PCM monitors the normality of PWM signal in alternator's FR circuit by comparing with the criterion value under IG ON state.
The signal duty is directly propotional to electrical load.
P0626 is set when the PWM signal(Low side) in FR circuit is above 95% during engine stop state.
P0626 is set when the PWM signal(Low side) in FR circuit is above 97% during engine running state.
Item | Detecting Condition | Possible Cause | |
Case 1 | DTC Strategy |
•
IG ON |
•
Circuit shorts to ground
•
Charging system |
Enable Conditions |
•
More than 3 sec after IG ON
•
Engine stop
•
No fault on a main rely
•
10 V＜ Battery voltage ＜ 16 V | ||
Threshold Value |
•
FR circuit Duty > 95% | ||
Diagnostic Time |
•
1 sec. | ||
Case 2 | DTC Strategy |
•
Engine running | |
Enable Conditions |
•
More than 100 sec after engine running
•
Engine RMP : 600rpm ~ 4000rpm
•
No fault on a main rely
•
10 V ＜ Battery voltage ＜ 16 V | ||
Threshold Value |
•
FR circuit Duty > 97% | ||
Diagnostic Time |
•
20 sec. | ||
Mil On Condition |
•
No MIL | ||
The normal FR circuit duty signal under engine running state
→ 5% < FR circuit duty < 95% : Normality , FR circuit duty < 3% : Abnormality
