Qusetion by: Keith Booysen Answer by: Arnold VenterMy ’02 Colt Clubcab 2.8 TDI with 110 000 km has just developed a strange problem: the green 4WD light refuses to turn off when 2WD is selected. I’ve tried everything – bringing the vehicle to a complete stop, engaging / disengaging low-range, reversing… everything, but the light stays on. What could be the cause of this problem?
What’s more, when the vehicle does finally go into 2WD it takes a long time to re-engage 4WD, especially if I’ve driven the vehicle long distances – as I found after getting stuck in a mud hole in Chobe.
Keith Booysen
THE EXPERT’S OPINION:
The 4WD system in your Mitsubishi operates as follows: upon starting the vehicle, an engine vacuum keeps the 4WD system deactivated and held in the 2WD position within the transfer case (TC). When 4-high is selected various TC switches are activated; one triggers the instrument cluster’s green 4×4 indication light, and the other sends a signal to a vacuum-inhibitor switch which alters a vacuum pod on the front diff. This vacuum pod allows the prop shaft to engage the diff and therefore 4WD – this can be done on the fly as the front side shafts are engaged permanently. Once the front diff is rotating, another switch – on the diff itself – informs the 4×4 engage ECU that the prop shaft and diff are rotating in unison.
In your case there are two scenarios that could be at play. There’s either a vacuum loss in 2WD – check the vacuum unit under the air box – or the front diff switch is faulty, causing the vehicle to remain in 4WD even when 2WD is selected. We’ve often seen the wiring loom ripped from the switch housing, causing this problem. Your problem isn’t an isolated incident – we often receive this query from other Colt owners.
Arnold Venter
CRD (4×4 fitment & repairs)
(011) 907 0580 / arnold@crd.co.za
