COMPUTERIZED ENGINE CONTROLS
| CAUTION | When battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery. |
POWERTRAIN CONTROL MODULE (PCM) FOR DIGITAL MOTOR ELECTRONICS (DME) SYSTEM
Note. Disconnect battery before removing Digital Motor Electronics (DME) module (PCM). Disconnecting battery will clear PCM Diagnostic Trouble Codes (DTCs). Retrieve DTCs before disconnecting battery. PCM stores certain basic driveability values. PCM also receives different input values, depending on engine condition, which are compared with stored values. PCM adaptive system compares input values with stored values. PCM replacement could cause poor engine performance before all values are adapted to engine condition. Before exchanging PCM, ensure engine is at normal operating temperature. Remove old PCM, install new PCM and operate vehicle at different RPMs.
DIRECT IGNITION SYSTEM (DIS)
- Ensure ignition is turned off before working on the ignition system. The engine will not start without a connected secondary circuit. When checking compression, remove Digital Motor Electronics (DME) Electronic Control Unit (PCM) relay. See «DME & FUEL PUMP RELAY LOCATION»(ref-11862-S25034933362000120100000) table under FUEL SYSTEM PRESSURE RELEASE under FUEL SYSTEM.
- Shielded capacitors may not be connected to terminal No. 1 of the ignition coil. Terminal No. 1 of the ignition coil may not be connected to ground or battery positive terminal, as this will damage ignition stages in DME control unit.
- DO NOT connect DVOM or test light to terminal No. 1 of ignition coil while engine is running. High tension (350 volts) is present at coil terminal No. 4, secondary ignition leads, spark plugs and ignition coil terminal No. 1 to DME Powertrain Control Module (PCM).
Note. For location of DME master and fuel pump relays, see DME & FUEL PUMP RELAY LOCATION table under FUEL SYSTEM PRESSURE RELEASE under FUEL SYSTEMS .
FUEL SYSTEMS
| WARNING | Always relieve fuel pressure before disconnecting any fuel injection-related component. DO NOT allow fuel to contact engine or electrical components. |
FUEL SYSTEM PRESSURE RELEASE
Fuel system pressure release procedure not available from manufacturer. It may be possible to remove fuel pump relay, start engine, and run engine until fuel pressure drops (engine stalls). See DME & FUEL PUMP RELAY LOCATION table.
| Application | Location | ||
|---|---|---|---|
| 3-Series | |||
| Z3 | |||
| DME Relay | Right Rear Corner Of Engine Compartment, Next To DME PCM | ||
| Fuel Pump Relay | Under Left Side Of Instrument Panel, Next To Kick Panel | ||
| E46 | |||
| DME Relay | Left Rear Corner Of Engine Compartment, In Relay/PCM Box | ||
| Fuel Pump Relay | Behind Glove Box | ||
| 5-Series & 7-Series | |||
| DME Relay | Right Rear Corner Of Engine Compartment, Next To DME PCM | ||
| Fuel Pump Relay | Right Side Of Trunk | ||
| (1) For relay location illustration, see RELAYS under RELAYS & SOLENOIDS in SYSTEM & COMPONENT TESTING article. | |||
| (1) | For relay location illustration, see RELAYS under RELAYS & SOLENOIDS in SYSTEM & COMPONENT TESTING article. |
DME & FUEL PUMP RELAY LOCATION (1)
ACCELERATOR SENSOR (V12)
Note. When accelerator sensor is disconnected, basic adaptation of accelerator sensor is required. Connect DIS and select diagnosis on EPC-III control unit. Follow procedure set out in DIS instructions.
3-Series (Z3)
Filter on firewall of vehicle: Remove cover from fuel filter. Disconnect fuel delivery line with special tool 13 3 010 before and after the fuel filter. Unfasten hose clips and remove fuel line from fuel filter.
Scheme 203
| CAUTION | Catch and dispose off escaping fuel. |
Unfasten screw and remove filter from bracket. Filter on underbody of vehicle: Unfasten screws and remove cover from fuel filter. Disconnect fuel inlet line at points (1) and (2) with special tool 13 3 010.
Scheme 204
| CAUTION | Catch and dispose off escaping fuel. |
Unfasten hose clips and remove fuel line from fuel filter. Fuel filter with quick release coupling. Push lock toward filter while pulling off fuel hose. Unfasten screw and remove filter from bracket.
Scheme 205
Installation: Check direction of flow (arrow). Arrow must point towards the injection valve strip.
Scheme 206
3-Series (E46)
Turn off ignition. If installed: Remove engine underguard (1 and 2). Disconnect fuel feed line at points (1) with special tool 13 3 010.
Scheme 207
| CAUTION | Catch and dispose of escaping fuel. |
Release hose clips and disconnect fuel lines from fuel filter.
During installation, always replace hose clips and fuel hoses. Release screw (2) and remove filter from retainer.
Scheme 208
Observe flow direction (arrow). Arrow must point in direction of fuel injector block.
M52, M60, M62 & M73
Switch off ignition. Unfasten screws on lower trim (1).
Scheme 209
Fold lower trim to one side.
Scheme 210
Disconnect fuel lines with special tool 13 3 010. Catch and dispose of escaping fuel.
Scheme 211
Illustrated here without lower trim: Unfasten hose clips. Replace hose clips.
Scheme 212
Unfasten screws. Remove fuel filter. Replace fuel filter.
Scheme 213
Installation: Note installation direction of fuel filter. Direction of flow is marked with an arrow on the fuel filter. The arrow points towards the injector strip.
Scheme 214
The embossed designation "OUT " on outlet of fuel filter must be mounted facing the injector strip.
Scheme 215
THROTTLE POSITION SENSOR
Note. For throttle position sensor information, go to THROTTLE BODY .