SES light - no go

[Barc]

Today my 01 D/A with 80,000 kms pulled a fast one on me - went to take off - pushed the pedal - no go - tach went to about 1800 rpm and wouldn't shift - motor sounded fine - if I feathered back on the pedal it would shift and take off but if I held the pedal down more than 1/4 it would die out - even downshifted a couple of times on me - sending the tach to 3000 rpm. SES light came on - I called the dealer right away - he said bring it in when you get to town and we'll check it out - they plug the TAC II unit in and it brings up ZERO transmission codes - but it does bring up large (massive) fuel leak??? But there was definetly no leaking fuel - I have replaced the fuel control module and 1 injector but this seems to be different - service advisor was going to do some snooping around for info - I thought I might as well go to the EXPERTS here on the DIESEL PAGE!! :D Anyone have any ideas???? Thanks

[TBC]

That happen to me in the mountains with my TT in tow. I was using my aux tank which was down about halfway between 1/4 and empty. I was up and down hills, etc. I had felt the truck hesitate for a second once while pulling a hill but it was OK until I had to stop for construction and then the SES light came on and I could only get about 15 MPH and no shift. I switched from my aux tank right before I stopped and the SES lite coming on. I got to the top of the hill and slowed to make a turn into a church parking lot and then punched the accelerator and it took off like a rocket and caught me totally by surprise. It ran fine after that but the SES lite was still on. I checked the owners manual and it talks about it coming on if you are low on fuel. I took it to the local dealer and they said I would have to come back the next morning since it was so late in the day. Naturally I had to shut the truck off 3 or 4 times for that evening and lo and behold like the owners manual said it reset the lite. I took the truck in the next day and the code showed a massive fuel leak but of course it was not leaking. After discussing it with the service folks we concluded that the aux tank fuel out line apparently uncovered enough with the motion of the truck to cause it suck air and then computer thought it was a leak since there was no fuel and the low level light was not on.

Perhaps foaming in the tank at high altitude and the truck motion caused and inaccurate fuel level indications and I should have switched the tank before I did. I normally would wait until the low level lite came on before I switched. I don't do that any longer. When it indicates about 1/8 tank I switch. Maybe this will help to understand why yours came on. I have driven about 5000 or more miles since then and it never has come on again and I have had no problems.

[SoCalDMAX]

I'm thinking along the lines of plugged fuel filter. If the filter won't pass fuel, you'll get low fuel rail pressure, the ECM thinks there's a massive leak, SES light comes on, and it won't shift or rev over 2,000rpm.

It happened to me a few weeks ago, very suddenly. Changed fuel filter and all was cured. The old filter only had 11,500mi on it and did not look dirty.

Good luck, Steve

[hoot]

Didn't someone once mention that using aux tanks creates an issue.

" A word to the wise about running the fuel down until the LOW FUEL light comes on. I did that on my aux tank and had done it at home in relatively flat terrain without a problem. I got into the mountains and was waiting for the light before switching and actually the gage indicated I was a several miles before switching. This was based on previous experious of knowing where the light came on. Well in the mountains and possibly some foaming caused the gage to indicate fuel was OK. I had a burp in the engine and all was well for a while longer and after about 2 or 3 miles the SES light came on. I had to stop for construction and when I started out after they let us go my truck was in limp mode and trying to pull a long grade with my trailer. That is no fun. When I topped out and turned into a parking lot I let off throttle and then added throttle and when I did the engine was back to normal and it was a real surprise when it happened. The SES light stayed on and I went to the nearest Chev dealer in Durango, CO and they couldn't look at till the next day. After about 3 or 4 stop and start eng. the light went off. The code showed a large fuel leak. The owners manual says that if you get low on fuel it can cause the SES light to come on. I suspect that is exactly what happened. It sucked some air. I never let it get that low again and have not had a problem."

From....
http://forum.62-65-dieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=3&t=003573&p=

[Barc]

Thanks for the replies guys! My dealer suggested changing my fuel filter but it was done at the last oil change (8,000km ago) so I didn't have them do it!!! Maybe I got a bad filter?? I put on 200 km per day and fuel up every morning just in case I have to put on more kliks so that isn't an issue - nor is the aux tank - I don't have one! The truck has run flawlessly ever since that day - no hesitation or SES light at any time - there is another D/A from the same dealer that is having similar problems - they did change the fuel filter on it with identical results 7-8 days later?!! I'm not sure what it is - I'm just gonna keep driving it like I stole it!!! Thanks again!!! :D

[TBC]

Hoot

That was from my post back in June. That was the same incident that I reponded to Barc's message with. What a memory. I can hardly remember an hour ago sometimes. Some of this stuff does stick and comes back when somebody asks about it.

I am glad that I have not had a repeat of that incident. Truck runs great. I am just ready to hook up and go back to the mountains. Can't get enough of driving that big baby.

I had the tires rotated Saturday and the young man changing them says excuse me for saying this but that is one big a** truck.

We are gaining ground on the others. In the plant where I work we have several parking lots and the one I park in is the smallest one and there are 4 GMC and Chev Duramax's in it on a daily basis. I saw one in one of the other lots also. I have seen more Duramax's on the road in the past month than ever. They are getting more common.

TBC