Hi everyone. My wife's 2006 HHR 2.2 (43k miles) failed it's emission test this morning. The reason given was that the RPM sensor was giving a "not ready" status. The rest of the OBD passed fine. The OBD hasn't been reset and no battery disconnect. Has anyone else had this problem? It also seems the RPM sensor itself isn't available as a replacement part. They told me we should just drive around until the sensor shows a "ready" status, but that seems funny since there has been no OBD reset.....Thanks in advance!

 

First off, to the forum.

Going to make an educated guess here and say that instead of an "RPM sensor" the vehicle may have a diagnostic code set for the Crankshaft Position Sensor, or a missing signal from that sensor causing the testing equipment to generate a failure report.

The CPS determines the position of the crankshaft for ignition timing purposes, and its rotational speed. The part is readily available, here's a link to just one source.......

http://www.partsgeek.com/gbproducts/...FeRj7AodNFIAHw

If the report given to you by the inspection station has the OBD trouble code noted, please post it up in your reply, it makes the difference between an educated guess, and a definite determination of what part actually has failed.

 

Or go to your favorite Auto Parts chain (Autozone,AdvanceAuto,OReilly etc.) and ask them to read your OBDII codes. Most do it for free, be sure to get the actual numbers (Pxxxx)! not the verbal description .

Then come back here with the actual code and/or punch the code into Google.

 

Thanks for the replies! I forgot to mention that the "check engine" light is OFF. And yes, the light DOES work. So the car failed, but there are no trouble codes being thrown. I do have an OBDII reader, but as you'd guess, it's useless without a code!! Which brings me back to my original dilemma....

 

I would try a different e check station. Here in ohio you can go to a state testing center and if Your car has not run all the test they can run a full test and certify your car.

 

It sounds like you are referring to the I/M readiness part of the California emissions test. If that's the case, no code will be present. There are 11 possible monitors on that test but most vehicles only use 8 or 9 of them. "RPM Sensor" is not in one of the monitors, however that I am aware of. Are you sure that's what the 'technician' said? Could he have said VSS (vehicle speed sensor)? That would be within the parmeters of one of the monitors. There many reasons besides clearing codes or disconnecting the battery that could cause this. Even a temporary glitch since the CEL is not on. I would run a drive cycle, as suggested before replacing components or trying a different station.

 

Thanks again for the replies, guys. For what it's worth we are in Massachusetts (which is as about as bad as California). When they add a test in California, it usually happens here the next year. I am looking at the printout from the inspection station. It says that the OBD RPM check failed. Below that it says " This vehicle has failed its emissions test because the OBD system did not provide information about the engine's revolutions per minute (RPM)." We are taking the car on a long road trip next week (600+ miles). I think I'm going to try a retest when we get back. (We have 60 days to drive the car legally). Hopefully all those highway miles will do the trick. Otherwise, I might try replacing the crankshaft position sensor as suggested above. It would make sense that the CPS would cause an RPM fail. Even so, am happy to hear from anyone who might have something else to add....

 

I am curious. If the RPM sensor was not providing information to the OBDII, wouldn't the Tach on the dashboard be showing zip?

Does your OBDII reader have a live data readout, it should show the RPM. My ELM327 and android app combo does, as well as I/M readiness tests.

I am thinking the test station might have bad equipment or a bad tech.

 

I'm with Don here, a bad CPS would do more than just cause the loss of an rpm value during an emissions test, your HHR would be running poorly with a CEL illuminated.

Not being familliar with Mass e-check laws, does the 60 day test failure waiver allow you to take the vehicle to an alternate testing location? If it does, you can try an alternate testing station to eliminate the faulty equipment/poorly trained technician variable.

 

If Mass. is anything like Cali., the equipment is inspected and certified on a regular basis and basically all the technicians do is plug the vehicle in an read the results. (That's why I put the term technician in parentheses earlier). I have a freind who has a shop that does emissions testing. He regularly tells me what a P.I.T.A. the state is about the emissions program. If it's like here, it really wouldn't matter where you had the test done.