Connect GDS to DLC(Data Link Cable).
Warm up the engine to normal operating temperature.
Check the "Current Data" about related DTC with GDS.
Fig.1) Engine Idle after Warm Up & Aircon "On"
A: Engine Idle after Warm Up
B: Aircon "On"
Fig.2) Approx. 2000RPM & At Acceleration
A: Approx. 2000RPM
B: At Acceleration
If the parameter is not simular with shown data, measure related waveforms with GDS.
Fig.1) Engine Idle after Warm Up
COM → Duty(+) Approx. 34%
Duty(-) Approx. 66%,
FR → Duty(+) Approx. 58%
Duty(-) Approx. 42%,
Fig.2) Electrical Load(Engine Idle after Warm Up)
COM → Duty(+) Approx. 34%
Duty(-) Approx. 66%,
FR → Duty(+) Approx. 96%
Duty(-) Approx. 4%,
Duty(+) from FR terminal is increased if electrical loads are ON(Head Lamp and Defrost are ON) ECM controls generation of alternator with duty from FR terminal when electrical Loads turn on.
Does the Alternator operate properly? (Check variation)
![]() | ▶ Go to "Verification of Vehicle Repair" procedure. |
![]() | ▶ Substitute with a known-good Alternator and check for proper operation. If the problem is corrected, replace Alternator and then go to "Verification of Vehicle Repair" procedure. |