Code No. C1436: F/W engage SW
OPERATION
The freewheel engage switch is turned ON when the freewheel engage solenoid valve is activated and the condition is shifted to the 4WD condition. The power supply voltage is imposed to the freewheel engage switch from the transfer-ECU, and when the freewheel engage switch is turned ON, the power supply voltage from the transfer-ECU is earthed.
DIAGNOSIS CODE SET CONDITIONS
When the energising condition to the freewheel engage solenoid valve and the condition of freewheel engage switch do not agree, code No.C1436 is set as the open circuit or the short circuit on the freewheel engage switch system.
PROBABLE CAUSES
- Malfunction of the freewheel engage switch
- Damaged harness wires and connectors
- Malfunction of the transfer-ECU
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STEP 1. M.U.T.-III diagnosis code
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Check if diagnosis code is set in the transfer-ECU.
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Q.
Is the diagnosis code set?
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 Troubleshoot the transfer-ECU. Refer to  .
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 Go to Step 2.
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STEP 2. M.U.T.-III data list
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Use the transfer-ECU service data to check the signals related to the operation of freewheel engage switch.
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- Turn the drive mode-selector to the "4H" position.
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Item No.
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Item name
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Normal condition
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44
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F/W position switch
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Engage
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- Turn the drive mode-selector to the "2H" position.
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Item No.
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Item name
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Normal condition
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44
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F/W position switch
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Disengage
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OK: Normal condition is displayed.
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Q.
Is the check result normal?
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The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
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Go to Step 3.
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STEP 3. Check the freewheel engage switch.
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Refer to GROUP 26 - Inspection .
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Q.
Is the check result normal?
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Go to Step 4.
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Replace the freewheel engage switch (Refer to GROUP 26 - Differential carrier and free wheeling clutch ).
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STEP 4. Resistance measurement at the freewheel engage switch connector (earth terminal).
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(1)Disconnect the connector, and measure at the wiring harness side.
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(2)Measure the resistance between the freewheel engage switch connector (earth terminal) and body earth.
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(3)OK: Continuity exists (2 Ω or less)
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Q.
Is the check result normal?
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Go to Step 6.
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Go to Step 5.
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STEP 5. Check of open circuit in earth line between the freewheel engage switch connector and body earth.
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Q.
Is the check result normal?
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The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
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Repair the connector(s) or wiring harness.
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STEP 6. Check of short to power supply, short to earth, and open circuit in F/W line between transfer-ECU and freewheel engage switch connector.
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Q.
Is the check result normal?
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Go to Step 7.
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Repair the connector(s) or wiring harness.
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STEP 7. Retest the system
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Check that the freewheel engage switch functions work normally.
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Q.
Is the check result normal?
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The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
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Replace the transfer-ECU (Refer to ).
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