ETM/ETS: ModuleMaster vs. XeMODeX

[precopster]

You can also reference the MAF at idle by checking for a certain voltage at one of the pins. Not certain which pin and what the reading should be. 1.4 volts seems to ring a bell.

[bronson75]

I took out the ETM this afternoon to clean it, put it back in, and it started right up. Idle varied a tiny bit (10-20rpm), I let it warm up for a while, shut it down, and it started again well.
The wife took it to the store, and she had gotten about 2 blocks away when the car started surging, soon after the power died off completely. No matter how hard she pressed on the accelerator, there was nothing, barely a change in RPMs, and the idle was surging a lot. I towed her home, and had to push the car into the driveway, when I tried to drive it, it seemed like there was zero airflow, almost like a plugged air filter or a plugged cat. I'm guessing I killed the ETM, I haven't had a chance to check connections or take the ETM back out yet.
BTW, her car is freaking heavy.

[precopster]

Next time the problem occurs turn ignition off and disconnect the MAF. If the problem immediately goes away the problem is with the MAF.

The Bosch part number you require is 0280218108

[bronson75]

Okay, time for an update.
I finally had time to get to the garage tonight to wrench. I tried and tried to start the car, but it all it did was crank and aaaaaaalmost catch, but never did. I pulled the MAF connector, and nothing changed. I figured it would be a good idea to clean the MAF sensor, so I got a can of CRC MAF cleaner and pulled the sensor. I could see the hot-wire was dirty, a few shots of cleaner shined it right up. Reinstalled the sensor, and still no start. I hooked up my code reader and got a P0102 code (bad MAF sensor). I tried to start it again, it caught, idled for a second, and died. It did this 3 or 4 times.
I decided to look for loose wiring connections and such, and saw that the upper intercooler hose had popped off the intercooler. I was thrilled, I figured I found my problem (I had suspected an airflow problem). Installed the hose, tightened the clamp, and it started, but idled poorly. After a 30 seconds or so, it died, and was VERY hard to restart. When it did, I let it idle while I went inside, when I came back out, it had died again.
I got it running again, and decided to pull the MAF connector, and it died IMMEDIATELY. Reconnected, and it started hard.
At this point, it will start, sometimes hard, sometimes easy, and it will idle, with a slight (50? rpm) fluctuation just below 1000 rpm. I ran another code check, and I'm getting P0236/P0237 (which are not new codes, I've gotten them recently, they relate to boost problems). I can't believe they are the cause of the hard start/dying issue, but I'm not sure.

A few other things I noticed:
The ETS light is currently NOT ON.
-Coming off of idle, when warm, there is a slight stumble before the engine speeds up, it's not a bog-down situation, just a hesitation.
-When I rev the engine, it'll rev to 4200 rpm and stop, it won't go any farther, no matter the throttle position.
-My temperature gauge fluctuates A LOT, it'll read anywhere from cold to middle of the dial. I can actually watch it swing, lately it's been tending towards the cool/cold end of the gauge. I'm guessing the sender is failing, but I'm wondering of the ECU takes this signal to be the actual engine temperature (in most cars this isn't the case, there's a separate coolant temp sender)? I wonder because if that's the case, and the ECU thinks the engine is cold, but actually warm, it makes sense I'd be getting wonky running issues.
I'm almost at my wits end. I plan on sending the ETM in for a rebuild, but I'm trying to narrow down other potential issues first.

[mikealder]

I'm wondering of the ECU takes this signal to be the actual engine temperature (in most cars this isn't the case, there's a separate coolant temp sender)? I wonder because if that's the case, and the ECU thinks the engine is cold, but actually warm, it makes sense I'd be getting wonky running issues.

Indeed the ECU uses the engine temp signal to work out the air/ fuel ratio, if your temp sensor or temp sensor wiring has broken down it could effect the engine behaviour, there is only one coolant temp sensor it is near the thermostat, this feeds the temp signal to the ECU which in turn passes this information to the temp gauge and makes the coolant temp available via the OBD-II diagnostic port. In addition the ECU uses the engine temp signal to work out the speed required from the radiator fan, off/ Lo or High, Lo will kick in around 104 Deg C, for high speed the coolant needs to be nearer 115 Deg C - Mike

[precopster]

+1 Replace the ECT. It controls both the temp guage and mixture. The way these cars diagnose the ETM is quite accurate. If you have no ETM codes the ETM is fine. The other variable for ETS light activation is a wonky pedal position sensor part number 9441116.

[bronson75]

Yep, no ETS light, and no ETS codes read.
Thanks for the info on the temp sender, I'll get a new one swapped in ASAP, I'll do the thermostat at the same time. I find it interesting that one sender feeds both the ECU and temp gauge, but I suppose it makes sense. I come from a world of early water-cooled VWs, WHOLE different ballgame.
I went out this morning before work and started it up, it started right away and settled into a fairly smooth idle. It had sat all night in the garage and was fairly cold (30s).

[MilehighV70XC]

How old it the coolant temp sensor? If the signal is fluctuating it could be sending the wrong signal to the ECU and the ECU is not providing the right amount of fuel.

I had a code 238 similar to your code 236, which is the boost sensor. Some times the car would not start, other time is would drive fine then all the sudden die and would take a while to start again.

I would would start with the coolant temp sensor

[bronson75]

How old it the coolant temp sensor? If the signal is fluctuating it could be sending the wrong signal to the ECU and the ECU is not providing the right amount of fuel.

I had a code 238 similar to your code 236, which is the boost sensor. Some times the car would not start, other time is would drive fine then all the sudden die and would take a while to start again.

I would would start with the coolant temp sensor

I don't know how old it is, but looking at it (from the outside) it looks pretty grungy and certainly not new. I'm picking up a sensor and thermostat this afternoon, I'll get them in and go from there.
My next step (assuming I still get 236/237) is to diagnose and replace, if necessary, the boost sensors.

[bronson75]

Okay, so this afternoon I replaced the coolant temperature sensor (didn't do the thermostat, I forgot I had replaced it when I did the radiator last year). Upon startup, it started RIGHT up, and promptly died. Tried to start it again,and it cranked but never caught. Turned the key off for a few minutes, it started RIGHT up and settled into a nice, smooth, 900 rpm idle. I ran a code scan and got the good old 236 and 237. After it warmed up (nice and slow, temp gauge read perfect), I shut it down, and....it wouldn't start. Tried again, it fired right up.
I let it cool off while we ate dinner, and took it for a test drive, some city streets and a short 55 mph jaunt. It accelerated well, seemed to run fine. I made several stops to take it to idle, it went right to 900 and stayed there. After I brought it home, I shut it off and did another code check, 236 and 237. Restarted it, and this time the ETS light was on. Checked the codes, and got the usual, no ETM code. I plan on heading back out to the garage in a bit and see if the ETS light is off next time I start it.
I'm thinking my next task is the boost control valve and boost pressure sensor. I did a quick check of the lines going to the boost valve, everything looked good and solid.
Is there a way to diagnose a bad valve or sensor? Or should I just plan on replacing them both? Can they be cleaned?

I'm slowly chipping away at all the niggling little problems, hopefully I'll have it back to reliable and back on the road soon. I'll be really glad if it's not the ETM, which at this point, I'm thinking is the case.

Many thanks for all the help thus far, I wouldn't be this far without everyone who keeps chipping in!