1984 Coupe RPO code number

[Bruce R.]

My 1984 Coupe has a RPO code YA7 which I cannot decifer - can anybody tell me what this code means please?

[Steven B.]

Re: 1984 Coupe RPO code number

I could not find anything in the Black Book. I have a 1984 ordering sheet somewhere around here and will look for it. I believe the Y prefixes were for emissions.

[Joe L.]

Re: 1984 Coupe RPO code number

Bruce and Steve----


Y-prefix RPO codes are not limited to emissions control items. Many are "decorative trim" groups. However, in this case, YA7 is an emissions-related item. YA7 is NOT an orderable item, though. It is a code for a California emissions assembly line TEST. Basically, it is a COMPONENT of the YF5 California emissions requirements. I'll bet the car was originally delivered to California (or, delivered to a dealer in another state but destined for a California customer).

[Steven B.]

Re: 1984 Coupe RPO code number

Bruce and Steve----


Y-prefix RPO codes are not limited to emissions control items. Many are "decorative trim" groups. However, in this case, YA7 is an emissions-related item. YA7 is NOT an orderable item, though. It is a code for a California emissions assembly line TEST. Basically, it is a COMPONENT of the YF5 California emissions requirements. I'll bet the car was originally delivered to California (or, delivered to a dealer in another state but destined for a California customer).

Thanks Joe. I had a brain lapse---I have two cars with YJ8's that certainly have nothing to do with emissions. YA7 being the TEST "component" of YF5---does that mean the system was tested, passed and accepted by CARB? How many "components" make up the emissions codes?

'Learn something everyday.

Thanks!

Steve

[Joe L.]

Re: 1984 Coupe RPO code number

Thanks Joe. I had a brain lapse---I have two cars with YJ8's that certainly have nothing to do with emissions. YA7 being the TEST "component" of YF5---does that mean the system was tested, passed and accepted by CARB? How many "components" make up the emissions codes?

'Learn something everyday.

Thanks!

Steve

Steve-----

As far as I know, the test code means that the car was tested to California emissions standards. The certification code indicates, in essence, it "passed the test" and is certified to meet California emissions standards. I don't think there is any process for "acceptance" by CARB, per se, for any individual car.

I don't know how many codes might be involved for the emissions certification. I think this varied by model year and the specific federal and California standards that existed for any particular model year.

[Steven B.]

Re: 1984 Coupe RPO code number

Thanks Joe! I appreciate the background!

Steve

[Joe L.]

Re: 1984 Coupe RPO code number

The way I understand the "California Emissions YF5" thing is that all cars destined for California are tested on the assembly line to be in compliance. As far as I know, most all production cars comply with California emissions requirements, in that they have the required equipment and calibrations, even if they are not destined for California. This has been true for about the past ten years or so.

The difference is that California requires every new car sold here to be certified by the manufacturer to be in said compliance. The only way to do that is to test every car as part of the production process. Costs $100.

Dave-----


California does require that each car be certified to meet California emissions standards and this is what results in the requirement for the assembly line test. With the "spread" of California emissions requirements to other states in recent years, I don't know if assembly line testing and certification is required for those states, or not.

However, while assembly line testing may or may not be required only for California-delivered cars, the emissions control systems of cars delivered to the other 49 states are not necessarily the same as those delivered to California. The last year that I know of that there was an actual difference in the engines was 1984 (the year of the car which is the subject of this thread). However, after that time there were often, but not always, differences in other emissions-related components installed on California cars as opposed to cars delivered elsewhere. The ECM or PCM is an example of one area where, depending upon the specific drivetrain configuration, there may be a difference for California versus non-California cars.

[Terry M.]

Re: 1984 Coupe RPO code number

On 2008 Corvettes a California "certification" was required for cars sold/delivered in that state. I am sure there is a code for it, but I don't have the resources at hand to find it at the moment. Visually it consisted of a label under the hood that stated the car conformed to California emissions standards. I have been unable to verify if there was a computer difference.

2008 Corvettes brought into California without this certification were required to pass the emissions test or in the vernacular of the street: "be smogged." The interesting part of this is that as of the Summer of 2008, a little more than half way through the 2008 model year, there was not a single smog station in California that could smog test a 2008 Corvette due to the inability of the test equipment to communicate with the CAN system in the car. I am not sure if this situation has been corrected yet, or not, as I lost track of this situation during the Summer.

[Joe L.]

Re: 1984 Coupe RPO code number

On 2008 Corvettes a California "certification" was required for cars sold/delivered in that state. I am sure there is a code for it, but I don't have the resources at hand to find it at the moment. Visually it consisted of a label under the hood that stated the car conformed to California emissions standards. I have been unable to verify if there was a computer difference.

