PROJEKT36 · WIRING

M43 & M44 engine management

Every used pin of the four-cylinder engine computers: Bosch M1.7.3 on the M43 (316i, 318i) and M5.2 on the M44 (318is). Function from BMW's pin table, wire colour and where the wire goes.

E36 four-cylinders from the 1998 BMW wiring manual; the M42 is not in this manual. On a phone, scroll the diagram sideways.

projekt36.com/wiring/m43-m44-engine-management/

SW blackRT redGN greenBL blueGE yellowBR brownWS white GN/SW = green with black stripe supply / ground of a part shown elsewhere

M43 (M1.7.3): X6000 pins 1–44

0.5 BR/GN fuel pump relay K6301 pin 4 (coil) 0.5 BR idle actuator X6130 pin 1 0.5 BR/GN injector 2 (X6102 pin 2) 0.5 BR/WS injector 4 (X6104 pin 2) 2.5 BR ground X6454 0.5 BR/GE EGS X8500 pin 38 (automatic) 0.5 BR/VI throttle potentiometer X6252 pin 2 0.5 GR/BL air flow meter X6233 pin 5 0.35 SW knock sensor X6241 pin 1 0.35 SW camshaft sensor X6204 pin 2 0.5 WS/SW cluster X16 pin 21, via X20 pin 24 0.5 BR/BL changeover valve Y6131 X6131 pin 1 1.5 GE ignition coil 3 (X6153 pin 1) 1.5 WS ignition coil 1 (X6151 pin 1) 1 RT battery feed X6410 0.5 BR/WS DME relay K6300 pin 85 (coil) 1.5 BR ground X6454 0.5 BR/GN idle actuator X6130 pin 3 0.5 BR/BL injector 3 (X6103 pin 2) 0.5 BR/GE injector 1 (X6101 pin 2) 2.5 BR ground X6454 0.5 BR/VI charcoal filter valve X6120 pin 2 0.5 BR/GN oxygen sensor relay K6303 pin 4 (coil) 0.5 GR/GE air flow meter X6233 pin 2 0.35 SW knock sensor X6241 pin 3 0.75 BR/SW sensor ground, splice X6461 0.35 GE camshaft sensor X6204 pin 1 X6000 DME control unit M1.7.3, pins 1–44 1 Electric fuel pump relay and TR … 2 Idle actuator signal 3 Injection signal 4 Injection signal 6 Ground, injection valve output … 11 Throttle valve position 12 Throttle valve position 14 Component ground 15 Knock sensor signal, cyl. 3 and 4 16 Component ground 17 Fuel consumption (TI signal) 18 Changeover valve 1 24 Ignition signal cyl. 3, terminal 1 25 Ignition signal cyl. 1, terminal 1 26 Permanent positive, terminal 30 27 Activation, DME main relay 28 Ground for electronics and sensor … 29 Idle actuator signal 31 Injection signal 32 Injection signal 34 Ground for remaining output … 36 Fuel tank ventilation valve 37 Activation, oxygen sensor relay 41 Signal, air flow rate sensor 42 Knock sensor signal, cyl. 1 and 2 43 Sensor ground 44 Camshaft signal

How it works

Bosch M1.7.3 runs the M43 (316i, 318i): four coils, sequential injection, an air flow meter with flap, one oxygen sensor with its own heater relay, and the intake changeover valve.

Redrawn from BMW ETM 1210.19 (05/99), standard petrol E36 (316i–328i); diesel and M3 parts are left out.

