My car popped up the Service Engine Soon light the day after i had v.38 flashed. It went out in a couple days & stayed that way for 2000 miles. It came on last weekend, cruising steady @ 75 mph ~3200 rpm. Went out in a couple of days. Thought it might be a fluke, bad gas, whatever. Got out on the highway again today. Same speed, same spot in the road - SES on again! Got gas elsewhere the last time, so I don't think it's that. Car is pullied w/ Ryephix #2. I generally don't run it hard or into upper rpms. Anyone else experienced this?

UPDATE:
Problem may be loose clamp. Will update when clamp replaced...

UPDATE:
New clamp - no change...

 

Until you pull the code that triggered the SES light, all you're doing is speculating. The light comes on for a reason and you should have it checked out. My car is similar to yours in mods for the last 20K miles. Each time the SES light has come on it has been for a specific, identified problem that was fixed by my dealer. They have never questioned my mods or given me a hard time about fixing the car under warranty.

Take it in and get it checked out. The code will still be there, even if the light goes out.

 

Are you sure you got v.38 and not v.39? The reason I ask is that my SES light started coming on after I got v.39 due to it being more sensitive about the thermostat and coolant temperature.

Stop by Autozone/Advance Auto and have them read the code - but don't have them clear it. If its a P0128, it's due to the new software and old thermostat. That will require a dealer visit to fix the problem. At first I thought it was a fluke and I turned out the light. Three times in fact. Then I got tired of fooling with it and made a service appointment.

I had the dealer replace my t/stat a week ago and the SES light hasn't shown up since then.

 

P0171 - System Too Lean (Bank 1). Is it possible that a bum sensor is falsely triggering the code?

 

The other frequent SES is a Code P0128, which apparently means some sort of thermostat fault. I log the coolant temp with a Davis CarChip E/X and the fault occurs every couple of days since the dealer flashed firmware for the recall. When SES comes on, the coolant temperature is perfect -- in the 190-200 deg range. Fortunately the Davis widget lets me reset the SES light.

 

Consider yourself lucky, my thermostat was replaced because of "P1028 "fault code. One week later the SES light came on again. I haven't brought it back yet. It's been two weeks now.

retroom

 

I'm also having SES light issues after V 39 for a few months now. SES comes on for 3-5 days or so, goes off for day or two, then on, week later its off.....

Just bought carcode from Alex Peper http://www.obd-2.com/ that Helix used when he was in Hawaii. Cleared codes but SES comes back on in few days. Have to pull the codes to see which it is. Annoying- never had issues before V 39.

 

I'm still getting a P0128 every couple of days. It does not reset itself, but I can clear the fault with the Davis CarChip EX. The Davis widget tells me the precise time that the P0128 SES happens, and I have it logging things like coolant temp. For me, it seems that EVERY TIME P0128 shows up, the engine is up to its full 190-200 deg temperature. So, despite the prevaling wisdom of a bad thermostat, my thermosts seems to be doing just what it is supposed to do.

 

My P1028 code came on after I loaded MTH, before my car ECU had been otherwise flashed. Dealer replaced the thermostat...SEL light STILL comes on..coolant was tested and ok...

 

Yep. Mine always came on with the engine fully warmed up too.

But since the dealer replaced the thermostat, I haven't seen the SES light again (knocks on wood...)

 

Hmmm... I have a very similar problem: lately my car is throwing the thermostat code and turning on the SES light now and again. I reset the code... everything is fine until next time. I ran v38 ECU code for a very long time (6 months) with the Superchips ECU mod and never saw this, even once, until I unloaded Superchips and replaced it with MTH... since then I've seen it happen a three times in just a few weeks.

Could this somehow be related to the MTH mapping???

Dan

 

Dan,

I would suggest that yes, this is the result of the MTH mapping if that is the only variable that has changed, causing the SES light to come on. I don't think that the two symptoms are independent at all.

To diagnose poperly, reload the superchips map and run with that for a week. If the SES light fails to turn up, you have your answer in the bag

Cheers,

Henry

 

Yep Dan, I do wonder if it has to do with MTH, but not everybody getting this problem has MTH, right? Some people only have the most recent OEM flash?

So maybe it is something to do with "tweaking the settings and inadvertantly writing code that in someway alarms the current sensors or something? My thermostat was replaced and the light still came back on...car running great though...gotta go back into the dealer but

keep us updated if you take off MTH....

 

I got it post 39.x, pre-MTH.

Not saying that the MTH might not aggravate it, but it's not the only cause.

 

I'm sending mine into the dealer in a week or so to get the 10K service and (hopefully) the v40 ECU code for the recall. Guess I'll mention it to them, and maybe leave the SES light on for them next time it happens. I'll have to reload MTH after the new dealer flash, so maybe I'll delay that a bit and see if they do a good fix for the thermostat error (gotta wait for updated v40 files from Franz anyway).

Oddly enough, the light seems to come on under almost exactly the same circumstances each time for me, too. The car sits at an airport for a week (indoor unheated garage, 50 degrees or so) under a car cover. Fire it up, driving conservatively as I leave the garage/airport area and the car warms up. Hit the freeway in about 10 minutes (car fully warmed up) and after a few minutes at 70-80 MPH (with maybe a brisk acceleration through the gears to that speed ) the SES light trips. Continue home, reset the code, and all is well until the next time. Doesn't seem to do it every time, though... go figure.

BTW... anyone know how you download a new version of Cartune from MTH without paying for it again? I see the version on the web site is newer than mine, but even after logging in there doesn't seem to be a way to get it.

Dan

 

Exactly. it seems to be happening to people who either got a recent manufacturer ECU upgrade, or MTH upgrade...in either case, I'm wondering if the "fine tuning" is somehow triggering sensors that will be found obsolete with the new version?
(Somebody who really knows this stuff and understands what I'm saying, please put me straight!)

 

GoodOlDan,

Check your PM.

 

So what's the verdict on this fault?

My tire pressure and DSC lights came on today...I checked and the tires were fine, and when I restarted the car, they were gone, but I checked the codes anyway and also got the P0128 Coolant temp thing...no MTH here and I think I might have the v40s/w...

L

 

Haven't gotten it looked at , but I 've found a workaround. If I cruise in 5th ~ 3850 RPM as opposed to 6th ~ 3200 RPM, the light doesn't trip. And my mileage is actually better! Bizzare, no?

 

Any update on your problem?