B1004 GMC - Keep Alive Memory
B1004 GMC Possible Causes
- Faulty Control Module
- Control Module harness is open or shorted
- Control Module circuit poor electrical connection
How do I fix code B1004 GMCCheck the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.
Cost of diagnosing the B1004 GMC code
Labor: 1.0The cost of diagnosing the B1004 GMC code is 1.0 hour of labor. The auto repair labor rates vary widely across the country, and even within the same city. Most auto repairs shops charge between $75 and $150 per hour.
- Engine Light ON (or Service Engine Soon Warning Light)
B1004 GMC MeaningThis fault is internal. No external circuits are involved. Module microprocessor must be active/awake for the Diagnostic Trouble Code (DTC) to set. The microprocessor calculates the checksum on those areas of memory that hold critical operation data. This is done at a regular interval and is called a periodic checksum. The microprocessor also calculates a checksum on these memory locations whenever new data is written to them. This is called the running checksum. The microprocessor compares periodic checksum to running checksum. If they do not match, the microprocessor sets DTC B1004.
When DTC is set, microprocessor reverts back to base programmed critical operating data until new data is learned and stored in Keep Alive Memory (KAM). DTC will clear when the microprocessor calculates a successful comparison of periodic checksum to running checksum.
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