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EPS DTC Troubleshooting: 12-01

DTC 12-01:
 Low/High VBU Voltage (Regular Diagnosis)
  1. Turn the ignition switch to ON (II).
  1. Clear the DTC with the HDS.
  1. Turn the ignition switch to LOCK (0).
  1. Turn the ignition switch to ON (II).
  1. Check for DTCs with the HDS.
Is DTC 12-01 indicated?
YES -
Go to Step 6 .
NO -
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals.■
  1. Turn the ignition switch to LOCK (0).
  1. Check and note BATTERY voltage in the EPS DATA LIST with the HDS.
Is the battery OK?
YES -
Go to Step 8 .
NO -
  1. Check the No. 2 (60 A) fuse in the battery terminal fuse box.
Is the fuse OK?
YES -
Reinstall the No. 2 (60 A) fuse, then go to Step 17 .
NO -
Go to Step 9 .
  1. Disconnect the EPS control unit connector A (2P).
  1. Check for continuity between EPS control unit connector A (2P) terminal No. 2 and body ground.
Is there continuity?
YES -
Repair short to body ground in the wire between the EPS control unit and No. 2 (60 A) fuse in the battery terminal fuse box.■
NO -
Install a new No. 2 (60 A) fuse in the battery terminal fuse box, then go to Step 11 .
  1. Reconnect the EPS control unit connector C (16P).
  1. Turn the ignition switch to ON (II).
  1. Clear the DTC with the HDS.
  1. Turn the ignition switch to LOCK (0).
  1. Start the engine.
  1. Check for DTCs with the HDS.
Is DTC 12-01 indicated?
YES -
NO -
Troubleshooting is complete. If any other DTCs are indicated, go to the indicated DTC's troubleshooting.■
  1. Disconnect the EPS control unit connector A (2P).
  1. Turn the ignition switch to ON (II).

  1. Measure the voltage between EPS control unit connector A (2P) terminal No. 2 and body ground.
Is there battery voltage?
YES -
Check for loose terminals in the EPS control unit connectors and repair if necessary. If no poor connections are found, replace the EPS control unit.
NO -
Repair open in the wire between the No. 2 (60 A) fuse in the battery terminal fuse box and the EPS control unit.■