Transfer Case Switches - Operation/Configuration
Bulletin No: TSB-01-23-011DATE: October, 2001
MODEL:
1997-2001 Montero
Sport 4WD
SUBJECT:
TRANSFER CASE DETECTION SWITCHES - CONFIGURATION & OPERATION CLARIFICATION
PURPOSE
This bulletin contains information to clarify configuration and operation of the three detection switches on the transfer case.
AFFECTED VEHICLES
1997-2001 Montero Sport 4WD equipped with automatic transmission
NOTE:
This bulletin addresses vehicles with automatic transmission, however the 2-4WD Detection Switch and the High-Low Detection Switch are also used in the 1997-99 Montero Sport vehicles equipped with the 5-speed manual transmission. Both of these switches operate in the same manner in both the A/T and M/T equipped vehicles. The LOW Detection switch is used ONLY in the A/T equipped vehicles.
SERVICE INFORMATION
Configuration, Location, and Operation
There are three transfer case detection switches. The following shows the location of these switches and summarizes each switch's purpose and operation. The following clarifies some information in the service manuals.
^ 2-4WD Detection Switch
The 2-4WD Detection Switch (MB811554) is located in the main transfer case body, and has a black connector. This switch activates when the transfer case is shifted from 2WD to 4WD. It actuates the freewheel front axle via the 4WD ECU. If this switch does not operate properly, the 4WD light may stay on while in 2WD mode, or the front axle may not engage in 4WD.
^ High-Low Detection Switch
The high-low detection switch (P/N MB886426) is located in the rear area of the transfer case and has a gray connector. This switch turns OFF the 4WD light when the A/T is shifted into 'N' (neutral) and the transfer case is shifted between 4H and 4L. Its purpose is to detect the neutral position of the transfer case (the position between 4H & 4L).
^ Low Detection Switch (A/T equipped vehicles ONLY)
The low detection switch (MR246221) is located near the H-L detection switch and is on a rear-facing boss on the transfer case. This switch activates when the transfer case is shifted to 4L. It signals the PCM to operate fuel cut in 4L mode and to prevent the transmission from shifting into 4th gear. The low detection switch has a single-wire white connector.
Troubleshooting
If you suspect a problem, but find no switch electrical failure, the switch may merely be stuck from infrequent use. For first time complaints, try shifting into and out of 4WD while warming the transfer case. This may free the switch(es) and correct the situation. A shorted Low Detection switch can cause fuel cut to incorrectly activate then the vehicle is in 2WD. Recommend to customers that occasionally shifting in and out of 4WD can reduce the possibility that a switch may stick and cause on of the above mentioned switch-related conditions.
PARTS INFORMATION
WARRANTY INFORMATION
This bulletin is for information only, not warranty authorization. Normal warranty procedures apply.