1999 S70 GLT LPT (vin 56) ETM, MAF or Relay Issue with Codes

johnmal85 · Post by **johnmal85** » 19 Jul 2014, 14:56

I have an intermittent and ongoing issue that has finally become regular just this week. I have had ETM light turn on several times over the course of the past few years. It is usually random and it may be linked to jumping other peoples cars, that I have noticed.

I have replaced the upstream O2 sensor, and the MAF sensor. Also the thermostat and the temp sensor (all aftermarket).

I was driving home from work after jumping someones car for about 40 minutes (I left it running while I troubleshot his 2002 Chevy Blazer that turned out to have a wet air filter suffocating the intake), then drove home. Almost to my exit about 20 minutes after leaving, I lost power entirely to a stall going about 75 mph, and coasted to my exit off the turnpike. I pulled over and yanked the MAF sensor cord off and drove home.

I chalked it up to another quirky electrical issue from charging that persons car, and recharged my battery, cleaned the MAF and cleared the codes. It drove fine to work, relatively, with barely noticeable turbo hesitation, but I chalked it up to the car adjusting fuel trim, etc. On my way home that night, it lost power on the turnpike at around 70 mph, but this time it didn't stall out. I removed the MAF sensor cord again and drove home (I removed it because the car was in limp mode, and that's very dangerous on a highway).

So after two days reading about the issue this is what I have done to begin to diagnose the issue:

Prior to the drive I made sure to clean the MAF with appropriate spray and let it fully dry out. I noticed the ENGINE MANAGEMENT RELAY case was cracked on one side (maybe due to previous owner inspecting the coil), so I removed the relay carefully and noted that two out of the four prongs were black. I also removed the AIR PUMP RELAY and sprayed electronic cleaning spray on both of the prongs and to where the relays plug into the car. I did all of this with the battery disconnected. I let them set for maybe two hours before replacing them in the car. then took my car for a 45 minute drive or so, trying to do a drive cycle as best I could with a few slow downs during the 45 mph portions due to traffic lights. I made sure to turn my car off and on a few times after the drive cycle. I ended it with a nice drive on the turnpike to get some solid speed in. All seemed well.

I parked for maybe ten minutes with the car off, then turned it back on to drive to the parts store. I made a slightly hard left turn with brakes applied and stalled, to my surprise, and barely made my turn with traffic headed towards me. Car started right back up and was having some hesitation, etc. and I noticed some RPM drop when I braked hard or turned steeply. I then popped the A/C back on and while sitting at a stop sign it just plain stalled. It started back up every time it stalled usually pretty easy with a pull or two on the key. Finally I got the check engine light, this was good, because I needed some codes read. After another stall or two during my drive I got my ETM light to come on.

At the shop, OBD-II codes:

P0238 TURBO SENSOR
P0236 TURBO SENSOR
P0103 MAF
P0452 EVAP
P1171 ???

So this is where I am. I have the diagnostic flow chart from XeMODeX and I am not sure if this qualifies as an intermittent problem or not now. It seems to be recreated anytime after a lengthy drive that gets up to high speed. Should I attempt to swap back to my OEM MAF or maybe attempt a ETM cleaning?

Thanks for all of your time and input.

Post by **abscate** » 20 Jul 2014, 07:39

Aftermarket stuff is not recommended for most of the parts you cite. Some of them work, some don't.

Are you still on the original white label ETM ? That has probably given up.

Disconnecting the MAF usually won't get you out of limp mode if it's an ETM issue. My guess is your ETM is on last legs. No loss to try a cleaning of course

johnmal85 · Post by **johnmal85** » 22 Jul 2014, 23:38

I don't know if it is out of form or not, but I can post a similar discussion I've been having in another forum. My car does not continue in limp-home mode with the MAF disconnected.

I have found that the AFTERMARKET MAF is basically dysfunctional, and the STOCK BOSCH MAF is leagues better. It may or may not be throwing a code, without VADIS, I suspect it may actually be TPS turbo pressure sensor fault, that may relate to my cruise control not working all the time (my brake light doesn't come on randomly, so I don't think its the sensor).

