DTC Troubleshooting: 4
LKAS Control Unit DTC 4:
 A Problem with the Steering Angle Sensor Z Phase
NOTE: Information marked with an asterisk ( *1 ) applies to LHD model, an asterisk ( *2 ) applies to RHD model.
  1. Turn the ignition switch to LOCK (0), then turn it to ON (II).
  1. Turn the steering wheel 360 degrees to the right, and wait 20 seconds or more.
  1. Watch the LKAS indicator.
Does the LKAS indicator come on?
YES -
Go to Step 5 .
NO -
Intermittent failure, the system is OK at this time.■
Is DTC 4 indicated?
YES -
Go to Step 6 .
NO -
Troubleshoot the indicated DTC(s).■
  1. Turn the ignition switch to LOCK (0).
  1. Disconnect the steering angle sensor 5P connector.
  1. Turn the ignition switch to ON (II).
  1. Measure the voltage between body ground and steering angle sensor 5P connector No. 2, No. 3 and No. 4 terminals individually.
Is there 5 V or more?
YES -
Repair short to power in the wire between the LKAS control unit and the steering angle sensor.■
NO -
Go to Step 10 .
  1. Turn the ignition switch to LOCK (0).
  1. Disconnect the VSA modulator-control unit 47P connector and LKAS control unit 26P connector.
  1. Turn the ignition switch to ON (II).
  1. Check for continuity between body ground and steering angle sensor 5P connector No. 2, No. 3 and No. 4 terminals individually.
Is there continuity?
YES -
Repair short to body ground in the wire between the LKAS control unit and the steering angle sensor.■
NO -
Go to Step 14 .
  1. Turn the ignition switch to LOCK (0).
  1. Check for continuity between LKAS control unit 26P connector No. 18 terminal and steering angle sensor 5P connector No. 2 terminal.
Is there continuity?
YES -
Go to Step 16 .
NO -
Repair an open in the wire between the LKAS control unit and the steering angle sensor.■
  1. Check for continuity between LKAS control unit 26P connector No. 5 terminal and steering angle sensor 5P connector No. 4 terminal.
Is there continuity?
YES -
Go to Step 17 .
NO -
Repair an open in the wire between the LKAS control unit and the steering angle sensor.■
  1. Check for continuity between LKAS control unit 26P connector No. 6 terminal and steering angle sensor 5P connector No. 3 terminal.
Is there continuity?
YES -
Go to Step 18 .
NO -
Repair an open in the wire between the LKAS control unit and the steering angle sensor.■
Are any DTCs indicated?
YES -
Troubleshoot the VSA modulator-control unit DTC(s).■
NO -
Check for loose terminals in the LKAS control unit connector, and repair if necessary. If all connections are OK, replace the LKAS control unit. ■