Trouble Code Types and Reset Counter

NOTE: A Diagnostic Trouble Code (DTC) indicates the PCM has recognized an abnormal condition in the system. Diagnostic trouble codes are the results of a system or circuit failure, but do not directly identify the failed component or components.

Each diagnostic trouble code is diagnosed by following a specific testing procedure. The diagnostic charts contain step-by-step instructions for determining the cause of trouble codes as well as no trouble code problems. It is not necessary to perform all of the diagnostic chart tests to diagnose an individual code.

Always begin by reading the diagnostic trouble codes using a scan tool.
- This procedure begins in Diagnostic Charts/Trouble Code Tests/DTC TEST - Checking the System for Diagnostic Trouble Codes. This will direct you to the specific test(s) that must be performed. DTC Test - CODE TO TC TEST CHART (Checking for Trouble Codes)

Hard Codes
A diagnostic trouble code that comes back within one cycle of the ignition key is a "hard" code. This means that the defect is there every time the powertrain control module checks that circuit or function. Procedures in this manual verify if the trouble code is a hard code at the beginning of each test. When it is not a hard code, an "intermittent" test must be performed.

Intermittent Codes
A diagnostic trouble code that is not there every time the powertrain control module checks the circuit is an "intermittent" code. Most intermittent codes are caused by wiring or connector problems. Defects that come and go like this are the most difficult to diagnose; they must be looked for under specific conditions that cause them. The following checks may assist you in identifying a possible intermittent problem:
- Visually inspect related wire harness connectors. Look for broken, bent, pushed out, or corroded terminals.
- Visually inspect the related harnesses. Look for chafed, pierced, or partially broken wire.
- Refer to any technical service bulletins that may apply.

Reset Counter
The reset counter counts the number of times the vehicle has been started since codes were last set, erased, or the battery was disconnected. The reset counter will count up to 255 start counts. The number of starts helps determine when the trouble code actually happened. This is recorded by the PCM and can be viewed on the scan tool as the RESET COUNTER.

When there are no trouble codes stored in memory, the DRB will display "NO TROUBLE CODES FOUND" and the reset counter will show "RESET COUNT = XXX."