DIC is showing a 28TCS - C1276 code and the car has no get-up at all.

I can put it in 1st, TC off and floor it and it takes of like a KIA! Help!

2003 Vert 30K miles

 

There are a number of things that can cause this OTHER THAN the EBTCM and you should explore those inputs first. The EBTCM is expensive to replace.

- EBTCM Ground (G-104 and G-101)
- 12 VDC inputs to the module. Check the underhood electrical center Mini fuse# 5, ABSTRANS and make sure its getting a FULL 12 VDC.


- Steering Wheel Position Sensor (SWPS) This signal can be examined by reading pin 17 on the EBTCM connector. Read it and see if its a clean linar signal in both directions thru the range of steering wheel rotation. Common problem.

Which brakes are being applied? Front or rear?

BC

 

Thanks for helping out. The car is all stock, no accidents, stock wheels and Goodyear Tires. I've been driving it for a year with no issues.

Last week, it threw a P1415 and I replaced the AIR check valve on the drivers side along with the PCV (PCV was just cause it's cheap and easy and I like to know that stuff is working ok) The P1415 code reset to a history code right away.

That night I took it out and was accelerating pretty hard. At the top of first gear, about 5000RPM the check engine light started flashing and it sounded like the engine was knocking or rattling (don't think it's an exhaust jingle). I backed off and the light went out. It did not set any codes that could be accessed via the DIC.

Anyway I think that is when the lack of power started.

Last night I followed a procedure to begin the reset of the fuel tables. Pulled the #16 and 23 fuses. when I restarted the car I had multiple U1016 (lost communication with PCM, probably from pulling the fuse) and the C1276.

Prior to the fuse pulling event, I had cleared all of the codes via the DIC so these were all new.

The 1276 has to do with the torque management and I read somewhere the if there is an "abuse" situation that the car can throttle back performance in order to save itself? If that's the case how do I throttle it back to normal?

Again thatnks for the reply, please let me know if there are more questions that I can answer.

 

If your getting ANY communications code errors,,,you MUST fix them before you go any further. Without ALL the modules working (NO COMMS means NO WORK) your shooting in dark at the moving targets.

Pop out the door accordion tubes and inspect/clean and repair the connectors, inspect/clean and repair the driver seat connector and see if that solves the NO COMMS issues.

If it doesn't, you need to check to see if your having a 12 VDC ignition switch (12 VDC "hot in on and start" ) issue.

If your seeing your check engine light flash during the issue,,,,that indicates a MISFIRE PROBLEM. That can feel like the engine is falling out! Been there!

BC

 

I think the U1016's are due to pulling the 16 and 23 fuses with the ingnition key turned to on. I was following a procedure from another forum.

I will be tracking down the misfire issue. Can you recommend the most common cause. I checked the plug wires for connection and they all looked good.

 

Clear ALL the DTCs and the very next time that the problem happens, read the codes IMMEDIATELY (don't shut down the engine) and post what you find. Some DTCs clear when you shut the car down.

BC

 

Great advice!! I put some new plugs in it tonight and took it out for a drive. I ran it pretty hard to try and get the flashing light. It flashed and set a P0300 code for the PCM. I understand that to be a misfire code. How do I find out which cylider is misfiring?

I was thinking about getting an OBDCii cable and ScanTool so I can run it while I am driving and catch some better data, What do you think?

 

I got an ACTRON CP9180. It is OBDII and CAN Buss compliant. It also has a data log and scan mode. It also checks O2 sensors. It was $140 on the internet.

BC

 

I'm not sure where the particular ground wires are located. I did put a DMM on the ground block on the framerails in the front of the engine compartment and they all looked good. How do I find G106? I read another post from today where that was the problem (http://forums.corvetteforum.com/c5-t...9-misfire.html) . I'd like to check that wire but want to be sure I have the right one.

 

That thread has nothing to do with G106...it's was G107, and that was a unique circumstance....because ALL cylinders were misfiring. If you read the electrical sticky, Bill has detailed where all the grounds are...along with common corrosion problems.

 

Thanks for the mild correction there...

BC,

I think I'll go and clean the grounds in the engine compartment first and see where that takes me. I was able to consistently reproduce the problem today. Under normal driving I am code free. however when I accellerate hard, any gear, the light flashes and throws a P0300. Sometimes it stays until I park the car and sometimes it clears while I am driving. It will sometimes change to an H code and other times clear to the No Code status. No other codes at all.

