Smart 450 glow plug error

[mtiqbal 0]

I have a smart 450 diesel. Since yesterday, it is giving p0380 glow plug/ heater circuit A  error code and engine light is on.  Glow plug light turns on at start but that goes away in a minute.  So far car starts without any issue.   It is an old car. Can I keep driving this with this error?  When would this not start and I have to replace all three glow plugs?   Thanks 

[Smart42 26]

Yes, you can drive it, but starting will become harder when it gets colder. The plugs are only $17.

[mtiqbal 0]

Do I need to replace just glow plugs or control relay too?

[Willys 747]

Open up the relay and see what he connections or blades are like, some get hot spots and need a slight sanding to c lean them up....or you could buy a new one...lol.

 

[mtiqbal 0]

16 hours ago, Smart42 said:

Yes, you can drive it, but starting will become harder when it gets colder. The plugs are only $17.

 

 

My error code is " p0380 glow plug/ heater circuit A ". What does circuit 'A' means?  Does that means glow plug number 1 is faulty?  Is that right most glow plug?  Thanks

[Smart42 26]

Not 100% sure what the circuit A means, but you are probably right about it being cylinder one. I always assumed cylinder #1 was the most left, though. You can check the plugs without removing them if you have a volt meter. Undo the bracket holding the fuel lines on the right side, wiggle the cable tray up and back so you can see all the glow plug connectors. You can pull them off with needle nose pliers. Grab the tip of the glow plug with your pliers and measure resistance from the glow plug to ground (engine block).  I have always replaced them as a set figuring that if one goes the others will likely follow soon.

Removing them requires a deep 10mm socket with an extension and you have to be careful not to snap them off by applying too much force. If you do you will need to pull the head.  I sprayed mine with penetrating oil for a few days with a warm engine before attempting to remove them. Once they turn a bit wiggle them back and forth with more lube. Once out consider reaming the chamber to remove carbon deposits around the tip of the new plug. Tolsen had a nice write up how he made one from an old plug and drill bit. I made a similar one I can lend you if you are willing to pay postage both ways.

[mtiqbal 0]

On 6/6/2022 at 0:48 AM, Smart42 said:

Not 100% sure what the circuit A means, but you are probably right about it being cylinder one. I always assumed cylinder #1 was the most left, though. You can check the plugs without removing them if you have a volt meter. Undo the bracket holding the fuel lines on the right side, wiggle the cable tray up and back so you can see all the glow plug connectors. You can pull them off with needle nose pliers. Grab the tip of the glow plug with your pliers and measure resistance from the glow plug to ground (engine block).  I have always replaced them as a set figuring that if one goes the others will likely follow soon.

Removing them requires a deep 10mm socket with an extension and you have to be careful not to snap them off by applying too much force. If you do you will need to pull the head.  I sprayed mine with penetrating oil for a few days with a warm engine before attempting to remove them. Once they turn a bit wiggle them back and forth with more lube. Once out consider reaming the chamber to remove carbon deposits around the tip of the new plug. Tolsen had a nice write up how he made one from an old plug and drill bit. I made a similar one I can lend you if you are willing to pay postage both ways.

 

 

Thanks a lot Smart42:   I received 3 new glow plugs today. I took out the first one out (right most one). A multi-meter showed open circuit. I replaced that with a new one. It was simple task. I only need a 10mm deep socket. I cleared the code. Engine light is gone and not more glow plug light.  This indicates " p0380 glow plug/ heater circuit A"  error code refers to right most glow plug.  I decided to replace other two glow plug as needed. (I have two more new glow plugs). Thanks for all your help.

[Willys 747]

IF you drive it in the colder months, I'd change them all while it's warm.....Murphy always comes a calling when you least want him to...IMHO.
Murphy's Law.....It'll always break when it least convenient and when you least want to work on it.....lol

 

[Mjolinor 91]

I hope you put copper grease on it before putting it in because if you did not then that two minute job can turn into a nightmare with head off and drill to get the old one out.