: Left Side Directional Single Flashing Rapidly After 3 Normal Flashes



worahm
04-01-13, 03:43 PM
Can anyone explain why the left side directional single on my DTS Cadillac flashes rapidly after 3 normal flashes? The right side flashes normally. All bulbs are lit.
Bill

Stepside
04-05-13, 08:10 PM
Evidently, :coffee:the impedance is changing after the 3rd flash, which would leave me to think
that it is possible, that a fault exist with the filament in the light or the relay is at fault.
The lights resistance aka impedance may not be compatible for the circuit its installed in.
:vulcan:
What year is your Cadillac.

worahm
04-05-13, 09:02 PM
Evidently, :coffee:the impedance is changing after the 3rd flash, which would leave me to think
that it is possible, that a fault exist with the filament in the light or the relay is at fault.
The lights resistance aka impedance may not be compatible for the circuit its installed in.
:vulcan:
What year is your Cadillac.

It is a 2008.

I am working with limited information but as best as I can determine, the circuit is designed to flash 3 times for a lane change when the directional signal lever is momentarily moved but not locked in place. I suspect the 3 flashes occur because the lever has to go through the lane change position to get to the locked on position. So, I reason, the 3 flashes are the result of the initial lane change position. When the lever is locked on, a second circuit is used to cause the directional lights to continue flashing. I am thinking the fault may be in that second circuit. If the second circuit is OK, the lights will continue to flash (after the 3 lane change flashes are completed) at a normal speed.

The relay appears to be located in the driver side door. Can anyone tell me where the circuit board(s) are located?

Bill

Stepside
04-06-13, 09:34 AM
According to the Service Manual:
If the left turn signal lamps & indicators illuminate but flash in a rapid manner, Refer to Tail Lamp Outage Detection Malfunction.

Do the front, rear, And mirror lamp blink?
Double check the left tail lamps for proper illuminationand blinking, even when applying brake.

Could be as simple as fixing a short to ground, a bulb replacement/tail light assembly.

Hopefully, the problem is not the instrument panel cluster IPC; or the body control module BCM.

worahm
04-06-13, 12:49 PM
Stepside. Thanks for the very prompt reply.

All the lights, front and back and RR mirrors work as they should except for the left side directional signal which flashes at a normal rate three times and flashes more rapidly when I lock the switch on.

Yesterday, I had a local Chevrolet dealer check for shorts in the system and the BCM. After 8 hours, they gave up and told me that I had to replace the left side tail light assembly and the BCM. They refused to replace the BCM alone. They mentioned something about once they reprogramed the new BCM and the system did not work the BCM was not reprogramable.

I am not certain how long the Tail Lamp Outage Detection Malfunction article is and I understand it is asking a lot but if it is not too much trouble could you please send me a copy of that section? My email address is worahm@comcast.net

I am trying to find digitized 2008 Cadillac Service Manuals to down load. Can you recommend a good source for those manuals? Bill

Stepside
04-06-13, 08:04 PM
SERVICE MANUAL: http://www.cadillacforums.com/forums/cadillac-dts-forum-2006-through-2012/279758-2006-2008-dts-service-manual-12-a.html

Which is: http://www.ebay.com/itm/150740650161?item=150740650161&viewitem=&sspagename=ADME:L:OC:US:3160&vxp=mtr
thanks to billdaman for posting this for us. on Jan 19, 2013

:hmm:hmmm, well, :coffee:I hope it does not turn out to be the 'turn signal multifunction switch' :suspense: after they do the BCM & 'tail light assembly'.

I tried to copy and paste that section earlier . . but, had no luck. Go to the web site above - download - read tonight.:thumbsup: $13.00

Good luck :vulcan:

danog
04-06-13, 11:46 PM
Why don’t you take thr right tail light out and plug it into the left rear and see if the problem goes away.
About the BCM we update the softwear all the time by reprograming them. The tech 2 should tell them if it’s in the tail light or not by a code it sets in the BCM.

worahm
04-07-13, 02:27 PM
Does anyone know what size flash drive I need to download the Cadillac PDF file being sold on Ebay? I have contacted the seller but as of now, I have not hear anything. Bill

ral1960
04-07-13, 02:52 PM
I'd consider it an endearing quirk and stop spending money chasing it, if it passes state inspection and isn't about to turn the car into a raging fireball.

Stepside
04-07-13, 09:51 PM
The size of the file is: :coffee:144MB when unzipped using WinZip & Adobe Reader XI :wisdom: