Full System Code Reader?

That is because your plugging into the ODB port which is only reading the ECM (engine control module). To read other codes you need to read the BCM.

donn0128 wrote:
That is because your plugging into the ODB port which is only reading the ECM (engine control module). To read other codes you need to read the BCM.

It depends on the vehicle, and I suspect the code reader as to which codes you can read through the OBDII port. On at least one of my vehicles, I can read many non ECM codes through the OBDII port. Scanguage is one such device that in addition to giving mileage etc. readouts will also alert you to many pending codes as well as any "thrown" codes. Scanguage will also let you clear many codes as well.

However, resetting (clearing) the codes is also not always possible through the OBDport. On one of my vehicles, the airbag is one such code that can't be reset through the OBDII port, but needs another device or SW to reset.

However, go to your local auto store, often they can at least read out the code for you.

It really does depend on the specific vehicle. Using my Sprinter chassis as an example, there are "zillions" of codes from every computer in the vehicle that can be accessed via the OBD port, but Mercedes has done an effective job of keeping the chassis-specific codes a secret. There are only a few several thousand $ devices that can read the proprietary codes. You'd probably have better luck on a forum dedicated to the chassis type, rather than an RV forum.

To the best of my knowledge Chevy Express vans only seem to be popular with the trades groups these days and van forums with any decent information are virtually non-existent. I'll poke around the Chevy pickup sites though since the equipment should be similar.

I use an Edge Insight CTS - Displays and clears Diagnostic Trouble Codes.

Norskeman wrote:
I use an Edge Insight CTS - Displays and clears Diagnostic Trouble Codes.

How about the air bags?

Wayne Dohnal wrote:
It really does depend on the specific vehicle. Using my Sprinter chassis as an example, there are "zillions" of codes from every computer in the vehicle that can be accessed via the OBD port, but Mercedes has done an effective job of keeping the chassis-specific codes a secret. There are only a few several thousand $ devices that can read the proprietary codes. You'd probably have better luck on a forum dedicated to the chassis type, rather than an RV forum.

X2

Most aftermarket OBD readers have very limited amount of codes they are able to "read". Most of those codes which CAN be read will be for the ENGINE ONLY.

OBDII ports do have ALL codes available but they do not typically release what all the codes mean.

Reading any other codes including transmission and body codes WILL require a very, very expensive reader from the manufacturer of the vehicle.

Your best bet is to take to your vehicle manufacturers dealer, pay the ransom money to have them hook it up to your vehicle ($100-$200?)..

THE DEALER is the ONLY reliable way of getting the body codes read CORRECTLY.

My two cents

The vast majority of DTC codes can be accessed via the OBDII connector.
There are very very few exceptions for a standard vehicle. The PCM ECM TCM BCM ETC controllers communicate on the very same data bus that the OBDII port interfaces with.

All vehicle manufacturers support a set of emissions related DTC Codes plus they all have their own unique set of codes and programming capabilities. Most manufacturers have tried to keep their unique interfaces secret - the internet has changed all that.

Most commonly available aka low cost dedicated hardware devices aka "code readers" have limited access. This limited access is typically only the engine emissions related codes, some more some less pay your money take your chances.

Suggest you try

A generic ODBII to USB adapter which can be had for less than $10.00 (EBay and Amazon offer dozens of them) many have the capability to transfer 100% of the data available on the OBDII port. A PC based application is then used with these simple data transfer devices. Google OBDII data interface applications, there are hundreds of then some free some with a cost. There are very few limits to the access and control including specific manufacturer codes. Used them to flash program the ECM / TCM / PCM controllers on several vehicles. It's not rocket science anymore any good programmer can create a nice application.

My old hardware based Chrysler "DRBIII" has been outdated by the new PC based applications. Even my Yamaha Speed Density EFI 4s outboard engines can be programmed with many available applications.

Gdetrailer wrote:

Wayne Dohnal wrote:
It really does depend on the specific vehicle. Using my Sprinter chassis as an example, there are "zillions" of codes from every computer in the vehicle that can be accessed via the OBD port, but Mercedes has done an effective job of keeping the chassis-specific codes a secret. There are only a few several thousand $ devices that can read the proprietary codes. You'd probably have better luck on a forum dedicated to the chassis type, rather than an RV forum.

X2

Most aftermarket OBD readers have very limited amount of codes they are able to "read". Most of those codes which CAN be read will be for the ENGINE ONLY.

OBDII ports do have ALL codes available but they do not typically release what all the codes mean.

Reading any other codes including transmission and body codes WILL require a very, very expensive reader from the manufacturer of the vehicle.

Your best bet is to take to your vehicle manufacturers dealer, pay the ransom money to have them hook it up to your vehicle ($100-$200?)..

THE DEALER is the ONLY reliable way of getting the body codes read CORRECTLY.

while I do agree than many "generic" code readers limit the readout to ECM stuff, reading other stuff may or may not be difficult. I've queried many non ecm related codes on my silverado, including many transmission and BCM codes as well, Things like fuel level and any transmission status info as well. and on my mercedes I can get virtually all the codes through the obdII port with simple available SW. That includes things like checking the headrest motors, door lock functions, seat position, seat heater operation, all the AC codes including reading AC pressure.

And alldata often has a very comprehensive and extensive list of codes, not just ECM but body, transmission, etc. along with the recomended diagnostic tree if you need to decipher codes.

However, resetting safety related codes, such as air bag can be very very difficult to do. As you might expect, from a liability standpoint the mfg don't want things like that to be reset without verifying that whatever cause the code to be set is fixed and there are no related issues.

For example on my mercedes, I can easily reset virtually all the codes, except a few "safety" ones, like the airbag. that takes a unique tool to reset.

ktmrfs wrote:

Gdetrailer wrote:

Wayne Dohnal wrote:
It really does depend on the specific vehicle. Using my Sprinter chassis as an example, there are "zillions" of codes from every computer in the vehicle that can be accessed via the OBD port, but Mercedes has done an effective job of keeping the chassis-specific codes a secret. There are only a few several thousand $ devices that can read the proprietary codes. You'd probably have better luck on a forum dedicated to the chassis type, rather than an RV forum.

X2

Most aftermarket OBD readers have very limited amount of codes they are able to "read". Most of those codes which CAN be read will be for the ENGINE ONLY.

OBDII ports do have ALL codes available but they do not typically release what all the codes mean.

Reading any other codes including transmission and body codes WILL require a very, very expensive reader from the manufacturer of the vehicle.

Your best bet is to take to your vehicle manufacturers dealer, pay the ransom money to have them hook it up to your vehicle ($100-$200?)..

THE DEALER is the ONLY reliable way of getting the body codes read CORRECTLY.

while I do agree than many "generic" code readers limit the readout to ECM stuff, reading other stuff may or may not be difficult. I've queried many non ecm related codes on my silverado, including many transmission and BCM codes as well, Things like fuel level and any transmission status info as well. and on my mercedes I can get virtually all the codes through the obdII port with simple available SW. That includes things like checking the headrest motors, door lock functions, seat position, seat heater operation, all the AC codes including reading AC pressure.

And alldata often has a very comprehensive and extensive list of codes, not just ECM but body, transmission, etc. along with the recomended diagnostic tree if you need to decipher codes.

However, resetting safety related codes, such as air bag can be very very difficult to do. As you might expect, from a liability standpoint the mfg don't want things like that to be reset without verifying that whatever cause the code to be set is fixed and there are no related issues.

For example on my mercedes, I can easily reset virtually all the codes, except a few "safety" ones, like the airbag. that takes a unique tool to reset.

That IS why it is OFTEN BETTER just to go to the dealer in the FIRST PLACE.

Even if you are able to pull and read the codes, not all codes are the same or result in the same repair. ONLY the manufacturer knows for sure.

As far as resetting codes, there are many that simply can not be reset without the OEM "tools" and it varies from manufacturer to manufacturer and even then from day to day of manufacture.

Some codes do not need reset, just need a certain amount of "cycles" once the bad part is replaced or the trouble has corrected its self (many emission related codes will turn the CEL off after several successful drive cycles once the sensor is back in operating parameters).

The OP has a Airbag fault, this can caused by errors with the airbags, crash sensors, computer, faulty USED replacement bags (yep, folks DO resell BAD used airbags which had been fired and repacked) or even a bad (or wrong) airbag light on the dash.

With the complexity of todays vehicle airbag systems (my newest vehicle has not only front airbags but side bags in the seats and airbag side curtains in the roof, all told six airbags that would be a lot of money and time to find a bad one) sometimes it is cheaper, quicker just to pay the dough at the dealer...