|
Diagnostic Trouble Codes for OBD II (OBD2) equipped General Motors (GMC, Chevrolet, Buick, Oldsmobile, Cadillac, Pontiac, Saturn) vehicles. Updated through the 2004 model year.
All cars and light trucks built and sold in the United States after January 1, 1996 were required to be OBD II equipped. In general, this means all 1996 model year cars and light trucks are compliant, even if built in late 1995. Some 1995 model year vehicles are also equipped with OBDII - although some pre-1996 OBD-II cars are not 100% compliant. Pre-OBD-II cars had connectors in various positions under the dashboard and under the hood. All OBD-II cars have a connector located in the passenger compartment easily accessible from the driver's seat.
GM cars and light trucks use SAE J1850 VPW (Variable Pulse Width Modulation). There are some variations among imports such as the Cadillac Catera, which is a German Opel derivative, the Catera uses the European ISO 9141 protocol.
A cable is plugged into the OBD-II J1962 connector and the other end is connected to a scan tool. A hand-held scan tool is usually limited to one OBD-II system type - there are three basic OBD-II protocols in use, each with minor variations on the communication pattern between the on-board diagnostic computer and the scan tool. In general, Chrysler products and all European and most Asian imports use ISO 9141 circuitry. GM cars and light trucks use SAE J1850 VPW (Variable Pulse Width Modulation), and Fords use SAE J1850 PWM (Pulse Width Modulation) for communication.
A complete driving cycle will perform diagnostics on all monitored systems and can usually be completed in less than fifteen minutes.
How the Diagnostic Trouble Code is created: A DTC is made up of 5 digits. The chart below shows the composition of a DTC. With this information you can easily determine what system to trouble shoot without knowing the exact description of the code.
X X X X X
| | | |
| | | |
B Body ----------+ | | +-- Fault (00 to 99)
C Chassis -------+ | |
P Powertrain ----+ | |
U Network -------+ | +------ 1 Fuel & Air Metering
| +------ 2 Fuel & Air Metering (Injector)
| +------ 3 Ignition System or Misfire
0 SAE --------------+ +------ 4 Auxiliary Emission Controls
1 MFG --------------+ +------ 5 Vehicle Speed & Idle Control System
+------ 6 Computer Output Citcuit
+------ 7 Transmission
+------ 8 Transmission
+------ 9 Reserved
+------ 0 Reserved
Using the Cadillac on-board diagnostic display you'll also see "IP" for the IPC instrument panel, "AC" for the air conditioning module, "TC" for traction control, "RS" for the road suspension system, "SD" for the air bags, "PZ" for the body control module, "CC" for the cell phone and "RF" for the integrated radio.
There are two categories of DTC's that apply to OBDII.
The Official eGroups Cadillac Owners mailing list is an automatically maintained email mailing list and archive dedicated to the distribution of general information, questions, inquiries about new Cadillac Motor Cars and related topics. Here you'll find owner comments and critiques, articles showing how owners maximize performance, stories of unique owner experiences and news of accessories, recalls, service bulletins, links to other valuable websites and other important information. Whether you presently own a Cadillac or are looking to purchase one this list is for you! Alternatively, you can send a blank email message to: Consider this mailing list a real-time supplement to the Cadillac Vision Magazine every new Cadillac owner receives.
|