Celica L4-1.8L (2ZZ-GE) (2005)
1. Disconnect connectors "A" and "C" and measure the resistance between terminals 1 and 2 of connector "A" and the body ground.
In the case of Fig. 6:
Between terminal 1 of connector "A" and body ground -> Continuity (short)
Between terminal 2 of connector "A" and body ground -> No continuity
Therefore, it is found out that there is a short circuit between terminal 1 of connector "A" and terminal 1 of connector "C".
2. Disconnect connector "B" and measure the resistance between terminal 1 of connector "A" and body ground, and terminal 1 of connector "B2"
and body ground.
In the case of Fig. 7:
Between terminal 1 of connector "A" and body ground -> No continuity
Between terminal 1 of connector "B2" and body ground -> Continuity (short)
Therefore, it is found out that there is a short circuit between terminal 1 of connector "B2" and terminal 1 of connector "C".
8. CHECK AND REPLACE ECU
First check the ECU ground circuit. If it is faulty, repair it. If it is normal, the ECU could be faulty. So replace the ECU with a normal functioning
one and check if the symptoms appear.
1. Measure the resistance between the ECU ground terminal and the body ground.
Resistance: 1 ohm or less