cam sensor trouble on my 99 ta.

**99TAWS6** · 05-22-2009, 09:07 PM

Cam sensor codes since swapped my 408 about 300 miles ago last fall and care went away for winter. Swapped in new cam sensor but problem came back. Car starts harder, tach goes dead and now trying to run 120 low impedence injectors but they don't run with the cam sensor problem. Car switches to batch fire and that don't work on the 120s.The problem is still a bit intermittent. Was dead for quite awhile but for some reason it was ok for 15 minutes the other day and car ran great almost was going to take if for drive but then code cam back again.

So wondering for those of you that had the problem what did you find was cause .Did you replace cam sensor ,did you find cut or burned wire, engine grounds off the back of engine, cam walking in the engine from cam retainers or cam gears coming loose? What did you find to fix the problem. Getting codes 0342 for sure maybe 341 or 340 forget don't think 343.

**0rion** · 05-22-2009, 10:21 PM

never had it happen but you pretty much listed everything I would check. Since you already replaced the sensor I would start looking at the wiring side to see if you can find something going on there like a chaffed wire or ground issue.

**bills98ta** · 05-23-2009, 01:52 AM

Did you try re seating the ecm plugs ? Maybe if you can borrow someones ecm, swap them to see if it runs... I keep a spare, but 98's are different...

**99TAWS6** · 05-24-2009, 12:41 AM

I tried a lot today. Got new battery after reading about couple people who changed battery and fixed problem. I also checked ecu pins, checked continuity to jump plug on my 99 which has jumper plug by egr on intake. Checked voltage to that plug also. Was ok there and on the continuity check.
Started car after all that .instantly got code po342. Tach is dead . Ran tests for signal with hptuners. Got nothing for low to high or high to low.
Tommorrow or next day pulling intake and see what can find after doing that.

**bills98ta** · 05-24-2009, 02:28 AM

If you pull it apart again, when you look in the cam sensor hole, the two half rings on the cam, the one should be centered in the hole, and the other will be towards the rear of engine when turning the motor.
Also, you could add a ground wire to the ecm... I've seen that too... I now floats in a plastic box...

**99TAWS6** · 05-24-2009, 12:26 PM

Todays fun..took off intake didn't see a choice. I checked continuity of the wire from the jumper connector to the cam sensor harness. No problems Wiggled things a bit still no problems. I checked for voltage at the cam sensor connector voltage just like when checked same things to jumper.

So no apparent breaks,power is getting to the female and the female connector looks minty?

So now what..can you see in the sensor hole ok ? I will try to see if reluctor is there or what? Can't see two dud sensors but seems to be only things left are sensor, cam loose or reluctor problem or dud ecu. But the ecu is putting out power so unlikely its just fubared on signal circuit? No other weird things or codes with the ecu either so think its ok.

What an annoying problem. Those ground wires seem tight will double check now that have the intake off the car its easier to check them.These cars are horrible to work on.
I wonder if can crank engine with no fuel or spark intake off and see if get a signal from my hptuners for high and low or does the car have to be running.Would be so much easier to test by just cranking it.

Really hope can figure out this problem starting to think of selling the car.

**bills98ta** · 05-24-2009, 03:50 PM

Should have seen me when I had a damaged tooth on the crank shaft reluctor ring...Wow... I even had a buyer lined up !!! LOL

**99TAWS6** · 05-24-2009, 04:56 PM

How can I look down the hole don't I need a borescope? .not sure can stick my head in there to look. Or were you talking if the engine was out of the car.

I figured out how to check sensor signal with hptuners when you crank over engine don't have to be running.
First checked second sensor it was giving no output which knew as tach was dead. But did have power to the female plug . then put in first sensor and it was giving output on hptuners during cranking.
Then left it for a bit ,came back out and then no output. pulled plug off sensor and checked for voltage as always its there. Plug in sensor again and its showing output.Was going to try wiggling connector tonite and see if can get the signal to ecu to stop and start. Also got spare connector off other guy so could cut and splice it in if need be.

**bills98ta** · 05-24-2009, 05:27 PM

You can use a mirror. cam isn't to deep. Hate to see you get your head stuck in there !

**MYSCZ06** · 05-24-2009, 09:42 PM

wow man what a ordeal I thought for sure the battery was the issue! GL on hunting this down!!

**SteveC** · 05-25-2009, 04:19 AM

The cam has lost its relationship to the crankshaft, and you need to do a "relearn" after the swap. The "Tech II" machines at the dealer, or I have been told that "EFI Live" can also accomplish this.

SteveC

**99TAWS6** · 05-25-2009, 06:02 AM

Originally Posted by SteveC

The cam has lost its relationship to the crankshaft, and you need to do a "relearn" after the swap. The "Tech II" machines at the dealer, or I have been told that "EFI Live" can also accomplish this.

SteveC

Umm you are talking crank relearn .I can do this have hptuners don't need to go to dealer.But can't understand why need to do that. I thought you only need it when you swap ecu ? I did swap motor with difference crank but ecu is the same?? And why then is it intermittent.Sometimes working fine one minute and then no signal from cam sensor the next? Also think you get a code if you need a crank relearn.

**SteveC** · 05-25-2009, 07:58 AM

Originally Posted by 99TAWS6

Umm you are talking crank relearn .I can do this have hptuners don't need to go to dealer.But can't understand why need to do that. I thought you only need it when you swap ecu ? I did swap motor with difference crank but ecu is the same?? And why then is it intermittent.Sometimes working fine one minute and then no signal from cam sensor the next? Also think you get a code if you need a crank relearn.

The code is usually P1336, and it can be set for a variety of reasons, even leaving your key in the on position when disconnecting the battery.

I am not an expert, I would think that a cam swap with a different LSA would be reason enough to do the crank relearn.

SteveC

**99TAWS6** · 05-25-2009, 06:44 PM

Updates.. today buddy came by as 4 hands are better than two.We used the multimeter again and again tried to find something.We got power to the end of the jumper plug. We got power to the end of the sensor harness. We got continuity on the signal wire from sesor to jumper connector. That is pretty much the problem.Always seem to have power to sensor or at least when stick the probe into the connector have power.
Then connected up sensor and it was working putting out signal.I test it just cranking intake manifold still off with my hptuners. But scared to put intake back on till sure its fixed. We wiggled the heck out of the wires at the jumper plug and the sensor connector and cant' get it to cut out .
So ordered a third cam sensor from gm. Third times a charm? Well it seems it has to be sensor, connector to the sensor maybe a loose fit on a pin? we are going to try to tighten up the pins tommorrow. Dont think its ecu if it keeps putting out power or can the ecu get screwed so it can't get signal?? Guess slight chance its cam problem but am getting readings as said.I did buy a new mirror thing so maybe can see in there with this one.Can't afford a borescope.

really hoping to figure out this thing.