M43 (M1.7.3): X6000 pins 45–88

0.5 RT/WS fan stage 1 relay K21 pin 5, via X20 pin 8 0.5 SW/BL A/C compressor relay K19 pin 85, via X20 pin 4 1.5 BL ignition coil 4 (X6154 pin 1) 1.5 RT ignition coil 2 (X6152 pin 1) 1 RT/WS DME relay K6300 pin 87, splice X6821 2.5 BR ground X6454 0.5 GN ignition switch 15, splice X6832 0.75 GR/WS throttle pot. X6252 pin 1 / air flow meter X6233 pin 1 0.75 WS/GN diagnostic connector X6002 pin 18 0.5 GR/VI dual temperature switch S36y, via X20 pin 3 0.5 BR/GR EGS X8500 pin 51 (automatic) 0.5 BR/SW selector lever switch X511 pin 7 (automatic) 0.35 GE crankshaft sensor X6203 pin 1 0.35 SW crankshaft sensor X6203 pin 2 0.5 GE oxygen sensor X6200 pin 2 0.5 SW oxygen sensor X6200 pin 1 0.5 SW/WS cluster X17 pin 2, via X20 pin 14 0.5 SW cluster X16 pin 20, via X20 pin 20 0.5 GR/SW air flow meter X6233 pin 3 0.5 GR/VI air flow meter X6233 pin 4 0.5 BR/RT coolant temp. sensor B6232 X6232 pin 3 0.5 SW/VI EWS II X1659 pin 4, via X20 pin 7 0.5 SW/GR pressure switch B8y pin 4, via X20 pin 5 0.5 VI/GR IHKA X1527 pin 10, via X20 pin 6 0.35 SW EGS X8500 pin 85 / ASC (CAN low) 0.35 GE EGS X8500 pin 86 / ASC (CAN high) 0.5 WS/GE diagnostic connector X6002 pin 15 0.5 WS/VI diagnostic connector X6002 pin 17 X6000 DME control unit M1.7.3, pins 45–88 46 Relay activation 48 A/C compressor shutdown 51 Ignition signal cyl. 4, terminal 1 52 Ignition signal cyl. 2, terminal 1 54 B+ voltage 55 Ground, ignition 56 Ignition, terminal 15 59 5V component supply 60 Programming voltage 62 Signal, water temperature above … 64 Ignition timing intervention 65 Drive range P/N 67 Crankshaft signal 68 Component ground 70 Oxygen sensor signal 71 Component ground 73 Vehicle speed signal 74 TD signal 76 Idle CO potentiometer 77 Intake air temperature sensor 78 Engine temperature sensor 81 Vehicle immobilization 82 Switch for A/C compressor 83 Air conditioning ON signal 85 CAN-LOW 86 CAN-HIGH 87 RxD diagnostic link 88 TxD diagnostic link

How it works

The DME switches fan stage 1 itself (pin 46) and reads the 80 °C contact of the dual temperature switch (pin 62).

Redrawn from BMW ETM 1210.19 (05/99), standard petrol E36 (316i–328i); diesel and M3 parts are left out.

M44 / 318is (M5.2): X6000 pins 1–44

0.5 BR idle actuator X6130 pin 1 0.5 BR/GE injector 1 (X6101 pin 2) 0.5 BR/WS injector 4 (X6104 pin 2) 2.5 BR ground X6454 0.5 SW/VI EWS II X1659 pin 4, via X20 pin 7 0.5 SW/GR pressure switch B8y pin 4, via X20 pin 5 0.5 BR/RT intake air temp. sensor X6205 pin 1 0.5 GR/BL air mass meter X6217 pin 2 0.5 GE oxygen sensor X62001 pin 4 0.35 SW crankshaft sensor X6203 pin 2 0.5 GE camshaft hall sensor X6209 pin 2 1.5 GE ignition coil 3 (X6153 pin 1) 1.5 BL ignition coil 4 (X6154 pin 1) 1 RT battery feed X6410 0.5 BR/WS DME relay K6300 pin 85 (coil) 1.5 BR ground X6454 0.5 BR/GN idle actuator X6130 pin 3 0.5 BR oxygen sensor X62001 pin 2 0.5 BR/BL injector 3 (X6103 pin 2) 0.5 BR/GN injector 2 (X6102 pin 2) 2.5 BR ground X6454 0.5 SW/BL A/C compressor relay K19 pin 85, via X20 pin 4 0.35 SW knock sensor X6240 pin 3 (cyl. 3–4) 0.5 BR/VI throttle potentiometer X6252 pin 2 X6000 DME control unit M5.2, pins 1–44 2 Idle actuator signal 3 Injection signal 4 Injection signal 6 Ground, injection valve output … 10 Vehicle immobilization 11 Air conditioning signal 16 Temperature signal 17 Signal input 19 Oxygen sensor signal 20 Component ground 21 Camshaft signal 22 Ignition signal, terminal 1 23 Ignition signal, terminal 1 26 Permanent positive, terminal 30 27 Activation, DME main relay 28 Ground for electronics and sensor … 29 Idle actuator signal 30 Component ground 31 Injection signal 32 Injection signal 34 Ground for remaining output … 36 Air conditioning ON signal 40 Knock sensor signal, cyl. 3 and 4 44 Throttle valve position

How it works

Bosch M5.2 runs the M44 in the 318is: four coils, sequential injection, a hot-film air mass meter, a camshaft hall sensor and one heated oxygen sensor.

