Inspection Procedure 22: Power Steering Fluid Pressure Switch System




OPERATION



  • It is detected whether a load is applied on the power steering fluid pump by steering or not, and the signal is inputted to the engine-ECU. When the power steering fluid pressure switch "ON" signal (a large load on the power steering fluid pump) is inputted, the engine-ECU provides the idle-up control.

PROBABLE CAUSES



  • Failed power steering fluid pressure switch
  • Damaged harness (Open or short circuit between power steering fluid pressure switch and engine-ECU)
  • Damaged connector (Engine-ECU connector, power steering fluid pressure switch connector)
  • Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. Connector check: A-134 power steering fluid pressure switch connector

Q. Is the check result normal?

Go to Step 2 .

Repair or replace.

STEP 2. Check at A-134 power steering fluid pressure switch connector.


  • Disconnect connector, and measure at harness side.
  • Engine: idling
  • Short-circuit terminal No. 1 to earth.
OK: The engine speed rises (idles up)

Q. Is the check result normal?

Go to Step 3 .

Go to Step 4 .

STEP 3. Check power steering fluid pressure switch itself.

  • Check Power steering fluid pressure switch itself (Refer to GROUP 37 - On-vehicle Service - Power steering fluid pressure switch check ).

Q. Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).
Replace the Power steering fluid pressure switch.

STEP 4. Connector check: C-103 engine-ECU connector

Q. Is the check result normal?

Go to Step 5 .

Repair or replace.

STEP 5. check harness between C-103 (terminal No. 96) engine-ECU connector and A-134 (terminal No. 1) power steering fluid pressure switch connector.


note Before checking harness, check intermediate connector A-27 and A-115, and repair if necessary.

Q. Is the check result normal?

Replace the engine-ECU. When the engine-ECU is replaced, write the chassis number (Refer to GROUP 00 - How to Perform Chassis Number Writing ). After replacing the engine-ECU, register the injector identification code and learn fuel injection (Refer to GROUP 00 - Precautions Before Service - What The Common Rail Engine Learns ).

Repair the harness wire.