10) DTC FORMAT
- Diagnostic Trouble Code (SAE J2012)
- DTCs used in OBD-II vehicles will begin with a letter and are followed by four numbers.
The letter of the beginning of the DTC identifies the function of the monitored device that has failed. A "P" indicates a powertrain device, "C" indicates a chassis device. "B" is for body device and "U" indicates a network or data link code. The first number indicates if the code is generic (common to all manufacturers) or if it is manufacturer specific. A "0" & "2" indicates generic, "1" indicates manufacturer-specific. The second number indicates the system that is affected with a number between 1 and 7.
The following is a list showing what numbers are assigned to each system.
- Fuel and air metering
- Fuel and air metering (injector circuit malfunction only)
- Ignition system or misfire
- Auxiliary emission controls
- Vehicle speed controls and idle control system
- Computer output circuits
- Transmission
The last two numbers of the DTC indicates the component or section of the system where the fault is located.
PCM PROBLEM INSPECTION PROCEDURE
- TEST PCM GROUND CIRCUIT: Measure resistance between PCM and chassis ground using the backside of PCM harness connector as PCM side check point. If the problem is found, repair it. Specification (Resistance): 1ohms or less
- TEST PCM CONNECTOR: Disconnect the PCM connector and visually check the ground terminals on PCM side and harness side for bent pins or poor contact pressure. If the problem is found, repair it.
- If problem is not found in Step 1 and 2, the PCM could be faulty. If so, replace the PCM with a new one, and then check the vehicle again. If the vehicle operates normally then the problem was likely with the PCM.
- RE-TEST THE ORIGINAL PCM: Install the original PCM (may be broken) into a known-good vehicle and check the vehicle. If the problem occurs again, replace the original PCM with a new one. If problem does not occur, this is intermittent problem (Refer to «INTERMITTENT PROBLEM PROCEDURE»(ref-269586-S01444355212007110100000) in «BASIC INSPECTION PROCEDURE»(ref-269586-S32784161282007110100000) ).