory. 
The  BMW-dedicated 20-pin diagnostic linlc connector 
(DLC) is in the right rear  of the engine  compartment. 
The  16-pin  OBD 
I1 diagnostic connector (arrow) is located 
inside the  car on the  lower left  dash panel. 
ECM relay, testing 
Fuses lor ECM In E-bbx 502130488 
4 The engine control  module (ECM) relay  is energized  via the 
ECM  and supplies  battery  positive 
(B+) power to many  of the 
engine  management  components and subsystems. 
If this re- 
lay  is faulty,  the engine  will not start. 
Relay  positions  can vary.  Be sure  to confirm  relay position  by 
identifying the wiring  in the  socket  using the wiring  diagrams 
in 
ELE Electrical  Wiring Diagrams. 
NOTE- 
The ECM  relay is also  referred to  as the  DME main  relay.    

Downloaded from www.Manualslib.com manuals search engine 
130-8 
Fuel Injection 
With ignition  off, remove main  relay (K6300) (arrow) in 
E-box. 
- With ignition on  and relay installed, check for  battery voltage 
on  terminal 
2 (87). 
4 Check for voltage  at terminal  8 (30) on relay socket. 
If  battery  voltage  is present, relay  has energized  and is 
functioning  correctly. 
Gmund from 6L (hot ~4th k~y key in Ern 
2I '1 
on position) 
to 
Fuel pump RdiWt Rd from Battery and other system components SOZI~O~~I~Y 
If  battery  voltage is  not present  and all earlier tests  are OK, 
relay  is faulty  and should  be replaced. 
If 
battery voltage  is present continue testing. 
If  battery  voltage  is not present, check fuse  109 (80-amp 
fusible  link)  under passenger seat carpet.  See ELE  Elec- 
trical Wiring  Diagrams. 
- Reinstall relay  and turn ignition on. Gain access to back  side 
of  relay socket  and check  for ground on terminal 
4 (85). 
If  ground  is present  continue testing. 
If  ground is  not present,  signal from ECM is missing. Check 
NOTE- 
If no  faults  are found  during testing  but power  is not  reaching 
the 
ECM or  other  components, check the fuses in the fuse 
carrier 
X8680 in the  E-box. 
wire 
between  ECM and relay.    

Downloaded from www.Manualslib.com manuals search engine 
- -. 
Fuel Injection 
SIEMENS MIS 42.0 AND 43.0 
When system faults  are detected, a  diagnostic trouble  code 
(DTC)  is stored  in the  engine  control module  (ECM). The MIL 
also illuminates 
if an emissions-related  fault  is detected. 
When  faults arise,  or 
if the malfunction indicator lamp  (MIL) is 
illuminated, begin  troubleshooting by connecting  BMW ser- 
vice  tester 
DISplus, MoDiC, GTI or equivalent scan tool.  The 
capabilities  of OBD 
II software has  the potential  to save hours 
of  diagnostic  time and to help avoid incorrect component re- 
placement  and possible  damage to system  components. 
CAUTION- 
* The tests  in this section  may set fault  codes (DTCs) in tlie 
ECM  and illuminate the  MIL. After all testing is completed, 
access  and clear DTC  fault 
memory using an OBD I/ or 
BMW  compatible scan  tool. See 
OBD On-Board  Diag- 
nostics. 
Only  use a 
dgital multimeter  for  electrical tests. 
Relay  positions  can vary.  Be sure  to confirm 
relayposi- 
tion by  identifying the  wiring in the socket  using the wir- 
ing  diagrams found in 
ELE Electrical  Wiring 
Diagrams. 
NOTE- 
- OBD I1 fault  memory. (including  an illuminated MIL! can 
only  be reset  using  the special scan  tool. Removing  the 
connector from the  ECM or disconnecting  the battery will 
not erase the  fault memory. 
The  BMW-dedicated  20-pin diagnostic 
linlc connector 
(DLC)  is in  the  right  rear of the engine  compartment  The 
20-pin DLC  is discontinued  on models after 
6/2000. 
The 1 &pin OBD I1 diagnostic connector (arrow) is located 
inside the  car on the lower left  dash panel. 
The  MS 
42.0 and MS 43.0 systems manage  the following 
functions. 
- Air: 
Idle speed  valve 
Electronic  throttle 
Hot  film  mass  air flow  (MAF)  sensor 
Resonance-turbulence  intake control 
- Fuel: 
* Fuel  supply 
Running  losseslnon  return 
Fuel  injection    

Downloaded from www.Manualslib.com manuals search engine 
. . 
Fuel Injection 
Check resistance  of valve  across  valve terminals 
Idle speed  control  valve coil resistance 
Terminals 
1 and 2 20 i2.0. 
Terminals 2 and 3 20 i2.0. 
Terminals 1 and 3 40  i4.0. 
CAUTIOIG 
Be  sure ignition  is OFFbefore disconnecting or  reconnecting 
DME system components. 
- To remove valve, remove cable bracket  mounting bolt and 
idle  speed control  valve mounting bracket bolts from front  of 
throttle  housing  and remove idle  speed control  valve with at- 
tached  bracket. 
NOTE- 
When  installing  idle speed  control  valve, remove intake  boot 
sealing  ring from  valve  and install  into intake  air boot. Then 
install  valve info sealing 
ring. 
Evaporative emissions control diagrams 
MS 42.0 (LDP) ,-a"- 
Evaporative emissions control, 
(MS 42.0, MS 43.0) 
E39  models  with MS 42.0 or MS 43.0 engine  are equipped 
with a  fuel system evaporative pressure leak diagnosis  sys- 
tem.  The main  component  of this system is  the leak diagnosis 
pump (LDP or DM-TL).  The function  of either system  is to 
pressurize  the fuel  tank  and the evaporative emission system 
for  the purpose  of detecting leaks.