randy2016

Hi all,


My speedometer stopped working the other day (I restarted car and then it seem to work ok; it was very muggy that day). The next few days it worked ok. Yesterday on my way to work, it seem to be giving me a high reading; giving me 70mph, I would say I was going between 55-60. Now it is not working at all; all the other needles work fine. The odometer seems to be working, but it seems like its going slightly fast. I checked under the car and the sensor wire seems like there is a good amount of tension on it. Is it possible that the sensor could be bad, even tho I am getting data to the odometer? I have heard that there are 2 sensors for the cluster; maybe one is working and other is intermittent. One other thing, the day before this happened, I ran over a branch in the road (I could hear the branch hit the bottom of the car) I hope that this is the issue; I don't want to start screwing with the cluster. I did find a place that will rebuild for $175.00 with a lifetime warranty, but it will be a pain to remove. Thanks

LScowboyLS

intermittent not working speedometer is usually either:

1. stickiness at the rest point from old original lubricant
2. failing cluster capacitors
3. failing ECU capacitors

mine was due to #3

randy2016

Another thing, I also get what I could best describe as a delayed engagement of the 2nd gear sometimes when I first start out. I will get upto about 2800rpm before I get into 2nd gear. I have herd that this is common and I have also seen that this could be indicative of a bad speed sensor.

randy2016

LScowboy, was you cluster still backlit, with the bad cap? Thanks for the reply

LScowboyLS

yes, my cluster lighting has always been fine, even with the failing ECU capacitors

LScowboyLS

could be a bad speed sensor, or another sign of failing ECU caps, keep in mind that in the LS400, there is no transmission ECU, all transmission control is done by the main ECU.

randy2016

Ok, thanks. Is the ECU the unit that is right under the glove box, on the side wall? Maybe I will take that too, they can check the caps on that. Were you getting any codes when your ecu was bad? I am not.

randy2016

I am taking the car tomorrow to my mechanic for him to test speed sensor. Is there a way for him to test the ecu, with scan tool (if it is the ecu), if its giving a null value to the cluster?

LScowboyLS

there is a way to test the ECU. but it is going to be beyond the scope of your mechanic's capability, as is repairing it - you need an electrical engineer for this

randy2016

Ok, I have a place that is not too far from me (BBA-Reman) that can fix the ECU, and cluster if need be. $175 for them to rebuild cluster with warranty; I consider that reasonable. Do you know if the cluster has a different signal wire for the odometer vs the speedometer? Do you know where the speed sensor is located on the transmission? Thanks

randy2016

LScowboy; I took my car to the shop today, they told me that they could not see anything (no codes), he did tell me that his computer was talking to my computer ok with no issues. When you had the bad caps in your ecu, did you have any other issues? Would it not talk to scan tool? I have to take my car to a transmission shop; he told me that they will have better equipment to analyze the transmission speed sensors. If need be, I will have cluster rebuilt only after I clear everything else.

KeyKeeper

The speed sensor is a hall effect sensor that can be checked with a reg digital multimeter.

LScowboyLS

read post #1

galelee510

The speedometer on my ls400 would sometimes not work, then would work, etc. Now it has stopped working. Any suggestions?

RA40

iTrader: (6)

galelee510, what year LS? The 1-LS FAQ has discussion on the gauge cluster