LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2002 >> Astro Van Passenger, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 827 (Automatic Transmission - 4L60-E/4L65-E (Service & Replacement)) >> Diagnostic Information and Procedures >> Tow/Haul Switch/Indicator Always On or Inoperative >> Circuit Description

Circuit Description

WARNING: This page is about a different car, the 2003 GMC Safari and 2003 Chevrolet Astro. However, it is still accessible from the selected car via links, so may be relevant.

Tow/haul mode enables the operator to achieve enhanced shift performance when towing or hauling a load. When tow/haul mode is selected, the tow/haul switch input signal to the body control module (BCM) is momentarily toggled to zero volts. This signals the powertrain control module (PCM) to extend the length of time between upshifts and increase transmission line pressure. Cycling the tow/haul switch again disables tow/haul mode and returns the transmission to a normal shift pattern.