SELF-DIAGNOSTICS FEATURE
DME/Motronic control unit has a self-diagnostic feature with internal memory. Self-diagnostic feature detects malfunctions in control unit or emission-related components and stores fault codes.
DME/Motronic control unit provides a substitute value if a failure occurs in engine (coolant) temperature sensor, intake air temperature sensor, airflow meter or exhaust gas oxygen sensor. These substitute values are canceled when normal engine operation is resumed. To aid in trouble shooting, stored fault codes and sensor values can be monitored via control unit when components are actuated.
In addition to control of relevant systems, DME/Motronic control unit can supply or receive data for diagnostic procedures. Data can be read out or entered with BMW MoDIC (hand-held scan tester) or BMW Service Tester (Sun 2013 Engine Analyzer) and applicable BMW diagnostic software.
Data exchange between control unit and BMW diagnostic software occurs via Diagnostic Initiation Line (RxD) and Diagnostic Data Line (TxD) in engine diagnostic (connector) socket. (Scheme 10)
After installing diagnostic software in BMW Service Tester, general overview of DME/Motronic control unit appears on display screen. Self-diagnostic procedure is initiated by selecting relevant control unit; corresponding diagnostic program functions are automatically assigned from diagnostic software.
Note. To avoid faults during vehicle operation, RxD line is connected to battery voltage and TxD line to ground when diagnostic (connector) socket cover is closed.
Scheme 10
READ STATUS Diagnostic Function
This function permits technician to read status and current input/output values being received/sent out by DME/Motronic control unit. Compare display with actual status of vehicle. If a signal is found to be defective or if status detected by control unit deviates from actual status of vehicle, carry out trouble shooting of associated input or output (voltage, resistance, etc.).
DRIVE COMPONENTS Diagnostic Function
This function allows technician to drive (actuate) component without DME/Motronic control unit switch-on condition being set. Actual statuses of inputs at control unit are ignored. With this function, proper operation of components can be checked with components installed.
READ DEFECT CODE MEMORY Diagnostic Function
Contents of DME/Motronic control unit defect code memory and operating conditions under which defect occurred can be accessed via this function. More extensive trouble shooting is then carried out in accordance with instructions provided in diagnostic program or diagnostic procedure.
Note. Fault codes (except Codes 26 and 200) are stored after engine has started. If several codes have been stored, they appear in chronological order.
QUICK TEST Function
QUICK TEST permits checking of defect codes on all control units with a self-diagnostic feature. Ignition switch must be turned to ON position before QUICK TEST is started. QUICK TEST is started from general overview of DME/Motronic control unit screen and is indicated by "QUICK TEST ACTIVE" in last (screen) line.
Control units are read out in same sequence as control unit overview. Progression of QUICK TEST is indicated to technician by flashing relevant line of control unit overview. Continuation to second page of control unit overview takes place automatically.
When BMW diagnostic software finds a control unit, corresponding line of DME/Motronic control unit overview is marked by an asterisk (*). If a defect code is stored in control unit, line is highlighted. QUICK TEST can be canceled at any time by pressing any key on BMW Service Tester. Completion of QUICK TEST is indicated by "QUICK TEST COMPLETED" in last (screen) line.
Reading Diagnostic (Flash) Codes
- With ignition switch in RUN position and after depressing accelerator pedal 5 times to WOT, CHECK ENGINE light comes on for 5 seconds to indicate self-diagnostic feature is preparing to output diagnostic codes. (Scheme 11)
- CHECK ENGINE light then turns off for 0.5 second (awaiting synchronization signal), comes on for 2.5 seconds (light check) and again turns off for 2.5 seconds (wait for readout). Last 2.5 second pause tells technician to wait for diagnostic code readout.
- Next CHECK ENGINE light on/off periods represent diagnostic codes stored. CHECK ENGINE light will be on or off for 0.5 second with a 2.5 second pause between each code digit and a 2.5 second pause between each code. (Scheme 11) See appropriate FAULT CODE IDENTIFICATION table under «TROUBLE CODE DEFINITION»(ref-9972-S35325990712000110700000).
