Corvette Computer Codes

The ’97-2001 Corvettes Are The Most Complicated, And Yet The Most Accessible To The Consumer

Andy Bolig Dec 1, 2000 0 Comment(s)

Step By Step

Don't you just wish...

The first step in recalling any codes is to turn the key on with the engine off. Clear all present messages such as Change Oil Soon or Hatch/Door Ajar by pressing the Reset button. Then hold the Options button and hit the Fuel button four times. This will put the automobile into the Automatic Sequencing Mode. If at any point you get weak in the knees or have to end the session, you can simply turn off the key and it will shut down the scanning process and return to normal operating mode.

This is how the codes will be introduced. The area affected will show first along with the number of codes that are stored. This photo shows the radio has one code stored.

Immediately following the code count will be the actual code, if any are present. Each code is broken down this way: 80-Radio is the area affected. “U” means that there was a communication problem; 1016 is the actual code description. “H” means that this is a history of a code not currently occurring. A current code would be shown by a “C” in the last position.

Chris suggests that if the codes are history codes, write them down on a sheet of paper and clear the codes by depressing the Reset button. There is no need to be afraid of the presence of codes and, in fact, Chris had a hard time with a reappearing code in a C5, finally determining that his 900-MHz cordless phone was causing it!

If you do see the Service Engine Soon light on, but the car is not running any differently, simply go over the gauges or check the major systems like the oil pressure, water temperature, and battery to make sure they’re registering within acceptable limits. If they register OK, you can simply plan on making an appointment instead of calling a tow truck, but it will let you know if there is a problem.

There are several control modules that will be represented (by using the capitalized letters in their titles) when scanning for codes. They are the Body Control Module, Remote Function Actuator, Powertrain Control Module, Heat Vent Air Conditioning, Traction Control System, Left Door Module, Right Door Module, and Instrument Panel Cluster. The Body Control Module is shown here.

Here's the Traction Control System code. Some differences would be that ’97-’98 Corvettes have a Seating Control Module, which was later integrated into the BCM. Also, ’99 Corvettes have a Sensing Diagnosing Module that contains the inflatable restraint system.

When we first scanned the system for codes, we got a PCM code of P0300. This indicated an engine misfire, which the customer confirmed when he stated that he found a spark-plug wire disconnected. The customer connected up the wire, but the code still appeared in the history until we cleared it.

We had two codes in the PCM.

The second one deals with the Automatic Slip Regulation showing a desired torque signal failure. Once again, the code was a history code and not currently showing. We wrote down the code and reset it to see if it would appear again. When you have more than one code showing for a particular module, always look at the lowest number first and see what effect that may have on the other codes showing. Keep in mind that these systems are very touchy. Having the gas cap loose will give you a code!

Just to give you an idea how integrated these computer systems are, this is a code found in the Right Door Control Module. Even the doors have computer modules in them!

If you care to take code reading to the next level, you can purchase a Tech 2 scanning tool from MAC Tools.

The Tech 2 connects directly up to the link under the dash on the driver side via this connector.

One of the benefits of using the Tech 2 is that you can delve into the available information and check that the system is operating properly. The amount of information available to you at this point is astounding, and this little box will allow you to operate any electrical circuit in the vehicle whether it is turn signals, horn, or even the bells in the dash.

No. Chris isn’t going after some loose change...

He’s removing the panel for us so we could get a picture of one of the fuse boxes and the Body Control Manual. Did you know these were there?

Also strategically hidden is the Powertrain Control Module. Located behind the tire...

...it can be reached through a removable panel in the wheelwell on the passenger side of the car.

Your Corvette uses radio signals for several operations. This is why other radio frequency transmitting devices can throw codes in your C5. The Remote Function Actuator (RFA), which is in the rear driver side of the hatch, receives these radio waves. This is the RFA.

Chris is shows the position of the antenna for the RFA. Also, if you’re in the habit of keeping your key fob in Passive Entry mode and near the car for extended periods of time, the RFA will pick up the radio signal and the car will never really shut down.

The engineers of the current Corvette faced an incredible challenge when they decided to integrate all of their electronic wizardry into one vehicle. With all of that electronic potential, problems are inevitable. At the dawn of the electronics age, no one short of a black-belt technician with thick-rimmed glasses and a pocket protector would dare try to define where the problem was located. As time progressed and more and more people understood the part that electronics play in keeping the Corvette fast and clean, the fear of codes and electronics gradually diminished, and for the owner of C5 Corvettes, the information has actually become easier to access.

We cannot take the space in this story to list all possible codes and their cures—there are 975 pages of codes and cures for just the Powertrain Control Module (PCM) in the C5 Corvette shop manual! But, with the help of Chris Petris of the Corvette Clinic, we’ll take a look at how the owner can use the tools already available to understand these systems, and even become an asset to the technician if one is ever needed.

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