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Please Help. Ets Off Problem No One Can Fix!!

01-12-2008, 04:36 PM
I have a 99 Cavalier that has given me problems that NO mechanic knows how to fix. The ETS indicator stays on all the time. When driving the car, if the car is cold it runs fine. As soon as it gets warm, it shifts hard. It sounds like it's slamming into another gear (automatic). A transmission shop said it has something to do with the ETS indicator. NO one knows what this part is. Also I had the trouble code ran on it and it came back as: Intake air temp, signal high. PO113. Intake air temp is reading -40 at all times. This came from a transmission guy. SO, if he thought I needed a new transmission.. he'd of loved to put one in. CAN ANYONE HELP ME?

01-12-2008, 11:54 PM
Go to an auto parts store and purchase an IAT sensor. ( Intake air temp) They are like 10-15 bucks depending on where you go. This is quite common for people who install intakes and don't handle their IAT sensor gently. Its a stubburn thing and does effect the transmission like you've stated.

The ETS is the vehicles tractions control system. When engaged it cuts power to the drivetrain to re-gain traction if it is lost. For example in winter and your on ice, your car will act like its in a limp mode. When the light is on, its disengaged.

01-13-2008, 07:54 AM
Thanks so much for that. Now, this sensor being bad would effect the car slamming into gears such as second, third and so forth when you drive? I'll definately try this. Any other suggestions?

01-13-2008, 01:31 PM
yes, for some stupid reason, i have heard from some several other ppl that the transmission slamming into gears was a side effect.

01-13-2008, 01:51 PM
THANK YOU SO MUCH! I replaced the part, and drove it down the road.. even let it sit for a while.. NO SLAMMING!! :) NOW.. whether that will fix it forever.. I hope!!

Thank you SO much for taking the time to help me. I've taken this car to 3 mechanics and NO one knew what was wrong. I've paid SO much money and the part only cost 13.00! CRAZY!! Thanks again for taking the time to respond to me!!

01-13-2008, 03:21 PM
Cody is knowledgable. Welcome to Cavalier AF!

01-23-2008, 10:47 AM
Hey, I have another issue. I replaced the air intake sensor and it worked great. Then I drove it and the ETS off light stayed on.. so I took it to Auto Zone and had the lights checked and reset after installing the sensor. Well, it had another code, PO1621. I had all the lights on the computer reset. The car ran perfect. Then I took a left onto my road, the ETS off light came back on (the check engine light didn't yet) and it started shifting hard again. Can you help me figure out the second part to this problem? Thanks so much

01-25-2008, 12:59 PM
I'm new to this forum, and most of my experience is with older fords. However, it's interesting how some of the stuff is similar. I'm assuming your "ETS" is the engine temp sensor, which you've also referred to as IAT, or intake air temp sensor...Ford calls it an air charge temp sensor or ACT.

Anyway...IF there's an "open" in the sensor circuit, whether it's the sensor itself, or the wiring going to the sensor, the computer defaults to the minus 40 degree setting. In other words, the computer thinks it's real cold outside. This is fine until the engine warms up. That's when weird things start to happen because the computer still thinks it's cold. If you have access to an ohm meter, check the resistance on the sensor (I know it's new, but you could have purchased a faulty sensor). The sensor is probably a "negative coefficient" sensor. This means the lower the temp, the higher the resistance. If you remove it and take it in your house, at 70 degrees it should read about 30,000 ohms. (at 250 degrees it should only read about 1,000 ohms). If there's an open in the wiring, there is infinite resistance and the computer defaults to -40 degrees. If the sensor seems okay, you might want to remove the connector to the computer and read back toward the sensor with your meter to check the wiring. I'm new enough with my Cavalier that I don't know which pin on the connector is the correct one...yet. Someone else will have to help you there. Trust your codes and get them cleared before doing major things, like replacing the tranny.

What is a code PO1621 referenced to?

01-25-2008, 06:13 PM
When I took my car to a tranny place. He put some machine on the car. The ETS light was on. He said the trouble code was for Intake Air Temp signal high PO113, The Intake air temp is reading -40 continually. Another person told me to change out the Intake Air sensor. I did this. I also had the computer reset. When all the lights went off (ETS off light and check engine) the car ran great.. about 5 miles. Then I turned onto my road.. the light came back on and the tranny started shifting hard again. SO, I have NO idea what to do now. I know it's some sensor/computer/hose problem.. just don't know where to start. Can you help? Experience with Fords works just as well with Chevys. The code P1621 was another code that showed up at Auto Zone when they reset the computer. I had two codes. Po113 and P1621. The other guy told me the P0113 was due to air intake sensor.

01-25-2008, 07:58 PM
The P0113 is a fault in the IAT circuit. Since you've already changed the sensor, I don't think a quick replacement of another part will help. I'm afraid you're down to doing resistance checks as mentioned above. If you don't have a meter, or the knowledge to troubleshoot wiring (please, no offence intended), you'll have to take the car to someone who does...a friend, neighbor, co-worker, or to a shop. Since it worked for a little while, I'd definitely re-visit the sensor first. Double-check the plug too.

01-26-2008, 05:42 PM
Thanks for your help. I do have someone who can check this for me. So, what your saying is that maybe since it worked for a short while, maybe the sensor is bad or the plug the sensor goes into may also be bad. If not, then I'll have to check the wiring through out to see if it's bad which sounds very expensive and hard to do. Basically have I narrowed down all the possiblilties? Could it be anything else? Do you have any idea what a trouble code p1621? I just know both codes showed up on his meter before he cleared them out. Thanks again for all your help.

ALSO, I had problems with the grounding. A guy put on a starter and the car hasn't been right since. Could this have anything to do with that. I had ANOTHER mechanic fix the grounding issue.. BUT, I wonder if there is still something wrong?

01-26-2008, 11:35 PM
Ahhh...You may indeed have other issues. Here's a quote from a Wiki site regarding the P1621 on another Cavalier:

A vehicle control module (VCM) or powertrain control modules' (PCM) electronically erasable programmable read only memory (EEPROM) contains data essential to running the engine and transmission. The VCM/PCM stores critical preprogrammed data within the EEPROM, this data remains even if the vehicles' battery is disconnected. At power up the VCM/PCM checks the integrity of this data. If the checksum of the EEPROM does not match a predetermined value, DTC P1621 will set. The DTC will also set if the VCM/PCM is unable to correctly read or finds corrupt data from the EEPROM. GM recommends testing/replacement of the VCM/PCM using required equipment by a qualified technician for this type of VCM/PCM memory performance fault condition.

At first, it sounds like it's saying to replace your computer. But I'd check with a well qualified shop, or dealer, about the possibility of "flashing" your EEPROM first. We're getting into an area well beyond my capability or experience here. But first things first...see if Autozone can reset the computer again and see if it comes back.

01-27-2008, 11:28 PM
hhmmmm..... yea, if your getting that code. I'm not sure. I'm not sure i would trust wiki either. Could bring it to the dealership and pair their diagnostic fee and get their opinion. If its the powertrain control module then and get it from a wrecking yard.

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