Scheme 11
| Code | Component Malfunction | Diagnosis |
|---|---|---|
| 1211 | Digital Motor Electronics (DME) Control Unit | Code indicates failure of DME. Erase stored codes. Start and run vehicle for 30 seconds. Turn ignition off for 30 seconds. If code reoccurs, replace DME. |
| 1212 | Oxygen Sensor No. 2 | Code indicates oxygen sensor signal is out of range or not present at an engine temperature of 158°F (70°C) or more. Check wiring and sensor. Sensor voltage should be 0.02-0.85 volt. |
| 1213 | Oxygen Sensor Control No. 2 | Code indicates DME has detected excessive variation in air-fuel (rich/lean) mixture for greater than 10 seconds. Possible causes include no fuel, inadequate fuel pressure, injector defective, temperature sensor defective, secondary air leak, EVAP system defective, airflow meter defective or engine mechanical problem. |
| 1215 | Mass Airflow Sensor | Code indicates an open or short to voltage or ground at mass airflow sensor or wiring. Check airflow sensor wiring and connections. |
| 1216 | Throttle Position Sensor | Code indicates an open or short to voltage or ground at throttle position sensor or wiring. Check throttle position sensor wiring and connections. |
| 1218 | Output Stage (Bank 1) | Code indicates an open or short to voltage at output amplifier stage (bank 1). Code may be caused by idle speed actuator, EVAP, control valve, CHECK ENGINE light, injectors, ignition coil(s), oxygen sensor heater relay, or EKP relay. Delete code after checking for other faults. Erase code. If code reoccurs, erase code again and reset DME by disconnecting its connector for at least 5 minutes. If code reoccurs and no other problems are present, replace DME. |
| 1219 | Output Stage (Bank 2) | Code indicates an open or short to voltage at output amplifier stage (bank 2). Code may be caused by idle speed actuator, EVAP, control valve, CHECK ENGINE light, injectors, ignition coil(s), oxygen sensor heater relay, or EKP relay. Delete code after checking for other faults. Erase code. If code reoccurs, erase code again and reset DME by disconnecting its connector for at least 5 minutes. If code reoccurs and no other problems are present, replace DME. |
| 1221 | Oxygen Sensor 1 | Code indicates oxygen sensor signal is out of range or not present at an engine temperature of 158°F (70°C) or more. Check wiring and sensor. Sensor voltage should be 0.02-0.85 volt. |
| 1222 | Lambda Control 1 | Code indicates DME has detected excessive variation in air-fuel (rich/lean) mixture for greater than 10 seconds. Possible causes include no fuel, inadequate fuel pressure, injector defective, temperature sensor defective, secondary air leak, EVAP system defective, airflow meter defective or engine mechanical problem. |
| 1223 | Coolant Temperature Sensor | Code indicates an open or short to voltage or ground at coolant temperature sensor or wiring. Check sensor wiring and connections. Sensor value should be 8.3-10.6 k/Ohms at 14°F (-10°C), 2.2-2.7 k/Ohms at 68°F (20°C), and 2.9-3.6 k/Ohms at 140°F (60°C). |
| 1224 | Intake Air Temperature Sensor | Code indicates an open or short to voltage or ground at intake air temperature sensor or wiring. Check sensor wiring and connections. Sensor value should be 2.2-2.7 k/Ohms at 68°F (20°C), and 7.6-9.0 k/Ohms at 122°F (50°C). |
| 1225 | Knock Sensor No. 1 | Code indicates an open or short to voltage or ground at knock sensor No. 1 or its wiring. Check sensor, sensor wiring and connections. Check fuel octane and possible carbon in cylinders. |
