Engine Controls - System/component Tests BMW Z3 E36

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 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. Diagnostic Trouble Codes (DTCs) can also be assessed using generic scan tool connected to Data Link Connector. See TESTS W/CODES article. Resistance values can be measured directly on component. See WIRING DIAGRAMS article for additional information.

Ground, Power & Input/Output Circuits

Testing information is not available from manufacturer. See WIRING DIAGRAMS article to identify DME/Motronic control unit ground circuits, power circuits and input/output circuits. (Scheme 77) See DME ECU CONTROL UNIT LOCATION table.

Scheme 77

DME ECU 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.

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.

CAMSHAFT POSITION (CYLINDER IDENTIFICATION) SENSOR LOCATION

RELAYS

For fuel pump relay, see FUEL DELIVERY under FUEL SYSTEM. For relay locations, see DME & FUEL PUMP RELAY LOCATION table.

DME & FUEL PUMP RELAY LOCATION

Scheme 78

Scheme 79

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 80) 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 article in ENGINE PERFORMANCE. Only sockets No. 2, 4, 6 and 8 are used by relay.

Fuel Pressure Regulator

1. Remove fuel pressure regulator. See «REMOVE/INSTALL & OVERHAUL»(/bmw/z3/e36-1995-2000/remont/removal-installation/#engine-controls-removeinstalloverhaul) article ENGINE PERFORMANCE section. Note code number and nominal pressure on fuel pressure regulator body. Install BMW Service Tester (133060) with connecting hose (133064) in fuel feed left line.
2. Remove fuel pump relay. See «DME & FUEL PUMP RELAY LOCATION»(/bmw/z3/e36-1995-2000/remont/testing-diagnostics/#engine-controls-systemcomponent-tests) table. Connect jumper wire between relay base terminals No. 30 and 87. Read off fuel injection pressure on pressure gauge.
3. If fuel pressure drops rapidly, seal return line (upper line) with Clamp (133010) and briefly operate fuel pump. If injection pressure in now stable, pressure regulator is defective. If injection pressure drops, check for leak in front of pressure regulator.

Fuel Pressure Check (Lack Of Power)

Run engine at idle and check fuel pressure. See FUEL PRESSURE REGULATOR. Disconnect vacuum hose from fuel pressure regulator, simulating wide open throttle. If fuel pressure does not increase 5.8-10.1 psi (.40-.71 kg/cm 2 ), replace vacuum hose and repeat test. If fuel pressure still does not increase, replace fuel pressure regulator.

Fuel Pressure Check (Hard Start)

1. Run engine at idle then turn off. Note fuel pressure. Note fuel pressure again after 20-30 minutes. If fuel pressure decreases by greater than 7.2 psi (.5 kg/cm 2 ), turn engine on, wait for pressure to stabilize, then turn engine off and immediately clamp off intake line near pressure gauge with Clamp (133010). Note fuel pressure. Read fuel pressure again after 20-30 minutes.
2. If fuel pressure drops by less than 7.2 psi (.5 kg/cm 2 ), check for fault in fuel supply lines, in-tank supply hose, or defective non-return valve in fuel pump. If fuel pressure again drops by more than 7.2 psi (.5 kg/cm 2 ), replace pressure regulator.

Fuel Volume

Disconnect fuel return line. Attach an extension hose. Place hose in Measuring Glass (133020). Remove fuel pump relay. Apply battery voltage to relay base terminals No. 30 and 87. (Scheme 80) Fuel volume should be about 2 qts. (2.0L) per minute.

Scheme 80

Fuel Injector

Individual fuel injector resistance should be 15-17 ohms. Injector group resistance should be 7.5-8.5 ohms for 4-cylinder engine and V8 (each bank) and 5-6 ohms for 6-cylinder engine.

IDLE SPEED CONTROL VALVE

See IDLE SPEED CONTROL VALVE LOCATION table. Idle speed control valve is either a 2-pin or 3-pin type. (Scheme 81)and (Scheme 82). See appropriate RESISTANCE SPECIFICATIONS table under SPECIFICATIONS.

Scheme 81

Scheme 82

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 .

FUEL EVAPORATION CONTROL SOLENOID LOCATION

SPECIFICATIONS

RESISTANCE SPECIFICATIONS (4-CYLINDER)

RESISTANCE SPECIFICATIONS (6-CYLINDER)

RESISTANCE SPECIFICATIONS (V8)

See also:
• BASIC TESTING
• TESTS W/CODES
• REMOVE/INSTALL & OVERHAUL
• DME ECU CONTROL UNIT LOCATION
• SPECIFICATIONS