4x4
j.rozco
03-13-2019, 01:57 AM
2000 Escalade service 4wd light comes on after a couple of minutes or sometimes right away. It has a new control switch.
Blue Bowtie
03-13-2019, 08:59 AM
The most effective thing to do is have the powertrain scanned for set or pending error codes. That will provide a hint as to what the PCM thinks is wrong and minimize the guesswork.
There are position sensors in the transfer case control (shifting) motor, as well as the TCCM module itself, and the control switch which you have already replaced. There is also a fair amount of wiring and connectors in the system, all of them getting close to 20 years old.
There are also speed sensors in the NPG transfer case, and they can get covered with magnetic particles due to normal wear of the clutch plates and friction steels. If it has not had the transfer case oil (Auto-Trak II oil) changed at 50-75,000 mile intervals, it may need to have the speed sensors removed, cleaned off, tested, and re-installed as part of draining and refilling the case.
There are position sensors in the transfer case control (shifting) motor, as well as the TCCM module itself, and the control switch which you have already replaced. There is also a fair amount of wiring and connectors in the system, all of them getting close to 20 years old.
There are also speed sensors in the NPG transfer case, and they can get covered with magnetic particles due to normal wear of the clutch plates and friction steels. If it has not had the transfer case oil (Auto-Trak II oil) changed at 50-75,000 mile intervals, it may need to have the speed sensors removed, cleaned off, tested, and re-installed as part of draining and refilling the case.
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