| 1226 | Knock Sensor No. 2 | Code indicates an open or short to voltage or ground at knock sensor No. 2 or its wiring. Check sensor, sensor wiring and connections. Check fuel octane and possible carbon in cylinders. |
| 1227 | Knock Sensor No. 3 | Code indicates an open or short to voltage or ground at knock sensor No. 3 or its wiring. Check sensor, sensor wiring and connections. Check fuel octane and possible carbon in cylinders. |
| 1228 | Knock Sensor No. 4 | Code indicates an open or short to voltage or ground at knock sensor No. 3 or its wiring. Check sensor, sensor wiring and connections. Check fuel octane and possible carbon in cylinders. |
| 1231 | Battery Voltage Or DME Main Relay | Check charging system and/or battery. |
| 1232 | Idle Throttle Valve Switch | Code indicates an open or short to voltage or ground at idle throttle valve switch or wiring. Check idle throttle valve switch wiring and connections. |
| 1233 | Full Load Throttle Valve Switch | Code indicates an open or short to voltage or ground at full load throttle valve switch or wiring. Check throttle position sensor wiring and connections. |
| 1234 | Vehicle Speed Sensor | Code indicates an open or short to voltage or ground in speed sensor wiring to DME, or speedometer malfunction. |
| 1237 | A/C Compressor Cut-Off | Code indicates an open or short to voltage or ground in A/C cut-out relay wiring or defective relay. |
| 1241 | Air Mass Sensor (HFM) | Observe load signal with scan tool. The nominal value is 1.8-2.2 ms when the battery is charged, air conditioning switched off and gear selector lever in position P or N. If the nominal value is not achieved, check voltage supply of air mass sensor, wires and connector. If voltage supply, wires and connector are okay, check air mass sensor. |
| 1242 | A/C Compressor | Code indicates an open or short to voltage or ground in A/C compressor signal wire to DME. Check A/C belt and refrigerant charge. |
| 1243 | Crankshaft Position Sensor | Code indicates an open or short to voltage or ground in crankshaft position sensor wiring, or defective sensor. |
| 1244 | Camshaft Position Sensor | Code indicates an open or short to voltage or ground in camshaft position sensor wiring, or defective sensor or coil(s). |
| 1245 | EGS | Code indicates a short to ground in wiring between EGS and DME. |
| 1247 | Ignition Secondary Monitor | Diagnosis is not available. |
| 1251 | Injector No. 1 (Group 1) | Check injector wiring. Check injector for proper operation and spray. |
| 1252 | Injector No. 2 (Group 2) | Check injector wiring. Check injector for proper operation and spray. |
| 1253 | Injector No. 3 | Check injector wiring. Check injector for proper operation and spray. |
| 1254 | Injector No. 4 | Check injector wiring. Check injector for proper operation and spray. |
| 1255 | Injector No. 5 | Check injector wiring. Check injector for proper operation and spray. |
| 1256 | Injector No. 6 | Check injector wiring. Check injector for proper operation and spray. |
| 1257 | Injector No. 7 | Check injector wiring. Check injector for proper operation and spray. |
| 1258 | Injector No. 8 | Check injector wiring. Check injector for proper operation and spray. |
| 1261 | Fuel Pump Relay | Code indicates an open or short to voltage or ground in fuel pump relay pin No. 3 |
| 1262 | Idle Speed Actuator | Code indicates an open or short to voltage or ground in wiring to idle actuator from DME, or output stage of DME is defective. |
| 1263 | Purge Valve | Code indicates an open or short to voltage or ground in wiring to EVAP control valve, or output stage of DME is defective. |
