The DTC value will help you narrow down the specific component or module in question. A DTC has a standardized format that can be interpreted as follows:
The first part of the DTC is the Alpha Designator. The alpha
designator can be:

B - Body electronics (i.e., door and hood latches)
C - Chassis (i.e., traction control or ABS)
P - Powertrain (i.e., engine, transmission, or engine support components)
U - Network communications for the different control models

The second part of the DTC, is a three or four-digit numerical series. The OBD-II specification has reserved the first 1,000 entries for a core set that are uniformly implemented across all vehicle manufacturers. DTCs after the core set are available for manufacturer specific uses.

Type of Code will be 0 for the core set, or a value of 1 - 9 for manufacturer specific codes. The Indicated System and Specific Code Number further narrow down the code to a specific component or system.

Powertrain Codes:

Network Codes

Body & Chassis Codes

Powertrain Codes:

P0001-P0099 P0100-P0199 P0200-P0299 P0300-P0399 P0400-P0499

Network Codes:

U0001-U0099 U0100-U0235 U0300-U0431

Body & Chassis Codes:

B1200-B1299 B1300-B1399 B1400-B1499 C0000-C0896

Action Taken When the DTC Sets – Type A  

• The Malfunction Indicator Lamp (MIL) will be illuminated as soon as the error occurs.
• The ECM will record operating conditions at the time the diagnostic fails. The information will be stored in the freeze frame and failure records buffers.
  A history DTC is stored.

Action Taken When the DTC Sets – Type B (or E) 

• The Malfunction Indicator Lamp (MIL) will be illuminated after 2 (or 3) valid driving cycles.
• The ECM will record operating conditions at the time the diagnostic fails. The information will be stored in the freeze frame and failure records buffers.
• A history DTC is stored.

Conditions for Clearing the MIL/DTC – Type A or Type B (or E)

• The MIL will turn off after four consecutive driving cycles in which the diagnostic runs without a fault.
• A history DTC will clear after 40 consecutive warm up cycles without a fault.
• DTC(s) can be cleared by using the scan tool.

Action Taken When the DTC Sets – Type Cnl

• The Malfunction Indicator Lamp (MIL) will not illuminate.
• The ECM will record operating conditions at the time the diagnostic fails.
• The information will be stored in the freeze frame and failure records buffers.

• A history DTC will clear after 40 consecutive warm up cycles without a fault.
• DTC(s) can be cleared by using the scan tool.

When DTCs are cleared, the Freeze Frame and Failure Record data which may help diagnose an intermittent fault will also be erased from memory. If the fault that caused the DTC to be stored into memory has been corrected, the Diagnostic Executive will begin to count the warmup cycles with no further faults detected, the DTC will automatically be cleared from the engine control module (ECM) memory.

To clear DTCs, use the diagnostic scan tool.

To prevent ECM damage, the key must be OFF when disconnecting or reconnecting the power to the ECM (for example battery cable, ECM pigtail connector, ECM fuse, jumper cables, etc.). When the ECM sets a Diagnostic Trouble Code (DTC), the Malfunction Indicator Lamp (MIL) lamp will be turned on only for type A, B and E but a DTC will be stored in the ECM s memory for all types of DTC. The DTC will stay in the ECM s memory until cleared by scan tool. DTCs should be cleared after repairs have been completed. Some diagnostic tables will tell you to clear the codes before using the chart. This allows the ECM to set the DTC while going through the chart, which will help to find the cause of the problem more quickly.

Pin 1 - (Some Applications - ECU Ignition live signal)
Pin 2 - J1850 Bus+
Pin 4 - Chassis Ground
Pin 5 - Signal Ground
Pin 6 - CAN High (J-2284)
Pin 7 - ISO 9141-2 K Line
Pin 10 - J1850 Bus
Pin 14 - CAN Low (J-2284)
Pin 15 - ISO 9141-2 L Line
Pin 16 - Battery Power