'98 Grand Am ETS Off

martino

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#1
HELP! I've got a 4-cyl 98 Grand Am with the 'ETS Off' light and the 'Engine check' light on. It appears there are a ton of reasons that could make the 'ETS Off' light come on but nothing on quick tests to isolate the source. I have no idea if the problem starts at the engine, wheels, sensors, vacuum lines, etc. AutoZone found only Code 0751, 'ETS Solenoid stuck off'. Can anyone tell me where the solenoid located so I can at least start checking it and wiring to/from it to some source? I MUST get an emissions test asap but will automatically fail if the 'Engine check' light is on....and it is.
Thanks.
 

kev2

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#2
Well .......its not an easy answer I have, First where did you get the code description ETS solenoid stuck OFF?

the code P0751 is a transmission code for a shift solenoid .... Is your transmisson shifting ALL gears?

As for the ETS much of the sensors piggyback on the ABS system AND modules (computers) that cannot be read by autozone.

But the tramsmission code p0751 would afftect the ETS ...... AND drivability issues you should notice.... maybe no 1st gear ?

SUGGESTION.....you will need to have vehicle diagnoised using a scanner capable of reading all modules ....ie ETS, ABS, and transmission sensors, explain your code description...ETS off?
 

martino

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#3
Hey Kev2:
When AutoZone read me the code 0751 because I asked why my ETS light was on, I assumed they were related. Went back to AutoZone today and got more details. The P0751 is for the shift solenoid valve failure. They also found P0507 for the Idle Air Control (IAC) saying engine idle speed is not in it's expected range.

The tranny seems to be fine. There is no detectable slip or hesitation. I paid more attention to the engine running at idle and can feel a very slightly rough idle at around 1500 RPM. When I run up the RPMs in neutral it's smooth until I hit 4000, where it seems like it slips or hesitates. The AZone printout lists some probable causes for the two codes that I can start working on, like replacing the solenoid valve for $30, cleaning the IAC unit, check wiring, clean throttle body. I'd appreciate any more help you can give.
 

kev2

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#4
hopefully vehicle is STOCK no mod's add on's or AFTERMARKET parts??
Be advised codes do NOT mean change parts....

Cleaning thhe IAC & Throtle body routine maintances.... a good start...also looking for vacuum leaks
what is engine idle RPM?

4000rpm take it easy... do you often operate @4k? that sounds more llike fuel press/injector than an IDLE issue...

changing the shift solenoid....without diagnostics or a scan? not a recomendation ...you do know the solenoid is internal to transmission??

The ETC can default (set code) for a transmission problem.... you do NOT know why the ETS light is on without a diagnostic scan.... looking for ALL codes.

taking a swag if vehicle is STOCK ...clear codes, perform a drive cycle and repost .....if codes reappera then a through diagnostic check needed,
 

martino

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#5
The car is totally stock. Didn't mention it but it's been well cared for all of its 120K miles.

I only revved the engine to 3-4K a couple times to check for misfires, etc. Seemed fine.

My trans shows no sign of slipping or poor shifting. The new shift solenoid valve I saw mounts externally with an O-ring seal and electrical connector. Thought I would try it first. But I will take to my local trans shop tomorrow for a scan and let you know what I find out.
 

kev2

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#6
I am NOT a trans the expert ....

the code is a likely source of ETS light... If they see no codes have them turn off cel ....and we will see what happens....
 

Gus

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#7
Anytime a PCM code is set, the ETS system is turned off, so that's why the light comes on.....fix the code and clear it, and the ETS "off" light will be no more...
 

martino

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#8
Kev2 convinced me to try again. I went back and removed the air intake cover and got into the sensor mounted on the throat. I removed the IAC and cleaned it with carb cleaner and air dried it, and put it back in place. Made no difference. Then I noticed the factory vac line to an electronic sensor (don't know what it is and the manual doesn't say). Removed it and found a crack at the bend. Replaced it, started the car and the ETS and Check Engine lights went off in a couple seconds and are still off. I really enjoy working on my own car but computer related problems involve so much I felt lost, and I don't have the tools to do much more than the obvious and simple jobs, and very little computer related tests. I was expecting the worst and planned to take it to a trans shop in the morning.

Anyway, it looks like it's fixed. I can't say thanks enough to all you guys who take the time to answer questions and help. Thanks, thanks, thanks again.
 

Gus

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#9
That was probably the MAP sensor....unfortunately, that is not a cure for P0751.....I would look closely at the harness going into the front of the transmission for any rub throughs in the loom protector....
 

martino

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#10
FYI. Replacing the vacuum hose apparently fixed things. The ETS OFF and Check Engine lights are still off and the codes have cleared, and the car runs fine. Thanks again for the help.
 

Gus

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#11
Well, if the vac line takes care of the code, that's good.....but P0751 won't be fixed by a crack in a vac line....that has to do with the shift solenoid in your tranny, which doesn't use a vac modulator.....it's also possible, they gave you the wrong code, since they gave you a wrong description of the code, "ETS solenoid stuck off", since there is no such thing.....
 

martino

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#12
Just got back from my Illinois emissions test after having put 120 miles on the car since I replaced the vac hose. The car passed everything, no codes, and ran fine. I was told what might have caused the 'problem' was that because the bad vac hose caused the computer to detect incorrect idle rpm, it created a problem with the tranny shifting. At this point all I can say is that it runs fine and I don't have to get another emissions test until June 1, 2010. Mission accomplished.