U0400 GMC Possible Causes
- Faulty Engine Control Module (ECM)
- Engine Control Module harness is open or shorted
- Engine Control Module circuit poor electrical connection
- Engine Control Module (ECM) not configured
First diagnose U0400 GMC code
Check 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 terminals.
Cost of diagnosing the U0400 GMC code
Labor: 1.0The cost of diagnosing the U0400 GMC code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle's make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
When is the U0400 GMC code detected?The control module is not configured properly.
U0400 GMC Possible Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
U0400 Gmc DescriptionSome control modules are constantly receiving information from other control modules through serial data communication network. The invalid data code will be set when a receiving control module detects a discrepancy in information it receives from another control module causing its integrity to be questioned. The symptom byte listed in the DTC Descriptor is for engineering reference only. No external circuit diagnosis is involved.
U0400 GMC More InformationNeed more information on how to fix the U0400 GMC code?
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U0400 GMC CommentsHelp us improve AutoCodes.com. Leave a comment below or tell us if the information above help you fix the code. What are the symptoms on your vehicle for the U0400 Gmc code? Have you replaced any parts?
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