Redrawn from BMW ETM 1210.20 (05/99), standard petrol E36 (316i–328i); diesel and M3 parts are left out.

M44 / 318is (M5.2): X6000 pins 45–88

0.5 GR/VI air mass meter X6217 pin 4 0.5 SW oxygen sensor X62001 pin 3 1.5 WS ignition coil 1 (X6151 pin 1) 1.5 RT ignition coil 2 (X6152 pin 1) 0.5 GR/WS throttle potentiometer X6252 pin 1 1 RT/WS DME relay K6300 pin 87, splice X6821 2.5 BR ground X6454 0.5 GN ignition switch 15, splice X6832 0.5 RT/WS fan stage 1 relay K21 pin 5, via X20 pin 8 0.5 BR/BL changeover valve Y6131 X6131 pin 1 0.75 WS/GN diagnostic connector X6002 pin 18 0.5 BR/VI charcoal filter valve X6120 pin 1 0.5 BR/GN fuel pump relay K6301 pin 4 (coil) 0.5 GR/VI dual temperature switch S36y, via X20 pin 3 0.5 VI/GR IHKA X1527 pin 10, via X20 pin 6 0.35 SW knock sensor X6240 pin 1 (cyl. 1–2) 0.75 BR/SW sensor ground, splice X6461 0.5 BR/RT coolant temp. sensor B6232 X6232 pin 3 0.35 GE crankshaft sensor X6203 pin 1 0.75 BR/RT ASC, via X20 pin 9 0.5 SW cluster X16 pin 20, via X20 pin 20 0.5 WS/SW cluster X16 pin 21, via X20 pin 24 0.35 SW EGS X8500 pin 85 / ASC X1175 pin 18 (CAN low) 0.35 GE EGS X8500 pin 86 / ASC X1175 pin 17 (CAN high) 0.5 WS/GE diagnostic connector X6002 pin 15 0.5 WS/VI diagnostic connector X6002 pin 17 X6000 DME control unit M5.2, pins 45–88 45 Component ground 46 Oxygen sensor signal (-) 49 Ignition signal, terminal 1 50 Ignition signal, terminal 1 53 5V component supply 54 B+ voltage 55 Ground, ignition 56 Ignition, terminal 15 57 Auxiliary fan ON activation 58 Changeover valve signal 60 Programming voltage 61 Signal, fuel tank ventilation 63 Relay activation, terminal 85 68 Signal, water temperature above … 69 Air conditioning ON signal 70 Knock sensor signal, cyl. 1 and 2 71 Sensor ground 74 Coolant temperature signal 78 Crankshaft signal 79 Wheel speed signal, rear right 80 TD signal 83 Vehicle speed signal 85 CAN-LOW 86 CAN-HIGH 87 RxD diagnostic link 88 TxD diagnostic link

How it works

Pin 79 takes a wheel speed signal from the ASC; 85 and 86 are the CAN bus to the ASC and the EGS.

Check on your car

  • The pin table calls pin 83 "vehicle speed signal", but the schematic runs it to the cluster's fuel consumption input (X16 pin 21, white/black). Drawn as the schematic.

Redrawn from BMW ETM 1210.20 (05/99), standard petrol E36 (316i–328i); diesel and M3 parts are left out.

Reading the wire codes

BMW labels every wire with its size and colour, for example 2.5 SW/GE: 2.5 mm², black (schwarz) with a yellow (gelb) stripe. Connectors are numbered X…, followed by the pin. The wires in these diagrams are drawn at relative thickness, so the 25 mm² battery cable stands out from a 0.35 mm² signal wire.

Codes used here: SW = black, RT = red, GN = green, BL = blue, GE = yellow, BR = brown, WS = white.