While on cruise control at 68 mph the engine rpms increased and after the ignition was turned off the car slowed to a stop. After restart there was no forward or reverse motion in any gear with the engine running, the car was towed home. There are no codes. Any ideas what broke? I don't plan on repairing this until next spring. The car is at 115,000 miles but an RPM transmission was installed about 30,000 miles ago along with new torque tube parts and a van torque converter.

 

Is the transmission engaging at all? Did the shifter cable snap? Are you leaking fluid? A lot more information is needed.

 

A couple of other questions:

When you have it in drive, does the speedo register speed increase as RPM increases?

Any Oil/ATF under the car?



When you are in PARK/ E Brake OFF, can you roll the car forward or backward?

Any PCM related DTCs??

READING YOUR Engine Diagnostic Codes



The Diagnostic Display Mode is entered with the following procedure:

1) Turn on the ignition but don't start the engine. NOTE! You can read the DTCs with the engine running and or driving down the road but it can distract you. BE careful! Some DTCs clear themselves when you turn the ignition OFF!

2) Press the RESET button to turn off any warning messages. (i.e. door open, trunk open ect)
3) Press and hold OPTIONS
4) While holding OPTIONS, press FUEL four times within a 10-second period.


Initially, on-board diagnostics go into an Automatic Mode which shows diagnostic codes in a pre-set sequence: PCM - TCS - RTD - BCM - IPC - RADIO - HVAC - LDCM - RDCM - SCM - RFA. All codes will be displayed for each. ( i.e. PCM = 4 codes) If none are present in a given module, you will see No More Codes on the display.
There are two kinds of diagnostic codes, Current and History designated with a letter suffix, “C” or “H”. A current C code indicates a malfunction is present and active in the module displaying data. A history code indicates a problem existed sometime in the last 40 or 50 ignition cycles. When not accompanied by a current code of the same number, it's potential evidence of a previous problem, now resolved, that was not removed by clearing the codes.
More likely it's an indication of an intermittent malfunction.
Intermittent codes are the most challenging of the diagnostics. An intermittent code may have happened once, may have happened more than once but is inconsistent or may be happening on a regular basis but not at the time the codes are displayed. History codes can also be caused by a current malfunction in a system that is not operating at the time codes are displayed. An example is the rear window defogger which doesn't operate until the Body Control Module detects engine rpm. For history codes set by a module that does not operate with the key on and engine off, a special diagnostic tool called a Scan Tester is necessary to properly diagnose the malfunction.
Once the system has displayed all modules, it goes into the manual mode which allows selection of each module using combinations of Driver Information Center buttons. Manual mode can also be entered during the automatic sequence by pressing any button except English/Metric (E/M). Once the display shows Manual Diagnostics, select a module by pressing the OPTIONS button to go forward or the TRIP button to go back. Once a module is selected, a code is displayed, and if more than one are present; press GAGES to go forward or FUEL to go back.
To exit the diagnostic mode at any time, press E/M. If you want to erase codes in a given module, press and hold the RESET button To reset the codes once in manual mode, press and hold RESET until it displays NO CODES Press OPTIONS to go to the next module. Repeat the steps until you have reset the codes in all the computer modules.
NOTE!! Only reset the codes IF you want to - it is NOT necessary to do this. Clearing a code does not repair a problem. You are simply erasing the evidence of it in the module's memory. If you clear the code/s, and extinguish the Check Engine Light, your emissions status ready will NOT allow you to pass an emissions test until you have completed the required driving cycles.
Once you have the codes, the next question is: What to do with the information?
First, consult the factory service manual. Any serious C5 Do-It-Yourself owner should invest in the Corvette Service Manual of the appropriate model year. The Service Manual is really a requirement if you want to understand and work on your C5. You can GOOGLE the DTC and also find information on it.




Here is very good site that explains the DTCs:


http://www.corvette-web-central.com/C5DTCcode.html


http://www.obd-codes.com/trouble_cod...d-ii-codes.php



Make sure to include the H or C suffix!!

 

Could it be the driveshaft couplers , that would give u no drive or reverse in a hurry!

 

There are no fluid leaks, the parking gear holds the car as it should and the speedometer doesn't move off zero when the engine is revved. Last week there were no codes but today these came up: 135, 1120, 1516, 1278 and the traction control fault light is on. I suspect the couplers also, at least they're cheap compared to the transmission or differential.

 

Couplers don't just FAIL and don't couple... They shread and make all kinds of noises and vibrations.

You either have a pump failure or differential issue

Jack up the rear end put the transmission in Neutral and see if you can spin one rear wheel and see if the other wheel spins in the same direction.

If you can hold ONE wheel and easily spin the other, the differential is damaged (broken output shaft)

Bill

 

This is in response to 73 Corvette's post about results of a problem, this one was different from the usual slipping A4 transmission. I removed the drivetrain and found that the couplers were fine; the transmission and torque converter were sent back to RPM. The diagnosis was the front pump on the transmission failed (see Bill's comment) and that's why the car wouldn't move on it's own power, when the pump failed it sent debris throughout the transmission. The pump was replaced and the transmission rebuilt, a new performance torque converter replaced the old one; all this fixed the original problem.

 

 

What did RPM have to say about a pump failure after only 30,000 miles? I've heard mixed reviews of their customer service.

 

They said the pump failed, I don't think pumps are changed when a transmission is rebuilt for exchange at the lowest cost stage. Is it possible that the converter failed first and sent junk into the other parts which caused the pump to fail? This converter was the rebuilt GM van style that offered a slightly higher stall than the stock C5. The new performance converter RPM sold me looked a lot stronger than either of the GM converters. Did the extra power of heads and a cam required an aftermarket converter in the first place?

 

The converter shouldn't cause the pump to fail, unless it sends so much debris out that it clogs the filter and starves the pump.

I'm surprised that they don't at a minimum open up the pumps and do an inspection for all rebuilds.