GM RPO code lookup and decoder

[markopolo]

Online GM RPO lookup and decoder here:

http://www.cadillacfaq.com/rpo/index.php

Very nice! Enter all your RPO codes from the Service Parts Identification (SPID) sticker on your GM vehicle. (My sticker was on the passenger door)

Separate codes by a comma AK5,AS5,B38,C60 etc. no spaces, and enter them and the report looks like this:

RPO Code Explanation/Description
AK5 RESTRAINT SYSTEM SEAT, INFLATABLE, DRIVER & PASS
AS5 SEAT FRT BKT, DELUXE,
B38 COVERING FLOOR VINYL, FRT & RR, FULL WIDTH
C60 HVAC SYSTEM AIR CONDITIONER FRT, MAN CONTROLS
E23 GVW RATING 9,500 LBS
GT4 AXLE REAR 3.73 RATIO
JB8 BRAKE POWER, DISC/DRUM, 10,000 LBS
KW2 GENERATOR 124 AMP
L65 ENGINE DIESEL, 8 CYL, 6.5L, TURBO, HO
MT1 TRANSMISSION AUTO 4 SPD, HMD, 4L80-E
UM7 RADIO AM/FM STEREO, SEEK/SCAN, CLOCK, ETR
YHH TIRE REAR LT245/75R16/E BW R/PE ST TL ALS 120Q
ZHH TIRE SPARE LT245/75R16/E BW R/PE ST TL ALS 120Q

That is just a portion of the results. The sticker on my van had approx 50 codes.

[markopolo]

Just bumping this post up. I find decoding the RPO codes sticker on the van to be very useful.
You only need to do it once and save the results. I have a text file of the results that I refer to often.

Yesterday I wanted to identify the cooling system parts (before I start taking (the wrong) things apart ). I saw an auxiliary transmission fluid cooler and power steering fluid cooler but there was another cooler similar in size to the auxiliary transmission fluid cooler located below the radiator. In this van the A/C condenser mounts behind the radiator (pretty sure). It turns out the mystery cooler is an auxiliary engine oil cooler.

Both the auxiliary engine oil cooler and the auxiliary transmission fluid cooler are listed in RPO codes sticker on my van.
V14 R OIL, TRANSMISSION, AUX
V16 R OIL, ENGINE, AUX

Has anyone else here entered their RPO codes and looked at or saved the results?
Are there codes like this on Ford, Dodge and Mercedes? Please provide a link if you know of a decoder like this for these brands.

[booster]

Originally Posted by markopolo

Just bumping this post up. I find decoding the RPO codes sticker on the van to be very useful.
You only need to do it once and save the results. I have a text file of the results that I refer to often.

Yesterday I wanted to identify the cooling system parts (before I start taking (the wrong) things apart ). I saw an auxiliary transmission fluid cooler and power steering fluid cooler but there was another cooler similar in size to the auxiliary transmission fluid cooler located below the radiator. In this van the A/C condenser mounts behind the radiator (pretty sure). It turns out the mystery cooler is an auxiliary engine oil cooler.

Both the auxiliary engine oil cooler and the auxiliary transmission fluid cooler are listed in RPO codes sticker on my van.
V14 R OIL, TRANSMISSION, AUX
V16 R OIL, ENGINE, AUX

Has anyone else here entered their RPO codes and looked at or saved the results?
Are there codes like this on Ford, Dodge and Mercedes? Please provide a link if you know of a decoder like this for these brands.

I did ours, and it is very useful information to have around, especially if you are getting parts in the aftermarket. One thing it did not do for me was identify which rear axle was in it. It gave the ratio, and the limited slip code was not shown, but in the repair manual there are about 3-5 variants, so I still don't know for sure which it is. I am going to look closer for a tag on the axle, but it may be gone because GM already rebuilt it once.

[markopolo]

Same here re: the rear axle / differential. Mine is the 10.5" ring gear 14 bolt GM casing and I know the ratio but that is all I have found out.
RPO code G80 would indicate that it is a "locker" I think. I don't have RPO G80. I couldn't find a drain on the housing but will look again today.
There are some TSB's that warn against using RTV silicone as a gasket if you switch to synthetic gear oil. I'm just going to stay with 80W-90 oil for now.

[booster]

Originally Posted by markopolo

Same here re: the rear axle / differential. Mine is the 10.5" ring gear 14 bolt GM casing and I know the ratio but that is all I have found out.
RPO code G80 would indicate that it is a "locker" I think. I don't have RPO G80. I couldn't find a drain on the housing but will look again today.
There are some TSB's that warn against using RTV silicone as a gasket if you switch to synthetic gear oil. I'm just going to stay with 80W-90 oil for now.

No drain on ours either (may try to add one if there is room), probably the same 14 bolt 10.5" rear. Interesting on the no RTV with synthetic gear oil, as GM has gone to using synthetic (ours calls it out by GM number). I will have to check the service manual and see what sealer they recommend. I may try to suction it out through the fill hole, which works on some differentials. If not, I hope the cover will clear the generator so I can get it off.