Several codes last night

[Don-T]

I have had a TST box on my truck for a couple of weeks now and no trouble. Last night the engine light came on and I checked the codes they are:



P0336 Crank Position Sensor

P0480 Cooling Fan Control Circuit

P0646 A/C Clutch Relay



I was accelerating to get on the freeway when they came up. EGT was just under 1200 and boost was 35. I have the box set at 5/5. The truck ran fine the whole time. The only other issue I have is that if I hold WOT too long I run out of fuel. I think I will buy a FASS system to fix that.



Could the codes have been caused by the TST box or is it something else?



The engine light is out now but the codes are still stored in the computer. Can I buy something to clear them so I will know if they happen again?

 

[rbattelle]

The codes will remain stored until you get 40 consecutive warmup cycles (coolant temp 160 or more and a rise of at least 40 degrees) without the codes re-appearing. Don't worry, if they do reappear the check engine light will come on again.



In my opinion, the TST box caused this condition.

 

[Gary - K7GLD]

I can't see ANY way the box would create codes strictly isolated to the CPS and cooling circuits...

 

[rbattelle]

Well, maybe I was a bit hasty. I don't suppose there's any reason the TST box would mess with the A/C clutch relay. On the other hand, those three codes seem to be unrelated otherwise.

 

[Loaded 45]

The P0336 code was probably set by the TST at the time , the other two codes could be there from some other event. My tst will only throw the p0336 code if I really lug the motor -only happened once.



I always carry a OBD II Code reader - there cheap. It will clear any set code or freeze frame event set by the trucks computer.

 

[Gary - K7GLD]

How does a TST link to the CPS?



OR to put it another way, what function or operation of the TST interfaces with the CPS?



Just curious...

 

[ThomasLawrence]

How does a TST link to the CPS?

The TST has 6 in-line connections:



MAP sensor

3 Injector harnesses

Crank sensor

Cam sensor



Output of the factory crank sensor (and cam sensor, too) goes to the TST box. The TST then passes on a slightly tweaked signal to the ECM. This is how it does the timing advance.



Ditto on the MAP connection. The TST reads actual boost from the MAP sensor, but then drops the voltage to an ECM-acceptable level before passing it back to the ECM. This 'boost-fooling' prevents the over-boost codes and the defueling that the ECM would otherwise do upon observing that much boost.



As for the connections to the injectors, I'm assuming this is for the increased pulse width. The ECM probably triggers the injection event based on it's own criteria, but once an injector's opened, the TST continues to supply voltage to the injector after the point in which the ECM drops the voltage. I'm basing this on the fact that TST told me if I ever needed to remove the box, that the injector wiring harness could remain in place. That means that the electrical path from the ECM to the injectors is not interrupted by the TST harness. Therefore, the TST connections to the injector circuits must be in parallel with the factory paths. (And actually, now that I think about it, voltage is probably present all the time - the ECM and TST are probably just switching ground to energize/de-energize the injectors).



-Tom

 

[Gary - K7GLD]

Thanks for the info Tom...

 

[Don-T]

RadRam

That makes a lot of sence. I may have set the others when I was messing with my alarm system and not noticed. What do you have for a code reader to clear codes and where did you get it? Thanks for the help.

 

[robertyoke]

Don-t call tst and let them know.



'cause what may seem simple is not.

I had my new box (program change) from tst, put it on my truck, and noticed that my a/c quit working (po647 code) I thought it was a/c problem but I could not figure it out. After I took box off a/c worked fine. After taking box on and off about 3 times I realized it was the box. After talking to mark,scott, and greg, they told me they only saw that on the pre production box and never again.



So far I have traced the problem partly to the pusher pump and used a relay off the battery instead of the stock circuit and also grounded the pump itself (it's not self grounded). The problem may be gone, but I have thought that before, then it comes back.



I also moved the tst box ground from the fender to the battery and I got codes 336,606,647,341.



now the ground is inside the cab with a switch so the box can be turned off.



btw that makes a nice valet switch! and the boost fooling still works.



I also have a scan tool/code remover that is an Acutron OBD II, and I got it from Advance Auto and it's a handy little tool especially when you have new codes come up every day .

 

[sagebucks]

I found that by fidgeting with the key, just turning it back ever so slightly I can turn off ignition power. In my case this sent 0480 and 0243 codes, two completely unrelated codes, accept they can both be set by a loss of ignition power. The problem was from an overly obese key chain swinging from the ignition.

 

[Gary - K7GLD]

Shucks - I got codes on mine a couple of times by simply turning on the ignition to unlock the steering wheel, then letting the truck roll downhill into the garage - I guess the ECM sensed drivetrain rotation with no engine power, and complained...

 

[jdh63]

Code Help

I've had the TST box on my truck for 2 days now and the engine light just came on. How do I find out what code is tripped?

 

[ThomasLawrence]

How do I find out what code is tripped?

Cycle the ignition key from OFF to ON (not to START) three times - OFF-ON-OFF-ON-OFF-ON. The odometer will display each OBD-II diagnostic code. There's a list of them on this site.



-Tom

 

[Don-T]

I talked to TST yesterday. They said the P0336 Crank Position Sensor is from them. They are working on a fix. They don't think the P0480 Cooling Fan Control Circuit and P0646 A/C Clutch Relay are from them. I found a Actron code reader last night that was able to clear the codes. If they all come back at the same time I will call TST again.

 

[jdh63]

Code Help

Thanks Tom. I got the P-0336 crank sensor code.

 

[TheWolf]

so the TST is still throwing codes? I thought the falsh/reprograming took care of the codes. Any one else still having codes thrown every now and then?



I was getting ready to see about purchasing one soon but would like to wait and see what edge has if the tst is still having code trouble. (actually wanted to check out the tst at T. I. M. this weedend)

 

[hotram03]

Hey Don-T I also have the P0646 AC relay code as well, I think it is from theTST box, anyone notice a stumble every once in awhile when just easing around? Mine will burp(stumble) from time to time I think it is the TST box as to it started after install, put dielectric grease on all conectors but hasn't helped?

 

[Don-T]

I bought a code reader and was able to clear the codes. It now says there are no codes on the scanner but when I cycle the ignition key three times I get a P0480 Cooling Fan Control Circuit code. The engine light has not come back on and everything works fine. I have not noticed any stumble. My truck runs fine.

 

[Not_Agn]

I have noticed a stubble every once in a while. I also have the A/C circuit high code. All of a sudden this code come up. If the box is on the a/c won't work, turn it to 0-0 and the a/c works. Talked to my buddy who is a service manager at dodge, and he said if the computer notices something trouble some the first thing it does is kick the a/c off. Even if it is a trans code, etc. I guess that makes sense, but why all of a sudden does it trip it now. I called tst tonight and the lady on the phone said they had the codes fixed, and now they have just started to resurface. They have the engineers working on it as we speak. My question is if they are gone for a while, why do they resurface? Anyway I asked if they were going to be at T. I. M. she said they would be there but wheather they would be able to reflash the unit she didn't know. Mark was gone already. I am going to call him in the morning. I will post later what he has to say. Lee.