'99 Service AWD light and clicking

[bravada21]

I'm new to the site here and need some info. I have a 99 bravada (140K miles) and have recently noticed the Service AWD light coming on when I start up the vehicle. There is also a series of 4-5 clicks (sounds like a relay) coming from the glove box or passenger floor area only upon startup and only when the AWD light comes on. The light will stay on until I shut off the vehicle. Other times, the AWD light and clicking sound will not occur (they seem to work together). The AWD system seems to be working fine though.

I've seen some posts on here about the AWD light and the clicking sound, but not together in the same thread. But maybe I haven't found it yet. If anyone knows about this or has had the same problem and found the culprit, please post back. Thanks in advance for your help.

[Chris Stewart]

Whew, I'm missing too many pitches.
I don't know if the AWD can set trouble codes.

[FantasticChadwick]

Originally Posted by bravada21

I'm new to the site here and need some info. I have a 99 bravada (140K miles) and have recently noticed the Service AWD light coming on when I start up the vehicle. There is also a series of 4-5 clicks (sounds like a relay) coming from the glove box or passenger floor area only upon startup and only when the AWD light comes on. The light will stay on until I shut off the vehicle. Other times, the AWD light and clicking sound will not occur (they seem to work together). The AWD system seems to be working fine though.

I've seen some posts on here about the AWD light and the clicking sound, but not together in the same thread. But maybe I haven't found it yet. If anyone knows about this or has had the same problem and found the culprit, please post back. Thanks in advance for your help.

Welcome to my Bravada problems.

The 4-wheel drive is really the only disappointment my 2000 Bravada has offered me. It has gone out twice, both times it has displayed the symptoms you described. The first time it was under warranty and I took it in to get fixed. Fortunately the warranty company footed the $1000 bill. The second time, I ordered an aftermarket "transfercase motor" and installed it myself. The "service AWD" light and the clicking went away, but the 4-wheel drive doesn't engage.

When I installed the part it clearly stated on it that it was set up to be installed when the 4-wheel drive was engaged. Since the part to engage the 4-wheel drive was in my hand and not on my vehicle I used a pry-bar to reposition the little thing on the transfercase motor that turns to engage the 4 wheel drive. I got it to fit onto the vehicle, but apparently they weren't kidding about the vehicle having to be in AWD.

If you care, I bought the part that I apparently installed incorrectly from www.rockauto.com. If anyone has any informationa bout getting the vehicle into AWD when it's broken please let me know. Thanks.

Chadwick

[atfdmike]

At the risk of offending SOMEONE out there...............


The Transfer Case Diagnostic System Check must always be the starting point of any system diagnosis. The Transfer Case Diagnostic System Check verifies proper SERVICE indicator (AWD/4WD) lamp operation and checks for ATC Diagnostic Trouble Codes (DTC) using the scan tool. The following describes the difference between current and history DTCs:

• Current DTCs - Malfunctions that are presently being detected. Random Access Memory (RAM) stores the current DTCs. Turning the ignition switch to the OFF position resets current DTCs and logs the codes in history. The presence of a current DTC will cause the transfer case shift control module to turn ON the SERVICE indicator (AWD/4WD) lamp.
• History DTCs - All malfunctions detected since last clearing of history memory. Electrically erasable programmable read only memory (EEPROM) stores the history DTCs. A scan tool clear codes command will erase history DTCs.

[FantasticChadwick]

Originally Posted by atfdmike

At the risk of offending SOMEONE out there...............


The Transfer Case Diagnostic System Check must always be the starting point of any system diagnosis. The Transfer Case Diagnostic System Check verifies proper SERVICE indicator (AWD/4WD) lamp operation and checks for ATC Diagnostic Trouble Codes (DTC) using the scan tool. The following describes the difference between current and history DTCs:

• Current DTCs - Malfunctions that are presently being detected. Random Access Memory (RAM) stores the current DTCs. Turning the ignition switch to the OFF position resets current DTCs and logs the codes in history. The presence of a current DTC will cause the transfer case shift control module to turn ON the SERVICE indicator (AWD/4WD) lamp.
• History DTCs - All malfunctions detected since last clearing of history memory. Electrically erasable programmable read only memory (EEPROM) stores the history DTCs. A scan tool clear codes command will erase history DTCs.

Do I need to erase the history to get it shift after replacing the transfer case motor? Or is it your opinion I screwed up installing the part or that there may be another problem even though the light is no longer coming on?

[atfdmike]

Hi, It seems from your previous post that there is some question as to whether or not you properly engaged the shift mechanism. I would start there. Once you are sure it is right, then your Bravada should drive normally, and no, you do not have to erase the codes for it to be OK to drive. After a certain number of ignition cycles without seeing the problem, the computer will erase any related code. It is usually a good idea to erase it though, as it gives you a clean slate to start over and see if the same problem is reoccuring. One owners opinion.