RPO/Model Usage

General Motors Corporation produces an array of Options on their vehicles allowing the consumer choices in selecting the vehicle which most fits their needs. This means to the technician, that he/she must deal with the differences between two vehicles with the same year, make, model and engine combinations. General Motors has provided on their vehicles a Regular Production 0ption or RP0 code label. The RP0 code can be very useful in identifying systems which exist on specific vehicles. Regular Production Option (RPO)

The RP0 code label contains a code that identifies the type of transmission the vehicle was manufactured with. 0ne example is a 1996 vehicle which indicates on the RP0 label the code M30. The M30 indicates that the vehicle is equipped with a 4L60-E automatic transmission. The transmission type contains information regarding some of the specifics applicable to the transmission. The "4" in 4L60-E indicates that the unit is a 4 speed, the "L" indicates the unit is a longitudinal mount, the "60" indicates production series and the "E" indicates that the unit is electronic. This distinction can usually be achieved by identifying the transmission oil pan configuration. Pan Configuration

Typical maintenance and service of these units rarely require more than identifying the type of transmission; however, in some more complicated procedures, oil pressure readings, internal parts, exact shift points and specifications, it is important to identify the specific model code.

The model code is either stamped into a plate which is attached to the transmission housing or it is stamped directly into the housing. The code typically consists of 4 characters. The first character is a numeric digit which reflects the date of manufacture. The remaining 3 characters are usually alpha characters and reveal specific model build information.

Example:
A 1997 Pontiac Bonneville with an engine vin K, has a 3.8L engine. This year, make, model and engine combination is available with transmission RP0 code M13. The Ml3 RP0 code indicates a 4T60-E automatic transaxle. Investigation of the model information reveals that there are two 4T60-E automatic transaxle models available for 1997 Pontiac Bonneville with the 3.8L engine vin K. 0ne is the 7ACW which has a final drive ratio of 3.06. The other is a 7ASW which has a final drive ratio of 2.84.

Note:
In the example above, specific model build information would not be required to service the transaxle; however, if the task were to overhaul the assembly, specific model build information would be required to ensure correctly matched parts, specifications and proper operation of the unit.

Alldata transmission information is identified by model code only when there is a difference between available options. Component and Information types which do not require specific model code information will be designated by transmission type. Vehicles which do not have optional transmission information will display without regard to transmission type or model code.