Glow Plugs Not Working

I have a 1998 TDI 1.9
I've check the relay wiring everything is good there. I then went to the temp sensor and check for the references volts coming from ECM and I'm getting 4.98 volt. When I unplug the temp sensor everything works. The glow plugs stay on for max. Time. What is going on?

Thank You for any and all help........

What do you mean? Sounds like things are working properly, when it is about 40*F or higher out, the glow plugs do not pre fire before starting the enigne.

If they aren't coming on long enough, get someone with a vag-com to ask the engine comptuer what temp it is seeing from that sensor.

-J

From your previous post, you have apparently replaced the temp sensor and at 22°F you can't get longer than 1 second of glow plug time. Since you can disconnect the temp sensor and get long glow plug timing, only two likely causes exist. First, the replacement temp sensor is defective or more likely, the replacement temp sensor is the wrong part number. There are different sensors and they have a color code (some are blue and some green, if I remember correctly). You better double check and see it the replacement temperature sensor is the correct one.

You can search for a thread that describes how to change glow plug time using VAGCOM. Wingnut has a "how to" on the subject.

First let me thank you for any help you can give me....
I don't have a vag-com software but I do have something call digimoto software that lets me see what the ECM is seeing for a temp. If the garage is 54 deg. ECM is seeing 58 deg.
I maybe wrong but that reading is within range.
I'll let the car sit overnight an check in the morning and see if the temp. is the same on both garage an eng.

Maybe this will help. If you check each glow plug you can see if it is the glow plug is bad or if it is the harness. You will need a voltage tester. Check the glow plugs for resistance. It should be between .5 - .8, you will see a huge difference in the reading if the plug is bad. Next you will need to crimp the glow plug harness wires. You will hear a cracking sound when you do this but it will ensure you have good harness contact with the glow plugs. Hope this helps.

i have had my 'check engine light' come on and after being vag-com'd/1552'd it indeed is (are) the glow plugs/harness. i am going to order the glowplugs here on tdiclub.com and if needed, the harness via my contact at my local dealership.

i am not sure what the glowing light on your dash means.

perhaps if you have access to get you car vag-com'd/1552'd you'll have your answer.

Does that mean "I like noodles and rice"?

frerk said:

Does that mean "I like noodles and rice"?

Click to expand...

not really, Frerk, in roman letters, it's chotto matte kudasai, which translated from japanese to english is "please wait a while"

i was trying out a new keyboard layout when i posted that reply.

anywhoots, for the original poster, it prolly means time for new glow plugs and/or harness.

keep us informed of your findings!

If Your Not Going To Be Helpfull Please Dont Reply And Waste My Time........