The alternator is duty controlled as current control by ECM with the battery voltage, current, temperature information from battery sensor. The more electrical load, the higher duty output.
If it is open or short in COM circuit of alternator. ECM sets DTC.
Item | Detecting Condition | Possible cause | |
DTC Strategy |
•
Voltage monitoring |
•
Poor connection
•
Open or short in circuit
•
Faulty PCM | |
Enable Conditions | Case1 |
•
Engine running | |
Case2 |
•
Igintion ON | ||
Threshold value | Case1 |
•
Alternator COM line shorted ground or power | |
Case2 |
•
Alternator COM line open | ||
Diagnosis Time |
•
5 sec | ||
MIL On Condition |
•
DTC only (NO MIL ON) |
Fig.1) Normal waveforms of COM, FR terminal of alternator at idle.
Fig.2) Normal waveforms of COM, FR terminal of alternator under high electronic load condition
Fig.3) Normal waveforms of COM, FR terminal of alternator at ig on under connector disconnected condition.
Fig.4) Normal waveforms of COM, FR terminal of alternator at idle under connector disconnected condition.