Toyota Sienna Service Manual: Diagnosis Circuit
DESCRIPTION
DTC output mode is set by connecting terminals TC and CG of the DLC3.
DTCs are displayed by blinking the SRS warning light.
HINT:
- When each warning light stays blinking, a ground short in the wiring of terminal TC of the DLC3 or an internal ground short in each ECU is suspected.
- A DTC output mode signal is transmitted through BEAN and CAN to each ECU including the center airbag sensor assembly. Thus when all systems do not enter DTC output mode, there may be an ECM malfunction.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 CHECK MULTIPLEX COMMUNICATION SYSTEM
- Check if the multiplex communication system DTC is output.
HINT: The center airbag sensor assembly of this system is connected to the multiplex communication system.
Therefore, before starting troubleshooting, make sure to check that there is no trouble in the multiplex communication system.
OK: The Multiplex communication system DTC is not output.
2 CHECK CAN COMMUNICATION SYSTEM
- Use the intelligent tester to check if the CAN communication system is functioning normally.
HINT: The ECM is connected to the CAN communication system. Therefore, before starting troubleshooting, make sure to check that there is no trouble in the CAN communication system.
OK: The CAN communication system is functioning normally.
3 CHECK WIRE HARNESS (TC OF DLC3 - TC OF ECM)
- Turn the ignition switch to the LOCK position.
- Disconnect the connector from the ECM.
- Measure the resistance according to the value(s) in the table below.
Standard resistance
4 CHECK WIRE HARNESS (CG OF DLC3 - BODY GROUND)
- Measure the resistance according to the value(s) in the table below.
Standard resistance
5 CHECK WIRE HARNESS (TC OF DLC3 - BODY GROUND)
- Measure the resistance according to the value(s) in the table below.
Standard resistance
REPLACE CENTER AIRBAG SENSOR ASSEMBLY
SRS Warning Light does not Come ON
DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
1 CHECK BATTERY
Measure the voltage of the battery.
Standard voltage:
11 to 14 V
2 CHECK CONNECTORS
Turn the ignition switch to the LOCK ...
Other materials:
On-vehicle inspection
1. INSPECT DRIVE BELT
(a) Visually check the drive belt for excessive wear,
frayed cords, etc.
If any defect is found, replace the drive belt.
HINT:
Cracks on the rib side of a belt are considered
acceptable. Replace the belt if there are any
missing ribs.
2. CHECK POWER STEERING FLUID ...
Vehicle interior
Items
Check points
Accelerator pedal
The accelerator pedal should move
smoothly (without uneven pedal effort or
catching).
Automatic transaxle “Park”
mechanism
When parked on a slope with the shift
lever in P, is ...
Precaution
1. TIRE PRESSURE WARNING SYSTEM PRECAUTION
(a) When the tire pressure warning light comes on,
immediately check the tire pressure of the tire and
adjust it to the specified value. (The tire pressure
warning light will come on after blinking for 1 minute
if there is an open in the tire press ...
