Updated 3/11/2003
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| 35 pin L - Jetronic |
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Seen into the female connectors.
| 1. Ignition coil - (from tach) | 19. No connection |
| 2. Throttle switch, idle (short wire on switch) | 20. From AFM pump
contact (also to Combo relay 86b +) engine running |
| 3. Throttle switch, WOT (long wire on switch) | 21. No connection |
| 4. Pin 50 via main relay | 22. No connection |
| 5. Earth connection for coolant sensor (G100) | 23. O2 sensor shield (gnd) (NC on non lambda) |
| 6. Air flow sensor (0 volts) | 24. O2 sensor (green wire) (NC on non lambda) |
| 7. Air flow sensor signal (0 - 7.5V) | 25. No connection |
| 8. Air flow sensor reference ( 7.5V) | 26. No connection |
| 9. Air flow sensor +12V (joined to pin 12 for high altitude) | 27. Air flow sensor air temp. |
| 10. Combo relay, pin 88a (ignition on) | 28. Ground for combo relay 85 (528i) |
| 11. No connection | 29. Ignition on from combo relay 88b (528i) |
| 12. High Altitude (non-lambda units only | 30. Injector 5 |
| 13. Coolant temperature sensor | 31. Injector 6 |
| 14. Injector 4 | 32. Injector 3 |
| 15. Injector 1 | 33. Injector 2 |
| 16. Earth connection (G99) | 34. Auxiliary air valve - , bimetal |
| 17. Earth connection (G99) | 35. Earth connection (G99) |
| 18. Throttle switch + (common to idle and WOT) |
528i Combo Relay Pinout
| Pin | Wire size & color | Signal | Type I/O/P/G* |
Pin | Wire size & color | Signal | Type I/O/P/G* |
| 86a | 1.5mm bk/yl | start signal from igntion switch (starter solenoid) | I | 86 | 1mm wt | starting (cold start valve and ecu) | O |
| 88y | 1.5mm gn/yl | from fuse #1 (16 amp; fuel pump supply) | P | 88d | 1.5mm gn/vl | to fuel pumps | O |
| 85 | 1mm wt | relay coil gnd from ecu | G | 86c | 1.5mm gn | start run bus from ignition switch 15 (not fused) | I |
| 88a | 1mm wt | ignition on (switched by start/run bus) | O | 88b | 2.5mm wt | +12V power to injectors 4-6 | O |
| 86b | 1mm wt | engine running | I | 88e | 2.5mm wt | +12V power to injectors 1-3 | O |
| 88z | 4mm rd | battery +12V (not fused) | P | 88c | 1mm wt | +12V for cold start valve | O |
*I=input O=output P=Power G=ground
Engine Connector Pinout
Pin |
Wire color |
Signal |
Type I/O/P/G* |
Pin | Wire color |
Signal | Type I/O/P/G* |
| 1 | 1.5 bk/yl | Starter solenoid voltage (+12 when cranking) | O | 5 | 1 bk | Coil negative terminal to tach and L-jet ECU pin 1 (single female connector near ecu socket) | I |
| 2 | 1.5 gn/yl | Start/run bus through fuse 1; To terminal 88y combo relay (to aux air valve 88c and fuel pump88d when cranking ) |
P | 6 | bn/wt | temp guage sensor | I |
| 3 | 1 blue | Alt warning light to alt - also supplies
field coil voltage through warning light bulb to allow charging. +12V when car running |
I/O | 7 | bn/gn | To oil pressure switch (grounded when no pressure) | I |
| 4 | 1.5 gn | Start/run bus - +12V when key is in run position |
O | 8 | gn/violet | Power to fuel pumps | P |
*I=input O=output P=Power G=ground; all with respect to fuse box.