Fix P0626: STEP-BY-STEP diagnostic GUIDE!

The P0626: Generator Field/F Terminal Circuit High code indicates that the vehicle’s control module has detected excessively high voltage in the generator field (or F terminal) circuit. This may result from a faulty generator field terminal, high voltage supply, or wiring problems that can affect the vehicle’s charging system.

P0626 – Quick Overview

CodeInformation
MeaningP0626: Generator Field/F Terminal Circuit High
Is it serious?Yes, as it may indicate issues with the charging system.
Possible causes– Faulty generator field/F terminal
– High voltage in circuit
– Wiring issue
How to diagnose?– Test generator field/F terminal for high voltage
– Inspect wiring and connectors
– Replace generator field/F terminal if necessary

P0626 Meaning

The P0626 code indicates that the generator field (F terminal) circuit is experiencing higher-than-expected voltage. The generator field terminal controls the alternator’s output, and if it detects a high voltage, it can cause charging system malfunctions. This can result in overcharging of the battery, which may lead to further electrical issues.

Step-by-step diagnostic guide

ActionDescriptionTools Needed
Check for Other CodesUse an OBD-II scanner to check for additional codes related to the charging system, as they might help pinpoint the issue.OBD-II Scanner
Test the Generator Field/F Terminal for High VoltageUse a multimeter to measure the voltage at the generator field (F terminal) to determine if it is within the correct range.Multimeter
Inspect Wiring and ConnectorsInspect the wiring and connectors associated with the generator field/F terminal for damage, loose connections, or corrosion.Flashlight, Multimeter
Test the Generator (Alternator)If necessary, test the generator or alternator to verify it is functioning properly and not contributing to the high voltage.Diagnostic Tool, Multimeter
Replace the Generator Field/F Terminal if NecessaryIf the field terminal is faulty or contributing to the high voltage, replace it to restore proper voltage control in the charging system.Replacement Terminal, Tools
Clear the Code and TestAfter completing repairs, clear the code using an OBD-II scanner and test the vehicle to ensure the charging system functions properly.OBD-II Scanner, Vehicle Manual
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