Expected a P1456, got a whole list

[BrianZ54]

I went to Auto Zone to have CEL code checked. I just tightened my gas cap two days ago and thought that light should have gone out. I fueled up about a week ago and I always ratchet the cap tight but it was down a 1/2 tank and the cap was just floating loose two days ago.

They pulled 3 codes: P1456 as expected plus P1644 and P1791. I guess I have a couple questions on these. How long would those codes remain in the system? I did have some work done on the AC just over a week ago. It might explain the 1644, I'll ask the guy who did the work tomorrow.

The 1791 is more puzzling. VSS, electrical or lock up clutch issue as per the free code printouts. I'm trying to avoid the dealer but is it time to go see them? They always try to sell us something we don't need.

I'm not too certain about clearing them and starting over, either. I certainly can't determine if there are any new issues when the CEL is on constantly. Any advice is greatly appreciated.

Brian

[gilbertguy]

Brian,

Here is some info for you on the 1644 code -
Need P1644 Help


Also, I don't think you really said if your car is still driving with these codes? What are the symptoms it is having? Will it start? IMA working? Give us some more info if you can. It is a little suspicious that you had work done to the car less then a week ago and now are having issues? Check all your electrical connections to make sure everything is secure.

[Hybrid-Battery-Repair]

Originally Posted by BrianZ54

I went to Auto Zone to have CEL code checked. I just tightened my gas cap two days ago and thought that light should have gone out. I fueled up about a week ago and I always ratchet the cap tight but it was down a 1/2 tank and the cap was just floating loose two days ago.

They pulled 3 codes: P1456 as expected plus P1644 and P1791. I guess I have a couple questions on these. How long would those codes remain in the system? I did have some work done on the AC just over a week ago. It might explain the 1644, I'll ask the guy who did the work tomorrow.

The 1791 is more puzzling. VSS, electrical or lock up clutch issue as per the free code printouts. I'm trying to avoid the dealer but is it time to go see them? They always try to sell us something we don't need.

I'm not too certain about clearing them and starting over, either. I certainly can't determine if there are any new issues when the CEL is on constantly. Any advice is greatly appreciated.

Brian

P1644 is a problem with the wiring to the MCM.
P1791 is a problem with the VSS for your CVT.

Send me an email and I'll send you the testing scripts.

[BrianZ54]

Originally Posted by gilbertguy

Brian,


Also, I don't think you really said if your car is still driving with these codes? What are the symptoms it is having? Will it start? IMA working? Give us some more info if you can. It is a little suspicious that you had work done to the car less then a week ago and now are having issues? Check all your electrical connections to make sure everything is secure.

Sorry Gilbert - I'm slow getting back and answering emails. Everything is working perfectly as far as I can tell. Once last summer and another time last week I got a CEL and found the gas cap very loose. Last year the CEL cleared after about a day, this time it stayed for a few days. Except for the clutch on the AC there's been no mechanical issues for the 22 months I've owned it. If not for the gas cap I don't think I'd have discovered the other 2 older codes.

One time about 3 months ago I was accelerating and it bucked a couple times then went back to normal. I watched for the CEL, but nothing came of it. I was guessing something moisture or something in the gas. That's why I was wondering if the system retained history of codes for weeks or months. There's been no chronic or redundant issues, the AC going down in 98 degree weather was just Murphy's Law reminding me it was still in effect. I'm just not experienced with heavily computerized cars.

Thanks,
Brian

[BrianZ54]

We couldn't find anything wrong that resembled the description of either "mystery" code. After a few more days I pulled the hot wire off the 12V battery and gave it a minute to forget all the scary stuff. More than a week later it's still running well without CEL showing up again.

As I had expected the IMA is acting a bit differently. The charge is seldom below 13-15 bars. It must be background charging more instead of getting down below 10 bars and showing 4 bars of charge until it's back up.

Seems like the mileage is slightly better but we've also had a moderate break in the hot weather. Too many variables.

Again, thanks for the replies and advice,
Brian