With the AFTERMARKET MAF my ETS light would illuminate and the car would enter limp-home mode. It worked decently for about 50 miles, then became bad, and after 1 to 2,000 miles it has degraded into full ETS failure symptoms. When I disconnected it, my car came off of acceleration hard, but left limp-home mode and would drive almost perfectly, minus fuel mileage and unsteady control when coming off gas.

With the STOCK BOSCH MAF, the ETS light has disappeared (without a code or battery reset), and the car drives almost perfect. It doesn't stutter under full acceleration from 2 to 3rd gear getting on the highway, nor does gas mileage seem as bad. It isn't in limp-home mode. Cruise control is still hit or miss, even after replacing the signal stalk with a junkyard part. I suspect a vacuum line or TPS.

Any thoughts? I believe I have a stock ETM, but I haven't checked to be sure. Based on the symptoms, I don't think the ETM is failing, because it is to my understanding that a failing ETM's symptoms will be pervasive even if I disconnect the MAF.

Thanks in advance, and I'm sorry for the slow response. I guess I didn't have the notification settings correct on MVS. Thank you!

johnmal85 · Post by **johnmal85** » 23 Jul 2014, 00:00

When I cite stock ETM, I am not actually sure. I doubt I have a non-yellow sticker as I'm near 170,000 miles. Is there a way I can easily view this without removing the fan, maybe with a camera or a mirror? I know where the ETM is located, but I don't know what this sticker is that I should be looking for... I found a 99 Non-Turbo in the junkyard with an ETM still in it, and it had a GREEN marking on it. Like a paint or marker on it. Is that compatible and does it sounds like something important to note as being green? I can live with the STOCK BOSCH MAF for now, I was just in a hunt for having no CEL. The car ran relatively well as it was... but the hunt for the no CEL, I'm sure you all can agree is a noble hunt! =)

Post by **abscate** » 23 Jul 2014, 05:24

John...thanks for sharing and your netiquette is impeccable...

.you don't have vacuum control on your cruise control, on your 99, it's fly by wire. Since the throttle is now electronic, the Engine control unit (ECU) just moves the throttle electronically when you ask for cruise.

You are probably registering some fault that the ECU is programmed to shut off the cruise function when detected. I actually found something interesting on my 99... After I cleared CEL codes, my cruise would not work until I either cycled the ignition on /off or drove for about 30 minutes.

I am a bit surprised that you can get a fault bad enough to shut off cruise without getting an ETS light.

I'll try snap a pic of the yellow label on my ETM this morning.

Post by **regent** » 23 Jul 2014, 06:42

Just a note here:
With a fly-by wire setup, even if you just run a simple ETM test with VIDA the ECU disables cruise control temporarily until you reset (no MIL or ETM comes on though). I am not sure why but this is how it behaves - probably a safety feature.

johnmal85 · Post by **johnmal85** » 23 Jul 2014, 07:28

Thank you abscate. I have the turbo setup and cannot get to the ETM until the weekend. If I see what the sticker looks like then that might give me an idea where to look.

Regent, that sure is an interesting note. It is very odd how the cruise control works intermittently. One moment its on and the next its gone. After a minute or so I can enable it again. Sometimes it stays on for a while and sometimes I can't even set it at all or for less than a few seconds.

Post by **regent** » 23 Jul 2014, 07:32

Could there be an issue with the control wiring itself (like some dirty button or even an intermittent poor contact or short)

johnmal85 · Post by **johnmal85** » 23 Jul 2014, 11:04

regent, I suspect not, as I replaced it with a junkyard control stalk the other day. My stock stalk had a + Accel button that did not function. With the replacement I still have the intermittent connection or availability, but the + Accel does now work. I suspect the wiring fault would be beyond the stalk if it is a wiring issue. I might have to take a look beyond the covers and maybe see if there is a bare wire or a dirty connector.

abscate, thank you so very much for the pictures. That is a very clear idea of what to expect. I wonder if that yellow tape or paint on the wiring is relevant as well? I shall go take a look under my hood right now.

johnmal85 · Post by **johnmal85** » 23 Jul 2014, 11:22

Okay, it appears that I have the yellow sticker ETM.