Cold and old: The Montero Sport 4x4

March 2, 2015

With the cold weather hitting many areas of the country nearing an end, spring time fever outweighs a cold headache anytime. Some things are designed to work well in the cold and some are not, especially when they get old. 1997 to 2001 Mitsubishi Montero Sport 4x4 models is one such example. The vehicle comes into the shop with a complaint of poor engine performance, no 3-4 shift and the transfer case is stuck in two wheel drive.

There are three switches mounted on the transfer case, a Low, 2-4 and High-Low detection switches (figure 1).

Located on the main transfer case body, the 2-4 Detection Switch activates when the transfer case is shifted from 2WD to 4WD. It engages the front axle by signaling the 4WD ECU. If this switch does not operate properly, the 4WD lamp may stay on while in 2WD mode, or the front axle may not engage. The 2-4 Detection Switch has a two wire pigtail lead going to a BLACK connector.

Located in the rear area of the transfer case, the High-Low Detection Switch (P/N MB886426) turns OFF the 4WD indicator lamp when the transmission 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 and 4L). The High-Low Detection Switch has a two wire pigtail lead going a GRAY connector.

Located near the High-Low Detection Switch, the Low Detection Switch activates when the transfer case is shifted to 4LOW. It signals the PCM to initiate “Fuel Cut” in 4LOW mode and prevents the transmission from shifting into 4th gear. The Low detection Switch has a one wire pigtail lead going a WHITE connector. Figure 1 is a view of all three of these switches’ bracket mounted connectors.

This detection switch is only found with vehicles using automatic transmissions.

With these vehicles getting older, along with the cold weather combined with a lack of use, these switches are prone to getting stuck.

It is the malfunction of the Low Detection Switch or wiring that causes a complaint of poor engine performance, no 3-4 shift and the transfer case is stuck in two wheel. In some cases if the switches are stuck due to corrosions or lack of use, all one may need to do is work the transfer case shifter back and forth. This may un-stick the switch and the vehicle will resume normal operation. Otherwise new switches will need to be purchased.

2-4 Detection Switch part number - MB811554

High-Low Detection Switch part number - MB886426

Low Detection Switch part number - MR246221

2001 to 2001 Montero’s with the Active Transfer Case (figure 2) utilizes 5 detection switches (figure 3) which are susceptible to water/moisture entry corroding the terminals. This may produce code 33 accompanied with a flashing 4WD indicator lamp. These switches were updated.