K 2500 Suburban 4WD V8-5.7L VIN R (1999)
Information Bus: Reading and Clearing Diagnostic Trouble Codes
With Diagnostic Scan Tool
The procedure for reading diagnostic trouble code(s) is to use a diagnostic scan tool. Read Diagnostic Trouble Codes Using a Tech 1, Tech 2 or Other
Scan Tool.
When reading DTC(s), follow instructions supplied by tool manufacturer.
Without Diagnostic Scan Tool
A scan tool must be used to retrieve DTCs from the PCM/VCM memory. DTCs can no longer be retrieved by grounding terminals "A" to "B" at the
Data Link Connector (DLC). This also eliminates the PCM/VCM function of flashing Code 12. The use of a Tech 1 scan tool or equivalent will be
needed to obtain both current and history DTCs.
With Diagnostic Scan Tool
Important: Do not clear DTCs unless directed to do so by the service information provided for each diagnostic procedure. When DTCs are cleared, the
Freeze Frame data which may help diagnose an intermittent fault will also be erased from memory.
To clear Diagnostic Trouble Codes (DTCs), use the diagnostic scan tool "clear DTCs" or "clear info" function.
When clearing DTCs follow instructions supplied by the tool manufacturer.
Without Diagnostic Scan Tool
Important: Do not clear DTCs unless directed to do so by the service information provided for each diagnostic procedure. When DTCs are cleared, the
Freeze Frame data which may help diagnose an intermittent fault will also be erased from memory.
To clear Diagnostic Trouble Codes (DTCs), use the diagnostic scan tool "clear DTCs" or "clear info" function.
When clearing DTCs follow instructions supplied by the tool manufacturer.
When a scan tool is not available, DTCs can also be cleared by disconnecting one of the following sources for at least thirty (30) seconds:
Caution: To prevent system damage, the ignition key must be "OFF" when disconnecting or reconnecting battery power.
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The power source to the control module.
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The negative battery cable. (Disconnecting the negative battery cable may result in the loss of other on-board memory data, such as preset radio
tuning).
