Monitor Description

The ECM monitors the transfer L4 position switch to determine when the transfer-case L4 gear is engaged. If the transfer-case L4 gears remain engaged under all of the following conditions, the ECM will conclude that there is a malfunction of the transfer L4 position switch:

• The transfer L4 position switch indicates that the L4 transfer-case gears are engaged.
• Transfer-case shift lever is in the "H" position.
• Transfer-case output shaft rpm is between 750 and 3,000 rpm.
• The specified time period has elapsed.

  Then the ECM will illuminate the MIL and store the DTC.