DESCRIPTION
| Detection Item | Symptoms | Trouble Area |
|---|---|---|
| Power Steering ECU Communication Stop Mode | Either condition is met:
|
|
WIRING DIAGRAM
Figure 1. w/o Stop and Start System
Figure 2. w/ Stop and Start System
CAUTION / NOTICE / HINT
Note
Because the order of diagnosis is important to allow correct diagnosis, make sure to begin troubleshooting using How to Proceed with Troubleshooting when CAN communication system related DTCs are output.
Before measuring the resistance of the CAN bus, turn the engine switch off and leave the vehicle for 1 minute or more without operating the key, switches or opening or closing the doors. After that, disconnect the cable from the negative (-) battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.
After turning the engine switch off, waiting time may be required before disconnecting the cable from the battery terminal. Therefore, make sure to read the disconnecting the cable from the battery terminal notice before proceeding with work.
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
DTC check procedure: Turn the engine switch on (IG) and wait at least 12 seconds.
After the repair, perform CAN Bus Check and check that all the ECUs and sensors connected to the CAN communication system are displayed.
Tech Tips
Operating the engine switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.
Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below may help determine the cause of the malfunction.
PROCEDURE
CHECK VEHICLE TYPE
Check vehicle type.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
CHECK FOR OPEN IN CAN BUS WIRE (POWER STEERING ECU ASSEMBLY BRANCH WIRE) Click here |
| A |
|
CHECK FOR OPEN IN CAN BUS WIRE (POWER STEERING ECU ASSEMBLY BRANCH WIRE)
| *a | Front view of wire harness connector (to Power Steering ECU Assembly) |
Disconnect the cable from the negative (-) battery terminal.
Disconnect the power steering ECU assembly connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| NG |
|
CHECK FOR OPEN IN CAN BUS WIRE (POWER STEERING ECU ASSEMBLY BRANCH WIRE) Click here |
| OK |
|
CHECK HARNESS AND CONNECTOR (BATTERY - ECU WIRE SUB-ASSEMBLY)
| *a | Front view of wire harness connector (to ECU Wire Sub-assembly) |
Reconnect the cable to the negative (-) battery terminal.
Note
When disconnecting the cable, some systems need to be initialized after the cable is reconnected.
Disconnect the ECU wire sub-assembly connector.
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | ||||||
|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
CHECK HARNESS AND CONNECTOR (BATTERY - ECU WIRE SUB-ASSEMBLY)
| *a | Front view of wire harness connector (to ECU Wire Sub-assembly) |
Disconnect the ECU wire sub-assembly connector.
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | ||||||
|---|---|---|---|---|---|---|
|
||||||
|
| Result | ||||||||
|---|---|---|---|---|---|---|---|---|
|
| B |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| C |
|
CHECK HARNESS AND CONNECTOR (ECU WIRE SUB-ASSEMBLY - ENGINE STOP AND START ECU) Click here |
| A |
|
CHECK ECU WIRE SUB-ASSEMBLY
| *a | Front view of wire harness connector (to Power Steering ECU Assembly) |
Reconnect the ECU wire sub-assembly connectors.
Disconnect the power steering ECU assembly connectors.
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
|||||||||
|
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE POWER STEERING ECU ASSEMBLY Click here |
| NG |
|
REPLACE ECU WIRE SUB-ASSEMBLY Click here |
CHECK FOR OPEN IN CAN BUS WIRE (POWER STEERING ECU ASSEMBLY BRANCH WIRE)
| *a | Front view of wire harness connector (to Power Steering ECU Assembly) |
Disconnect the ECU wire sub-assembly connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE ECU WIRE SUB-ASSEMBLY Click here |
| NG |
|
REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (POWER STEERING ECU ASSEMBLY) |
CHECK HARNESS AND CONNECTOR (ECU WIRE SUB-ASSEMBLY - ENGINE STOP AND START ECU)
Disconnect the I57 engine stop and start ECU connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| OK |
|
GO TO STOP AND START SYSTEM Click here |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
CHECK FOR OPEN IN CAN BUS WIRE (POWER STEERING ECU ASSEMBLY BRANCH WIRE)
| *a | Front view of wire harness connector (to Power Steering ECU Assembly) |
Disconnect the cable from the negative (-) battery terminal.
Disconnect the power steering ECU assembly connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| NG |
|
CHECK FOR OPEN IN CAN BUS WIRE (POWER STEERING ECU ASSEMBLY BRANCH WIRE) Click here |
| OK |
|
CHECK HARNESS AND CONNECTOR (BATTERY - ECU WIRE SUB-ASSEMBLY)
| *a | Front view of wire harness connector (to ECU Wire Sub-assembly) |
Reconnect the cable to the negative (-) battery terminal.
Note
When disconnecting the cable, some systems need to be initialized after the cable is reconnected.
Disconnect the ECU wire sub-assembly connector.
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | ||||||
|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
CHECK HARNESS AND CONNECTOR (BATTERY - ECU WIRE SUB-ASSEMBLY)
| *a | Front view of wire harness connector (to ECU Wire Sub-assembly) |
Disconnect the ECU wire sub-assembly connector.
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | ||||||
|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
CHECK ECU WIRE SUB-ASSEMBLY
| *a | Front view of wire harness connector (to Power Steering ECU Assembly) |
Reconnect the ECU wire sub-assembly connectors.
Disconnect the power steering ECU assembly connectors.
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE POWER STEERING ECU ASSEMBLY Click here |
| NG |
|
REPLACE ECU WIRE SUB-ASSEMBLY Click here |
CHECK FOR OPEN IN CAN BUS WIRE (POWER STEERING ECU ASSEMBLY BRANCH WIRE)
| *a | Front view of wire harness connector (to Power Steering ECU Assembly) |
Disconnect the ECU wire sub-assembly connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE ECU WIRE SUB-ASSEMBLY Click here |
| NG |
|
REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (POWER STEERING ECU ASSEMBLY) |