SES at Cold Start-up

[gvt]

For the last month or so I am getting the SES light occasionally after starting the truck in the morning. The truck is in the garage and it has not been plugged in. It hasn't been too cold lately. The SES goes out after a trip or two. After a couple morning starts without the SES it comes on again. The truck seems a little down on power and a little extra rattle when the SES is on, but no noticable extra smoke or drop in mileage. Have any of you folks experienced this? Any help would be greatly appreciated. Thanks

[GARY PAGE]

Does it miss on start up for a bit?

[gvt]

It maybe cranks a second longer and/or misses once or twice while cranking. When it is started it does not miss. Thanks again!

[gmctd]

If you'll check for any DTC codes, and post them here, determining nature of failure(s) will be easier.

[Simzie]

I had the same problem with my 98"...retrieved the trouble code and it was in the glow plug circuit, cant remember the code offhand. I elected to replace the glowplugs with some faster heating plugs from J.K. these went fine for about a week and then i got the code again. Thats when I went nuts with the test light and the volt ohm meter testing for voltage at the glow plugs...Nothing! turned out to be the controller relay towards the rear of the motor on the drivers side. I replaced it and have'nt had a lick of trouble since...about three months. I paid about $54.00 for this controller from a friend who has a parts store specializing in delco parts, I dont think its available anywhere else except for the dealer....If you have a lot of miles on your glow plugs 50,000 or more, I would recommend replacing them, but definetely check for voltage at the plugs while the glowplug light is on, if no voltage check the heavy lead to the controller, if its good before the controller and not after(wires leading to glowplugs) while the glowplug light is on, replace it or atleast check the connections. I believe the pcm can determine if the contact fails within the relay by a micro-volt signal sent back to it from the controller/relay thus triggering a ses light, or atleast a failure of the signal would cause the light...Sorry Im rambling on, hope this is some good info for you...good luck Scott

[gvt]

Thanks for the info Scott!
I'm hoping to have time to investigate before resorting to the dealer, but my work schedule may not allow. Sound like a good place to start though. I am definately overdue to replace the glowplugs, 123,000 miles - ouch! The truck sits outside all day while I'm at work and it always starts just fine. I guess it's time for a little TLC. Thanks again!