OBD II Diagnostic Trouble Codes (DTCs)

OBD II regulations require that test modes and Diagnostic Trouble Codes (DTCs) be standardized between all automotive manufacturers. Saab first began to use the new five-character code structure in 1993 beginning with the TRIONIC system and has implemented it on all new systems introduced since then.

As shown above the first character in a OBD II DTC is a letter. This letter identifies the area of the vehicle the code applies to.

P - Powertrain
C - Chassis
B - Body

The second character indicates whether the code is a generic one as defined by SAE or a unique code specific to one manufacturer.

0 - Generic
1 - Manufacturer Specific

The third character identifies a specific vehicle system. Each system in the vehicle is assigned a series designation such as 100, 200. 300, and so on. These series are defined as follows:

100 - Fuel and Air Metering
200 - Fuel and Air Metering
300 - Ignition System or Misfire
400 - Auxiliary Emissions Controls
500 - Vehicle Speed Control and Idle Control System
600 - Computer Output Circuits
700 - Transmission
800 - Transmission

The final two characters are the actual codes which fall within the 100 series designator.