Inspection Procedure 3

Park/neutral Position Switch Circuit:

CIRCUIT OPERATION
This circuit transmits the "N" or "P" position signal of the park/neutral position switch to the auto-cruise control-ECU.
When the park/neutral position switch is at the "N" or "P" position, auto-cruise control-ECU terminal number 13 will receives 0 volt.

TECHNICAL DESCRIPTION (COMMENT)
The cause is probably an open-circuit in the output signal circuit in "N" range.

TROUBLESHOOTING HINTS
- Malfunction of the park/neutral position switch.
- Damaged harness or connector.
- Malfunction of the auto-cruise control-ECU.

DIAGNOSIS

Required Special Tool:
- MB991223: Harness Set




STEP 1.Check the output circuit voltage at park/neutral position switch connector B-01 by backprobing.
1. Do not disconnect park/neutral position switch connector B-01.
2. Turn the ignition switch to "ON" position.
3. Measure the voltage between terminal 10 and ground by backprobing.
- Voltage should be battery positive voltage.
(When select lever is in a position other than "N" range.)
- Voltage should be 0.5 volts or less.
(When select lever is in "N" range.)

4. Turn the ignition switch to "LOCK" (OFF) position.

Q: Is the voltage within specifications?

YES: Check that the malfunction is eliminated.
If the malfunction is eliminated, replace the auto-cruise control-ECU.
Then check that the malfunction is eliminated.

NO: Go to Step 2.







STEP 2.park/neutral position switch connector B-01.

Q: Is the connector damaged?

YES: Repair or replace connector.
Refer to Harness Connector Inspection.
Then check that the malfunction is eliminated.

NO: Go to Step 3.

STEP 3.Check the circuit at the park/neutral position switch.
1. Disconnect the park/neutral position switch connector B-01.







2. Measure the continuity park/neutral position switch connector terminals.

Q: Is the continuity meet the table above?

YES: Go to Step 4.

NO: Replace the park/neutral position switch.
Refer to Transmission.
Then check that the malfunction is eliminated.




STEP 4.Check the output circuit voltage at auto-cruise control-ECU connector C-35 by backprobing.
1. Do not disconnect auto-cruise control-ECU connector C-35.
2. Turn the ignition switch to "ON" position.
3. Measure the voltage between terminal 13 and ground by backprobing.
- Voltage should be battery positive voltage.
(When select lever is in a position other than "N" range.)
- Voltage should be 0.5 volts or less.
(When select lever is in "N" range.)

4. Turn the ignition switch to "LOCK" (OFF) position.

Q: Is the voltage within specifications?

YES: Check that the malfunction is eliminated.
If the malfunction is eliminated, replace the auto-cruise control-ECU.
Then check that the malfunction is eliminated.

NO: Go to Step 5.




STEP 5.Check auto-cruise control-ECU connector C-35.

Q: Is the connector damaged?

YES: Repair or replace connector.
Refer to Harness Connector Inspection.
Then check that the malfunction is eliminated.

NO: Go to Step 6.




STEP 6.Check intermediate connector C-30.

Q: Is the connector damaged?

YES: Repair or replace connector.
Refer to Harness Connector Inspection.
Then check that the malfunction is eliminated.

NO: Go to Step 7.










STEP 7.Check the harness wire between park/neutral position switch connector B-01 and auto-cruise control-ECU connector C-35.

Q: Is any harness wire between park/neutral position switch connector B-01 and auto-cruise control-ECU connector C-35 damaged?

YES: Repair the harness wire and then check that the malfunction is eliminated.

NO: Check that the malfunction is eliminated.
If the malfunction is eliminated, replace the auto-cruise control-ECU.
Then check that the malfunction is eliminated.