Circuit Inspection

Ignition SW "OFF".
Connect VMI to GDS and set up an oscilloscope as follow (2-channel);
Channel A (+): LIN terminal of battery sensor.

Channel A (-): Ground
Engine "ON".
Specification : See waveform below

Courtesy of HYUNDAI MOTOR AMERICA

Fig.1) Alternator Signal Waveform at idle and no electrical load.
Is the measured waveform within specification?
YES
- Fault is intermittent caused by poor contact in the sensor's and/or ECM's connector or was repaired and ECM memory was not cleared. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.
NO
- Carefully re-do this troubleshooting guide steps.
- If no problems were found with the circuits or connectors, replace the battery sensor and go to "Verification Of Repair " procedure.