GETTING A CODE 34 LTPWS

[Route 66]

Some time back I took my wheels with tires mounted to a tire shop to have new tires installed. They broke one of the sensors on one of the back wheels. I called a chev dealer an had a new one for that wheel delivered. they installed it. I took my wheels home an installed them back on my car. Since then when I drive slow [ under 30 MPH] for about 1/2 to 3/4 of a mile a service LTPWS comes up on the readout. then when I get to the highway an raise my speed to somewhere above 30 MPH the LTPWS light will go out like it should an leaves a code 34. I bought this car new an have been driving it the same way since I bought it. This never happened tell I replaced that sensor. So I bought another new sensor an replaced that one, GUESS WHAT doing the same thing. The code im getting is a 34 which is a left rear tire. That is one of my problems the other is I can't get the ECM to clear the 34 falt code. I have tried by removing the battery ground cable and waiting 10 min. that didn't work, I've tried by removing the fuse the repair manul said would clear it an that did not remove the falt.
I can't get the engine secondary to work tell I can clear this falt code. I'm not able to get my 405 hp! Has any one had this problem if so I would greatly appreciate your help with this. Thank You ..E

[GOLDCYLON]

When the installer installed the new bands did they install them 180 degrees from the vlave stem? You will need to use a scanner/code reader or a paperclip on the ALDL port to clear the codes.

Look at post #4 for some clearing the codes ideas

http://www.zr1.net/forum/showthread....clearing+codes

[Route 66]

Originally Posted by GOLDCYLON

When the installer installed the new bands did they install them 180 degrees from the vlave stem? You will need to use a scanner/code reader or a paperclip on the ALDL port to clear the codes.

Look at post #4 for some clearing the codes ideas

http://www.zr1.net/forum/showthread....clearing+codes

Thanks GOLDCYLON I used a code reader and tried to clear the falt code useing it as instructed but nothing has worked. That is when I pulled the fuse listed in the instructions that the repair manul said to remove. Yes I made sure they were installed 180 degrees out. I don't understand why I can't clear the falt code.

[GOLDCYLON]

Originally Posted by Route 66

Thanks GOLDCYLON I used a code reader and tried to clear the falt code useing it as instructed but nothing has worked. That is when I pulled the fuse listed in the instructions that the repair manul said to remove. Yes I made sure they were installed 180 degrees out. I don't understand why I can't clear the falt code.

Initally I would have said that you had a lazy sensor a problem in colder weather. However since you have replaced it twice (since breaking the original at the tire shop) with new units something wierd indeed is going on that I have not seen before.

Have you tried the simple paperclip method. Some scanners unless they are a GM Tech-1 cant spirit the codes out of the system where as a simple grounding with a paperclip can. GC

[Route 66]

Originally Posted by GOLDCYLON

Initally I would have said that you had a lazy sensor a problem in colder weather. However since you have replaced it twice (since breaking the original at the tire shop) with new units something wierd indeed is going on that I have not seen before.

Have you tried the simple paperclip method. Some scanners unless they are a GM Tech-1 cant spirit the codes out of the system where as a simple grounding with a paperclip can. GC

My main problem is I can't clear the falt. I would think that it could be cleared by removing the neg battery cable but it will not. It's got me up a tree. Thanks for your help. Anybody else have this problem?....E

[tomtom72]

Hi E, the situation with the LTPWS is separate from the issue with your secondaries being locked out.

The check out the LTPWS I suggest going over to the NetReg site and click the "Maintenance" tab and then click the "How To" tab and it's separated by group headings.

The DTC 34 is a MAP code...at least it is on a 90 ZR-1, so I'm not sure if the DTC's have differing definitions for the 405 cars vs the 375 cars? I do know this: secondary lock out on a 90 is only if the DTC is an engine management system/component issue. I would say to run down the DTC number in the FSM.

Again, the only thing I do not know for sure is if the DTC definitions are the same for the 405 cars as the 375 cars. I may be barking up the wrong tree here ( what else is new! ) but if I'm not then your DTC could be a MAP issue.

In the 90 FSM: DTC34 = signal voltage low/high vacuum on MAP. Possible causes: hose is soft & sucks shut under heavy throttle. Oil flooding the hose or sensor. MAP sensor failure. See Pg A-54 in section 6E


Tom

[John Boothby]

The owner's manual addresses the intermittant "SERVICE LTPWS" light. It can activate under 25mph or if near another car. It is not a faulty sensor. At least that is what my 90 OM states.

[Route 66]

Originally Posted by John Boothby

The owner's manual addresses the intermittant "SERVICE LTPWS" light. It can activate under 25mph or if near another car. It is not a faulty sensor. At least that is what my 90 OM states.

Thanks John...I read that. One of the things Im having trouble with is I can't clear that 34 code from the ECM.
The car is setting in my shop not going anywhere. I try an clear the falt code but it will not go away. I go through the steps to remove it but it is still there.

[John Boothby]

I understand that you do have a service manual? My SM for my 90 has on page/section 8D-36 CCM code 34 as a "Data Clock Circuit" open ciruit or shorted to ground. Could your problem be something other than a LTPWS or Secondary issue? Just a suggestion.

[tomtom72]

Hi E, I figured I might be barking up the wrong tree. Sorry. I have a 90 along with it's FSM. I will have to admit that the early LTPWS diagnostics do not have any listed DTC's for the system. That maybe unique to the early cars. I know the system changed along the production run somewhere because GM separates early & late tire warning systems with different parts. I don't know which model year...sorry about that too. Boy, I'm just one sorry a$$ individual today!

Also, I don't have a code reader so I'm not up on their use. I use an antique snap-on MT2500 scanner or Gordon's jumper kit. That said, I am fairly certain that what I said about "secondary lock out" during a stored engine management DTC applies to all the LT5's...fairly sure.

Try some suction on the MAP nipple to see if ya get some oil out. Check the hose for softness and leakage, as the hose is hard plastic and the ends are rubber. A fwiw about the hose: do not use regular vacuum hose as the LT5 will suck it shut and set a 34 ( for the 90's it's a 34 ) because the MAP gets no vacuum to measure. Maybe you can flush out the oil with some WD40 and then let it drip dry. The MAPs are a bit pricey I think.

I apologize that I am not much help on this one.


Tom