Monitor Description

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

• L4 switch indicated that the L4 transfer-case gears are engaged.
• Transfer-case shifter is in the "H" position.
• Transfer-case output shaft rpm is between 1,000 and 3,000 rpm.
• The specified time period has elapsed.

If all of the above conditions are detected, the ECM will conclude that there is a malfunction of the L4 switch, and illuminate the MIL and store the DTC.