2007 TOYOTA SIENNA Service Repair Manual

Page 65 of 3000

TOYOTA SIENNA 2007  Service Repair Manual INTRODUCTION  –  HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMSIN–35
IN
(a) First, check the ECU ground circuit. If it is faulty, 
repair it. If it is normal, the ECU could be faulty. 
Temporarily rep

Page 66 of 3000

TOYOTA SIENNA 2007  Service Repair Manual IN–36INTRODUCTION  –  HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS
IN
HOW TO PROCEED WITH 
TROUBLESHOOTING
1. OPERATION FLOW
HINT:
Perform troubleshooting in accordance with the 
procedures below. T

Page 67 of 3000

TOYOTA SIENNA 2007  Service Repair Manual INTRODUCTION  –  HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMSIN–37
IN
(a) Check the results obtained in step 4. Then find the 
output DTC in the DTC chart. Look at the "Trouble Area" 
column

Page 68 of 3000

TOYOTA SIENNA 2007  Service Repair Manual IN–38INTRODUCTION  –  HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS
IN
HINT:
• In troubleshooting, confirm that the problem symptoms 
have been accurately identified. Preconceptions should be 
disc

Page 69 of 3000

TOYOTA SIENNA 2007  Service Repair Manual INTRODUCTION  –  HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMSIN–39
IN
• In the DTC check, it is very important to determine 
whether the problem indicated by the DTC either: 1) 
still occurs, or 2

Page 70 of 3000

TOYOTA SIENNA 2007  Service Repair Manual IN–40INTRODUCTION  –  HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS
IN
• The following flowchart shows how to proceed with 
troubleshooting using the DTC check. Directions from 
the flowchart will

Page 71 of 3000

TOYOTA SIENNA 2007  Service Repair Manual INTRODUCTION  –  HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMSIN–41
IN
If a DTC was displayed in the initial DTC check, the 
problem may have occurred in a wire harness or 
connector in that circuit

Page 72 of 3000

TOYOTA SIENNA 2007  Service Repair Manual IN–42INTRODUCTION  –  HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS
IN
(a) VIBRATION METHOD: When a malfunction seems 
to occur as a result of vibration.
(1) PART AND SENSOR
Apply slight vibration wi