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.
P0625 is set when the PWM signal(Low side) in FR circuit is below 80% during engine stop state.
P0625 is set when the PWM signal(Low side) in FR circuit is below 3% during engine running state.
Item | Detecting Condition | Possible Cause | |
Case 1 | DTC Strategy |
•
IG ON | 1. Circuit shorts to ground 2. 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 < 80%
•
Minimum voltage of Low level duty signal ≥ 1.5V | ||
Diagnostic Time |
•
1 Second | ||
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 < 3% | ||
Diagnostic Time |
•
20 Seconds | ||
Mil On Condition |
•
No MIL | ||
① Normal waveform with IG ON
② Normal waveform with Idle and no electrical load
③ Normal waveform with Idle and part electrical load
④ Normal waveform with Idle and full electrical load(A/C, Defrost, Head Lamp, Repeater, Audio, etc)
