Technical Ducato glow plug relay numbers

[Hulk86]

I have a work van is Fiat Ducato 2010 2.3JTD 120 (IVECO engine) it has been a nightmare lately because I had a issue with start up, when the glow plugs warm it starter but sometimes it refuse to start and leave like 20 minute later and it start!
I have been fit a new fuel filter, new glow plugs, new fuel pump from the tank (high ohms is faulty with motor make a terrible noise) still had the same issue and I have been diagnostic to find a no faulty code, the injector pump and the injectors are function well by chart graph on MultiECUscan.

I felt is the last chance is try to replace a new glow plugs relay which is location on passenger side near the headlamp.

I have been look at it the relay, the numbers printed has worn are hard to reading. I thought it would be a easier to find only one relay for 2.3 but it wasn't there are two types of relay with different codes for 2.3 engine


why are those two relay have different codes? there is only one engine 2.3 it should be one type of relay


What will happen if I fit wrong relay?

 

[Anthony489]

Hi Hulk89

I don't think the glow plugs and their controller ("relay") are the cause of your starting difficulties. The ECU only asks the glow plugs to work if the engine is colder than about 9 degrees C. It would probably start OK without glow plugs down to a few degrees C, but might be a bit lumpy to begin with and give white smoke till it warms up a bit.

For the sake of completeness, here's how the glow plugs work for a Ducato of 2009 vintage. Later engines with better emissions standards may additionally use the glow plugs for periods other than starting, I have no information about how those systems differ.


The glow plug controller behind the nearside headlamp has two sections inside. One is a conventional mechanical relay, which switches on the high-current feed (about 50 amps) to the glow plugs when told to do so by the ECU. The other section is an electronic chip, which individually monitors the current drawn by the four glow plugs. If any current is too low (burnt out glow plug), it sends an error signal to the ECU. If any current is too high (faulty or shorted glow plug) it quickly re-opens the relay and sends an error signal to the ECU. From this you can see that the GP controller isn't very "clever", all it does is switch on and off when told to and send back one type of error signal if any currents aren't right. All the decisions about when and how long to activate the glowplugs is done by the ECU.


If the ECU receives an error signal back from the GP controller, it stores a P0683 error code. The next time the engine is started, the glow plug warning light ("yellow coil") will flash for about 10 seconds after startup. If you don't get another error from the GP controller, e.g. the weather warms up and it's not being used, after 5 or 6 engine starts the warning light will no longer flash. However the P0683 code stays logged until it is cleared.

I expect your GP controller is made by Bosch. The part numbers on Bosch items supplied to production lines seem to sometimes differ from the part numbers Bosch use for replacements, even if the part is identical inside. So reading a number from a part fitted in the factory may give something different than checking the required part number from a dealer.

To remove the GP controller, take the plastic cover off the fuse box on the RHS of the engine bay to give more clearance. Lay some cardboard over the top and take off your watch to avoid danger from short circuits, or disconnect the battery if you want to do it by the book. Reach in between the fusebox and the headlight and you should just be able to pull out the big blue plastic locking tab and pull the connector/loom down from the GP controller. Finally remove the single big hex head self tapper from the inner wing to release the GP controller.