Alternator output and power demand of all electrical loads and systems must be matched to each other as ideally as possible so that the entire system is reliable and trouble-free in operation. The PCM monitors alternator output deviation from the signal of the FR terminal of the alternator when the engine is running.
PCM sets DTC P0626 if the PCM detects output duty signal higher than the possible range of a properly operating alternator
Item
Detecting Condition
Possible Cause
DTC Strategy
Electrical Check
Open or short to ground in harness
Faulty charging system
Enable Conditions
Time after ignition ON > 0.1sec.
Engine stop
Threshold Value
Alternator load > 35%
Diagnostic Time
1sec.
MIL On Condition
-
Signal waveform at alternator #3 terminal
Fig.1) Normal waveform with IG ON
Fig.2) Normal waveform with Idle and no electrical load
Fig 3) Normal waveform with Idle and part electrical load
Fig.4) Normal waveform with Idle and full electrical load(A/C, Defrost, Head Lamp, Repeater, Audio, etc)