I got a CEL today and my codes are P0191, P0514 and P1740. I have had the P0191 and P0514 before and they were benign (in fact, I think there's a TSB out there for this). In about a week the CEL went off by itself. But, I've never had the P1740 before - something about an overdrive solenoid. I have a short commute, so I've been driving my truck with the OD turned off (T/H). So, it never even tried to go into OD this morning. Anyway, I had the trans serviced about 2500 miles ago and it shifts just fine.

It threw the codes this morning (pretty cold for SoCal ~40). My batteries are original and are likely due to be replaced (7+ years). I'm hoping that some electrical glitch due to failing batteries, grid heater and cold starting caused the codes.

Back to the original question: will the P1740 clear itself or do I have to get a reader and reset it?

 

P1740 indicates a malfunctioning torque convertor or TCC solenoid problem. You should have the TCC test done and the 3-4 shift test done.

 

Are those tests that the dealer would do? I don't notice any change in shifting since I threw the code. TC lockup and shifting into OD work normally. I can't tell any difference. But, if there are tests that can be done to see if something is failing, I'm definitely interested.

 

engine dtcs present
transmission dtcs present
transmission temperature too cold
oil pan contains excessive debris
3-4 shift solenoid
shaft or seal damage
tcc solenoid
torque converter

 

You can clear/reset the codes in the same manner you read them by turning the key off on the 3rd cycle..(vs leaving it on for the codes) If the code re-appears then have it checked out.

 

Well, the CEL went off by itself. The codes are still in there (when I read them). I will try the method above to clear them. Because the trans seems to work perfectly, I will clear the codes and see if it recurs. If so, I will definitely get it checked out.

 

I tried this and they don't clear. Am I doing something wrong? On/Off/On/Off/On/Off. Wait a few seconds, then check ... codes still there.

 

They key trick doesn't clear them, it only lets you know if any codes are present.

If there aren't any, all you'll get is ------

If there are codes, it'll be P-----, C-----, or U----- then it'll display --DONE--

You'll have to write them down pretty fast, otherwise your gonna have to start the whole thing over.

 

That's what I thought. But, the post above suggests that you can clear them too. I guess I need to get my hands on a Smarty Jr.

 

The key trick has cleared them for me. If the fault was still present the code son reappeared.