Anyway, I'll go from the simple to the expensive. What do you think the chances are of it being a ground issue? Should I be concerned with the grounds in the rest of the car (besides under the hood), at least in relation to this problem?

I might end up checking them all eventually.

 

I think it would help if you could get hooked up with a Tech II or data logging software to isolate the cylinder.

 

If your experiencing a MISFIRE condition on one or more cylinders, the PCM detects this thru the crankshaft position indicator.

The reason for a misfire are:

- loss of spark
- Loss of compression
- Loss of fuel

The very first thing to do is positively figure out which cylinder/s are misfiring. Then you can do specific troubleshooting. Your engine seems to run fine under low load conditions. Under heavy loads it misses. That would point to wards a secondary ignition issue (read poor high voltage spark)

Things that effect that are:

-Condition of the spark plug
- Plug Gap
- Plug Wires (condition, fit, & integrity)
- Primary ignition voltages and grounds

If the voltages and grounds for the coils are incorrect, the spark output will not be correct, consistent or dependable.

You have a lot to sort out. I recommend figuring out what specific cylinders are causing trouble.

BC

 

See that pin in the middle, would lose comms while driving to the door module. This was my passenger door. When this occurred the guages would freak out and all sorts of weird stuff.



Released the pin and coaxed it back to normal like..

and all was well, been about 2 years now.

 

Well I guess the good news is that I have some battle scars from the first few steps.

-Plugs are new Bosch Platinum II that were installed after the problem started, installed w anti-sieze. Old plugs really didn't look too bad. electrode ceramic looked tan to brown, pick-ups were pretty dark but had a clear and clean spot where the spark jumps. One plug had some visible carbon around the electrode area, but not too bad

-Plug gap is a wierd one on thoses bosch plugs, not sure they can be gapped with those two contacts to the side of the electrode.

-Plug wires looked to be in great shape, tight (thus the battle scars) and very clean inside the top end, reinstalled with dielectric grease on both sides with good solid clicks

Now for the next question...I am guessing the voltage checks have to be done thru the ODBC plug with one of the various diag tools? If there is another way can you point me to it? and what should I expect to see for voltages?

 

NO! All you need to do is pull the plug on the coil and use a digital volt meter.

 

Bill,

Sorry of the constant parade of questions on this one. I'm an electrical rookie on this car. Am I checking the voltage at the small plug on the side of the module or voltage from the module to the spark plug wire? Also, I have searched for the best way to locate G107, can you jam your hand back that far or do you need to disassemble something to get to it. The engine takes so long to cool here in Texas that I can't get back there until the morning and then I'm off to work. I'll check G107 on Saturday.

 

If your driving the car,,,,I doubt G-107 is giving you issues. Un-plug one of the coil connector plugs on each side. With a Volt / ohm meter, you can check for power, ground.

Maybe someone can post up a schematic. With you admitted lack of electrical skills, it might be better if you find a knowledgeable friend to lend a hand. You still have not posted up which cylinders are misfiring. you need to know that before you can start deep troubleshooting.

BC

 

Bill,

I am still not sure which is misfiring. The DIC doesn't specify the cylinder, just P0300. I am waiting for my ODBC gear to arrive so I can get some better diags while driving. It has never thrown any misfire code but P0300. I read that there is a P0301-308 but I don't get any of those on the DIC.

Thanks for your patience and I will enlist some help this weekend.

Just noticed on my way to work that the DIC was showing a current P1415. This was the first code it threw a few weeks ago. I replaced the check valve next to the drivers side valve cover already. Any chance these two are related?

 

Bill i am having the same problem as you did and this guy..i thought it may have ben the maf i change it and at the same time i put new plugs after all that the problem is still there...under load i can feel the engine misfire and the car starts to shake a bit...throws the flashing engine lite and P0300 code Engine misfire detected..checked all the cylinders number #4 cylinder seems to be the colprit the plug on the 4 is very clean like new unlike the rest were the have a normal tan grayish look to them ...spark is good and the wire is good...i get good spark all the way to the plug...i guess i need to see if the spark goes to the other end of the plug...any sugestions why it would misfire???