Inspection Procedure 3

INSPECTION PROCEDURE 3: When the Selector Lever is Moved to "N" Position, Auto-cruise Control System is not Cancelled [A/T].

























CIRCUIT OPERATION

- Battery positive voltage is applied to the transmission range switch (terminal 8) when the ignition switch is turned "ON."
- Battery positive voltage is applied to the PCM terminal 77 when the selector lever is in the "N" range. The PCM judges that the selector lever is in the "N" range when the battery positive voltage is applied.

COMMENT

The transmission range switch circuit is suspected.

TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THIS CASE:)

- Malfunction of the transmission range switch.
- Damaged harness or connector.
- Malfunction of the PCM.

DIAGNOSIS

Required Special Tools:

- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A

STEP 1. Using scan tool MB991958, check data list item 88: Neutral switch.





(1)
CAUTION:
To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

Connect scan tool MB991958 to the data link connector. (Refer to Reading and Clearing Diagnostic Trouble Codes).
(2)Turn the ignition switch to the "ON" position.
(3)Set scan tool MB991958 to data reading mode for auto-cruise control system. (Refer to Scan Tool Testing and Procedures).

- Item 88, Neutral switch.
- When selector lever is at the "N" position, the display on scan tool MB991958 should be "ON".
- When selector lever is other than "N" position, the display on scan tool MB991958 should be "OFF".
(4)Turn the ignition switch to the "LOCK" (OFF) position.
(5)Disconnect scan tool MB991958.

Q. Is the switch operating properly?

YES Go to Step 3.

NO Go to Step 2.

STEP 2. Using scan tool MB991958, read the A/T system diagnostic trouble code.





(1)
CAUTION:
To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

Connect scan tool MB991958 to the data link connector. (Refer to Reading and Clearing Diagnostic Trouble Codes).
(2)Turn the ignition switch to the "ON" position.
(3)Check for A/T system diagnostic trouble code. Reading and Clearing Diagnostic Trouble Codes).
(4)Turn the ignition switch to the "LOCK" (OFF) position.
(5)Disconnect scan tool MB991958.

Q. Is any DTC P1770 or P1771 set?

YES P1770, DTC P1771: Transmission Range Switch System (Short Circuit) P1771. Then go to Step 4.

NO Go to Step 3.

STEP 3. Check the symptoms.

Q. When the selector lever is moved to "N" position, auto-cruise control system is cancelled?

YES It can be assumed that this malfunction is intermittent. How to Cope With Intermittent Malfunctions).
NO Replace the PCM. Immobilizer System). Then go to Step 4.
STEP 4. Check the symptoms.

Q. When the selector lever is moved to "N" position, auto-cruise control system is cancelled?

YES The procedure is complete.
NO Return to Step 1.