| 1264 | Lambda Heater | Code indicates an open or short to voltage or ground in wiring to DME, lambda sensor heater, heater relay or air pump relay. |
| 1265 | CHECK ENGINE Light | Code indicates an open or short to voltage or ground in CHECK ENGINE light wiring, or bulb is defective. |
| 1266 | VANOS | Code indicates an open or short to voltage or ground in wiring to VANOS relay or defective relay. |
| 1267 | Air Pump Relay | Code indicates an open or short to voltage in wiring between DME and air pump relay, or defective air pump relay. |
| 1271 | Ignition Coil No. 1 | Code indicates an open or short to voltage in ignition final stage wiring. |
| 1272 | Ignition Coil No. 2 | Code indicates an open or short to voltage in ignition final stage wiring. |
| 1273 | Ignition Coil No. 3 | Code indicates an open or short to voltage in ignition final stage wiring. |
| 1274 | Ignition Coil No. 4 | Code indicates an open or short to voltage in ignition final stage wiring. |
| 1275 | Ignition Coil No. 5 | Code indicates an open or short to voltage in ignition final stage wiring. |
| 1276 | Ignition Coil No. 6 | Code indicates an open or short to voltage in ignition final stage wiring. |
| 1277 | Ignition Coil No. 7 | Code indicates an open or short to voltage in ignition final stage wiring. |
| 1278 | Ignition Coil No. 8 | Code indicates an open or short to voltage in ignition final stage wiring. |
| 1281 | DME Memory | Code indicates a problem in DME memory. Check for a low battery voltage problem and repair as necessary. Erase code and reconnect DME. If code reoccurs, replace DME. |
| 1282 | Code Memory | Code indicates an incorrect code has been set in memory. Erase code and disconnect a monitored component. If code reoccurs, replace DME. |
| 1283 | Injector Output Stage | Code indicates an intermittent open or short circuit to voltage at an injector, injector wiring or defective DME injector stage. |
| 1286 | Knock Sensor Test Pulse | Code indicates an internal pulse was not detected in DME. Check knock sensor wiring and knock sensors. |
| 1444 | No Fault | — |
DIAGNOSTIC FLASH CODES
TROUBLE CODE DEFINITION
| Codes | Affected Circuit |
|---|---|
| 0 | Undefined Defect |
| 1 | Fuel Pump Relay |
| 2 | Idle Speed Actuator (Close) |
| 3 | Injector No. 5 |
| 4 | Injector No. 6 |
| 5 | Injector No. 4 |
| 6 | Fuel Injectors (Output Signal) |
| 7 | VANOS |
| 8 | CHECK ENGINE Light |
| 12 | Oxygen Sensor No. 2 |
| 13 | Oxygen Sensor No. 1 |
| 15 | Ignition Circuit Monitoring |
| 16 | Crankshaft (Pulse) Sensor |
| 17 | Camshaft Sensor |
| 23 | Ign. Coil (Cyl. 4) |
| 24 | Ign. Coil (Cyl. 6) |
| 25 | Ign. Coil (Cyl. 5) |
| 26 | DME Power Supply (B+) |
| 29 | Idle Speed Actuator (Open) |
| 31 | Injector No. 5 |
| 32 | Injector No. 6 |
| 33 | Injector No. 5 |
| 36 | Fuel Tank Vent (Evaporation) Control |
| 37 | O2 Sensor Heater |
| 41 | Air Mass (Sensor) Meter |
| 42 | Vehicle Speed Sensor |
| 48 | A/C Compressor Shutoff |
| 50 | Ignition Coil (Cyl. 1) |
| 51 | Ignition Coil (Cyl. 2) |
| 52 | Ignition Coil (Cyl. 3) |
| 54 | DME Power Supply |
| 57 | Ign. Timing Intervention |
| 62 | Electronic Engine Power Control Signal |
| 66 | Theft Alarm Signal |
| 69 | Knock Sensor 2 |
| 70 | Knock Sensor 1 |
| 73 | Throttle Valve Potentiometer |
| 77 | Intake Air Temp. Sensor |
| 78 | Engine (Coolant) Temp. Sensor |
| 82 | Engine Drag Torque Control Intervention |
| 83 | Automatic Stability Control Intervention |
| 100 | Output Stage (Signal 1) |
| 101 | Output Stage (Signal 2) |
| 200 | DME Control Unit |
| 201 | Oxygen Sensor Control |
| 204 | Idle Speed Increase During MSR Operation |
| 206 | Knock Control Test Pulse |
FAULT CODE IDENTIFICATION (M50)