INTRODUCTION
Before testing separate components or systems, perform procedures in BASIC TESTING article. Since many computer-controlled and monitored components set a trouble code if they malfunction, also perform procedures in TESTS W/CODES article.
Note. System and component testing of BMW DME/Motronic engine management system is best accomplished using the BMW MoDIC (hand-held scan tester), BMW Service Tester (Sun 2013 Engine Analyzer) and applicable BMW diagnostic software. Tester permits technician to activate components and monitor "status" inquiries. System and component testing information is not available from manufacturer; only resistance values of individual components are included in this article. Resistance values can be measured directly on component. See PIN VOLTAGE CHARTS article and WIRING DIAGRAMS section for additional information.
Ground, Power & Input/Output Circuits
Testing information is not available from manufacturer. See PIN VOLTAGE CHARTS and WIRING DIAGRAMS sections to identify DME/Motronic control unit ground circuits, power circuits and input/output circuits. See DME/MOTRONIC CONTROL UNIT LOCATION table.
| Application | Location |
|---|---|
| All Models | Inside Box On Right Rear Corner Of Engine Compartment, Behind Strut Tower |
DME/MOTRONIC CONTROL UNIT LOCATION
CRANKSHAFT (SPEED/POSITION PULSE) SENSOR
Crankshaft (speed/position pulse) sensor is located on front right side of engine, next to crankshaft pulley. See appropriate RESISTANCE SPECIFICATIONS table under SPECIFICATIONS.
ENGINE (COOLANT) TEMPERATURE SENSOR
See ENGINE (COOLANT) TEMPERATURE SENSOR LOCATION table. See appropriate RESISTANCE SPECIFICATIONS table under SPECIFICATIONS.
| Application | Location |
|---|---|
| All Models | On Front Left Side Of Engine, Below Intake Manifold |
ENGINE (COOLANT) TEMPERATURE SENSOR LOCATION
INTAKE AIR TEMPERATURE SENSOR
Intake air temperature sensor is mounted in intake manifold near mass airflow meter assembly. See appropriate RESISTANCE SPECIFICATIONS table under SPECIFICATIONS .
CAMSHAFT POSITION (CYLINDER IDENTIFICATION) SENSOR
See CAMSHAFT POSITION (CYLINDER IDENTIFICATION) SENSOR LOCATION table. See appropriate RESISTANCE SPECIFICATIONS table under SPECIFICATIONS .
| Application | Location |
|---|---|
| All Models | On Front Left Side Of Engine, Just Behind Coolant Hose Outlet |
CAMSHAFT POSITION (CYLINDER IDENTIFICATION) SENSOR LOCATION
RELAYS
For fuel pump relay, see FUEL DELIVERY under FUEL SYSTEM. Additional information is not available from manufacturer. For relay locations, see DME/MOTRONIC SYSTEM RELAYS LOCATION table.
| Application | (1) Location |
|---|---|
| 325i, 325iC, 325is | (2) Behind Cover, Along Engine Compartment Firewall |
| 525i & 525iT | (2) Right Inner Fender Panel Of Engine Compartment |
| (1) (Scheme 10) (2) First relay (viewed from left to right) after ground wire is fuel pump relay followed by Digital Motor Electronics (DME) master relay. | |
| (1) | (Scheme 10) |
| (2) | First relay (viewed from left to right) after ground wire is fuel pump relay followed by Digital Motor Electronics (DME) master relay. |
DME/MOTRONIC SYSTEM RELAYS LOCATION
Scheme 10
Scheme 11
FUEL DELIVERY
Note. For fuel system pressure testing, see BASIC TESTING article.
Fuel Pump Relay
Remove fuel pump relay. Apply battery voltage to relay terminals No. 30 and 86. (Scheme 12) Ground relay terminal No. 85. Voltage should now exist at relay terminal No. 87. Replace relay if it does not work as indicated.
Note. If relay does not work on vehicle, check battery feed, DME master (main) relay, DME/Motronic control unit and ground circuits going to fuel pump relay. See WIRING DIAGRAMS section. Only sockets No. 2, 4, 6 and 8 are used by relay.
Scheme 12
Fuel Injector
Individual fuel injector resistance should be 15-17 ohms. See appropriate RESISTANCE SPECIFICATIONS table under SPECIFICATIONS.
IDLE SPEED CONTROL VALVE
See IDLE SPEED CONTROL VALVE LOCATION table. See appropriate RESISTANCE SPECIFICATIONS table under SPECIFICATIONS .
| Application | Location |
|---|---|
| All Models | At Left Front Of Engine, Near Dipstick |
IDLE SPEED CONTROL VALVE LOCATION
IGNITION SYSTEM
Note. For basic ignition checks, see BASIC TESTING article.
Fuel Tank Vent (Evaporation) Control Solenoid
See FUEL EVAPORATION CONTROL SOLENOID LOCATION table. See appropriate RESISTANCE SPECIFICATIONS table under SPECIFICATIONS .
| Application | Location |
|---|---|
| 325i, 325iC & 325is | On Left Shock Tower |
| 525i & 525iT | Next To Dipstick |
FUEL EVAPORATION CONTROL SOLENOID LOCATION
SPECIFICATIONS
| Component | (1) Ohms | |
|---|---|---|
| Mass Air Sensor | ||
| Between Terminals No. 5 & 6 | 3-4 | |
| Between Terminals No. 1 & 5 | 16,300 | |
| Camshaft Sensor | 1.3-1.5 | |
| Crankshaft (Speed/Position Pulse) Sensor | 490-590 | |
| Engine (Coolant) Temperature Sensor | ||
| 9-19°F (-13 To -7°C) | 8260-10,560 | |
| 63-73°F (17-23°C) | 2200-2700 | |
| 171-181°F (77-83°C) | 290-364 | |
| Fuel Evaporation Control Solenoid | 40-50 | |
| Fuel Injector | 15-17 | |
| Idle Speed Control Valve (Per Winding) | 20-25 | |
| Ignition Coil (Primary) | 0.8 | |
| Intake Air Temperature Sensor | ||
| 63-73°F (17-23°C) | 2200-2700 | |
| 117-127°F (47-53°C) | 760-910 | |
| Throttle Position (TP) Sensor | 4600 | |
| (1) Measured at an ambient air temperature of 64-82°F (18-28°C). | ||
| (1) | Measured at an ambient air temperature of 64-82°F (18-28°C). |
RESISTANCE SPECIFICATIONS
Wiring Diagram (325i, 325iC & 325is 2.5L - 1 Of 2). Scheme 13
Wiring Diagram (325i, 325iC & 325is 2.5L - 2 Of 2). Scheme 14
Wiring Diagram (525i & 525iT 2.5L - 1 Of 2). Scheme 15
Wiring Diagram (525i & 525iT 2.5L - 2 Of 2). Scheme 16
See also:
• BASIC TESTING
• WIRING DIAGRAMS
• SPECIFICATIONS
• FUEL DELIVERY