2008 Corvettes brought into California without this certification were required to pass the emissions test or in the vernacular of the street: "be smogged." The interesting part of this is that as of the Summer of 2008, a little more than half way through the 2008 model year, there was not a single smog station in California that could smog test a 2008 Corvette due to the inability of the test equipment to communicate with the CAN system in the car. I am not sure if this situation has been corrected yet, or not, as I lost track of this situation during the Summer.

Terry-----


The engine control module for all 2008 Corvettes is the same----GM #12612384. However, this may be a SERVICE-only part number and not necessarily the same part number as used in PRODUCTION. As a matter of fact, the GM #12612384 is used on a whole host of other 2008 GM models. The reason for all this commonality is that I think the unit has to be programmed before installation in the car. At the assembly plant, I think the computer is programmed in-plant for the specific application. The programming may or may not be different for California versus non-California cars. The factory service manual should reveal this.

[Terry M.]

Re: 1984 Coupe RPO code number

Terry-----


The engine control module for all 2008 Corvettes is the same----GM #12612384. However, this may be a SERVICE-only part number and not necessarily the same part number as used in PRODUCTION. As a matter of fact, the GM #12612384 is used on a whole host of other 2008 GM models. The reason for all this commonality is that I think the unit has to be programmed before installation in the car. At the assembly plant, I think the computer is programmed in-plant for the specific application. The programming may or may not be different for California versus non-California cars. The factory service manual should reveal this.

I got the three book, about 4-inch thick, 2008 service manual. I am keeping it in the plastic wrapper in the hope that will bring me good luck with the car. This is the first car I have owned that the potential of repairs intimidates me.

Any thoughts on where the computer information would be -- that is what section? I think one of the books has all the MIL codes and troubleshooting trees for those. If it is laid out like my 2001 Camaro manuals.

I have the build sheet for the new car. Maybe it has the ECM part number. I'll put it on my list of "info to get from the garage" on the first slightly warm day.

I hope we have answered the OP's question because we are wandering off course here.

[Joe L.]

Re: 1984 Coupe RPO code number

I got the three book, about 4-inch thick, 2008 service manual. I am keeping it in the plastic wrapper in the hope that will bring me good luck with the car. This is the first car I have owned that the potential of repairs intimidates me.

Any thoughts on where the computer information would be -- that is what section? I think one of the books has all the MIL codes and troubleshooting trees for those. If it is laid out like my 2001 Camaro manuals.

I have the build sheet for the new car. Maybe it has the ECM part number. I'll put it on my list of "info to get from the garage" on the first slightly warm day.

I hope we have answered the OP's question because we are wandering off course here.

Terry-----


I expect that the info will be in the "driveability and emissions" volume. However, that's usually a very thick volume and ALL the volumes have VERY THIN paper for the pages (so that they can cram everything that they need to into a stack ONLY 4 inches thick). You might try checking the index. However, most GM service manuals are VERY poorly indexed and it's often EXTREMELY difficult to find what you need by reference to the index.

A chilling thought: it's actually necessary to be familiar with and understand what's in that 4 inch stack of THIN pages in order to troubleshoot and repair these cars. Now, how many service technicians at Chevrolet dealerships do you think have read through and understand these manuals?

[Terry M.]

Re: 1984 Coupe RPO code number

Actually the SI (Service Information) is computerized and the techs use that system. It is far more extensive than the printed material. I know the techs can access the SI from locations other than their place of employment, but I haven't been able to work my way into that system. I can beg specific information on an as-needed basis, but I don't wish to abuse that for obvious reasons.

The printed service manuals for 2008 didn't come out until late Spring of 2008. The first 2008 Corvette production was in late June 2007 with full production beginning in July. The only information available for almost a year was the computerized SI. I understand this time lag is typical now days.

[Art A.]

Re: 1984 Coupe RPO code number

Actually the SI (Service Information) is computerized and the techs use that system. It is far more extensive than the printed material. I know the techs can access the SI from locations other than their place of employment, but I haven't been able to work my way into that system. I can beg specific information on an as-needed basis, but I don't wish to abuse that for obvious reasons.

The printed service manuals for 2008 didn't come out until late Spring of 2008. The first 2008 Corvette production was in late June 2007 with full production beginning in July. The only information available for almost a year was the computerized SI. I understand this time lag is typical now days.

Terry, Engineering used to publish a PRELIMINARY SM for internal usage only, early on in the production MY. It always had a white cover with black printing and was marked as "PRELIMINARY" . With that said, I'm sure that the computerized version that you mentioned is the primary working version used by the dealers now-a-days. The computerized version is a packaged deal sold to the dealers for big $, 1,200+$ so I'm told..........per vehicle line. So the printed copy is not a priority and gets published later.

BTW the SM are set up in the GM UPC, Unit Part Classification, format and are fairly easy to find things if you know the UPC system.