92 Cavalier, 8 DCT codes.

Today I decided to mess around with the new Innova 5610 scanner I got for my birthday. I wanted to see if this new scanner would pull up live data on an OBD 1 car. I have all of the OBD 1 cables and adapters from my older Innova 3140d scanner that will work with the 5610. There was nothing wrong with the car other than it idles kind of rough in gear when warmed up but it's done it for years.

I get back from town and hook the scanner up. It comes up with 8 trouble codes which are: 13- O2 circuit, 14- coolant temp sensor, 21- TPS sensor, 23- MAT sensor, 24- Vehicle speed sensor, 32- EGR, 33- MAP sensor, and 42- EST. These are just basic descriptions because I didn't want to write out the entire description for each code. The car is fully warmed up.

Basically these are 8 out of the 12 codes that can come up on this car according to the factory service manual.

The CEL light is not on even though the scanner says that the MIL is on.

I then hook up my older Autoxray 6000 scanner which does read live data on OBD 1 vehicles and it shows that there are no codes stored in the computer at all. I then hook up my Innova 3140 scanner and it shows the same 8 codes as the 5610 scanner does. I try to erase the codes with the scanner but it won't let me.

Even though the CEL is not on and the car is not running any different than it has been for years, I decide to clean all of the main grounds just in case they weren't getting the best contact. I clean them very good and hook both Innova scanners back up and still get the same 8 codes. I had unhooked the neg side of the battery when cleaning the grounds so the codes should have cleared.

I decided to check a couple of the 5 volt reference signals just to see what I get. I test the TPS and the CTS and both test at 5 volts so I know the ground and power from the ECM is good to those two at least. I figured with all these codes, that the ECM had to be involved. Could the ECM have an issue that would cause the scanners to read that there is a problem but still not turn on the CEL and not change how the car runs? I've hooked the 3140 up in the past and it never gave me all of these codes before.

It got dark so I quit. I'm more curious than concerned but has anyone run into something like this with using different scanners and getting different DCT codes, especially with no CEL light on? The CEL does light up when you first turn the key on so I know it works.

I'm going to call Innova tomorrow and see what they say about it. Maybe some issues in their programming. Also the 5610 does not read live data on an OBD 1 vehicle.

Thanks for any input since I have never run into anything like this before.

Try reading codes manually. Then try intentionally setting one. Punch it in the face and see if it says OW Link to pdf: www.mediafire.com/file/gshgm3whf01n66v/t..._codes_2.2L.pdf/file

Thanks for the link. Years ago this is how I used to retrieve codes on these OBD 1 vehicles before I had a scanner. I actually had a tool or had made one to jump those two terminals. I will have to see If I still have it.

I found my jumper key and the only code that comes up is a code 12 which I think I read somewhere will come up if you jump those two terminals. No other codes came up, just the 12 over and over again.

The fan also came on when I used the jumper and I'm not sure why or if it was supposed to.

I guess I don't have any trouble codes stored and the two scanners are wrong for some reason.

Dunno why fan would turn on. I noticed quite a few of the "codes" were related to voltage high codes and these sensor share common ground. Perhaps it's something to keep in the back of your mind. Could be something. Could be a fluke. Try a visual inspection of that ground wire. Give it a shake lol. MAT = Manifold Air Temperature which was new to me.

Like I wrote in my initial post, I removed and thoroughly cleaned all of the ground wire eyelets as well as the posts that they attach too. There are two main grounding areas, one on the back of the block that has two ground wires going to it and about five wires going to the ground post next to where the starter mounts. I also cleaned the one ground from that post that goes to the frame of the car and cleaned that end as well as cleaning the frame.

I called Innova today to see what they would say. I got some tech that told me that since I wasn't able to erase the codes from the Cavalier with it hooked up, that I needed to hook it up to one of my OBD II vehicles and erase the codes out of the scanner. That didn't make any sense to me but I tried it anyway.

I hook the 5610 scanner to my 1998 Chevy K3500 truck. I look up DTC codes and it gives me one. PO339 which is an intermittent Crankshaft position sensor B circuit. This might be from oil since this sensor looks like it's had oil leak down on it. I'm going to clean it the best I can. This never has set a CEL.

I then look up enhanced OEM codes and it gives me 40 DTC's. I know this can't be right because the CEL is not on and the truck probably wouldn't even run with that many codes coming up. I tried erasing the codes and while it did erase them, the tool immediately re-scanned the computer and all 40 came back up. The P0339 code did not come back up after erasing the codes. I think it

I hook up my old AutoXray 6000 scanner and of course it shows no codes.

I call Innova back up and explained what was going on and this different tech says he has never heard of this happening and that something must be wrong with the scanner so I have to send it in for them to check it out. To be honest, I don't think they are going to find anything. They said something about them doing a hard reset on the tool. I guess we shall see.

I sent the scanner back to Innova today.

I did forget to say that after every DTC on the truck scan, it had the phrase: "Not passed SC" The Innova tech that I talked to said he had never seen those words and did not know what they meant.

Maybe SC means Smog Check? www.gmfullsize.com/threads/check-engine-code-help.325633/ I'm going to say this is definitely buggy scanner software.

I guess that is possible. I'm not sure if a smog check would be applicable to every DTC which I assume is probably all or most of the DTC's that can be read from this truck.

Thanks for that link. That is the same thing I was seeing on my scanner. By the way, Zurick scanners are made by Innova.

I counted the DTC's he has listed and it comes up with 40 as well and they appear to be the same ones that came up on mine. I didn't really understand what he did to fix the issue though.

I may have sent off the scanner for no reason.

It is not uncommon for the ecm to turn on the fan in diagnostis enable mode. I used this feature to check fan operation when diagnsoing an overheat.
If you don't see a check engine light, and flash codes don't yield codes, then your scanner is likely lying to you.
Edit; SC means "since cleared"

Innova finally returned my scanner and of coarse found nothing wrong with it. They did verify that the words "Not passed SC" means that the vehicle has not passed a "Smog Check" yet and that you have to drive the vehicle to clear out those 40 DTC's on my truck.

I assume it's kind of the same on the cavalier's DTC's even though it didn't say those words after the DTC's. This scanner does an Emissions/smog check readiness check on the vehicles to see if the vehicle will pass.

The scanners list out the checks the ecm/pcm needs to do during a start cycle (engine cold started, idle for 2 minutes, then driven till operating temp is reached and catalytic converter is at operating temp and closed loop is achieved) this can take two to three days to do. It is just how those scanners work as they pull both pending test and actual set codes so don't panic thinking you have a boat anchor for a car.

As for the codes you have wait for the car to run the cycle checks and see what comes back.
If tps does come back then check signal wire with dvom to see if the signal drops out (falls to zero volts) while slowly pressing down has pedal with key in run position engine off. If it drops out it is bad if not tps is ok.

Thanks for that additional information. I didn't really think that all of these codes coming up was legit because the check engine light never came on and any of these codes if there was a real problem, would set off the CEL. The other older scanner that I used on the car does not do the emissions readiness checks and did not find any DTC's in the computer.