Glow Plug - Wiring Diagram
Before we start with the new topic, let's look at the first video referred to the previous page, where the problem of
glow plugs is addressed by competent side, namely their expansion without demolition.
The video above shows the practical example of how long may last the afterglow in contrast to preheating. Where manufacturer Beru even differentiates the actual starting phase. With regard to the workshop we want
to look especially at the second and third phase (picture below).
According to the wiring diagram of the control unit for the glowing system, four individual cables with 1.5 or 2.5 mm2 lead to the 4 glow plugs. The control unit itself receives plus current via a 6 mm
2
line and a 50A fuse. At 1 ohm of resistance per glow plug so the current adds to about 4 * 12A.
| 1 - 4 | Glow plugs 1.-4. Zylinder |
| 5 | Controller - Motormanagement |
| 6 | Controller - Glow time automatic |
| 7 | Supply line 6 mm2, fuse 50 A |
| 8 - 9 | Glow initialization + feedback |
| 10 | Relays of small and big heating capacity |
This symbol is also very important for the glowing system. Two lines lead from the control unit for the unit to that for the engine management. On the one hand it operates the glowing process and on the other hand it
get fed back. The functions of the glow plugs are monitored and in case of defects the MIL indicator light is switched on.
It goes even further. If you have not used the car for too long and the battery has discharged, the MIL can light up even after charging. It then reports too little energy for the afterglow and incidentally also for the electrical
fuel support. Late consequences of a harmless error. Who wants to help himself without a workshop, buys an OBDII connection with deletion function.
In addition to the mass, there is still a line to the two relays for small and large heating power. This means the necessary because of the high engine efficiency electrical auxiliary heater in the cooling system, which
should remain switched off during the glowing time in order not to burden the electrical supply unnecessarily high. Luckily, that does not belong to the monitoring tasks of the MIL indicator light. 02/18
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