2006 Buick Rainier - Mountain of problems

buick

#1

After replacing a weak battery, truck started several weird possessed problems. 1- would shut down for no reason and go into an electrical lockout mode where nothing would work.
2- would simply not attempt to start and then miraculously start as if nothing were wrong. Did have to replace a defective battery cable bolt on the positive cable.
Now the car is sitting, won’t do anything. No code recorded in memory when checked with code reader.
Battery checks fully charged.


#2

Does it turn over? Do the headlights turn on?


#3

Given that you found a problem with the battery connection, I’d remove all 4 connections (two cables, two ends) and clean the mating surfaces.

“won’t do anything” ? can you elaborate on this? what exactly happens when you try to start it?


#4

You replaced the positive battery terminal bolt.

Did you also check the positive battery terminal for corrosion?

Tester


#5

Do you have an after market remote start?


#6

What happens when I attempt to start the car is as previously stated, nothing. All the warning lights appear, time out, but no cranking of starter. I had a similar problem with this auto years ago and had to replace the ignition switch. Ordered a replacement from Rock Auto. Hoping this will resolve the problem.


#7

Yes, lights come on when ignition is turned on, warning lights come on and time out, but no starter motor. Have ordered replacement ignition switch.


#8

Hope that works. If it doesn’t, you need to make sure the cable between positive battery and starter is clean on both ends, and is not damaged. Same for negative cable both ends. These are free fixes. If cables are good and clean, check starter. If starter is good the problem is in the primary circuit. Ignition switch, wiring relay solenoid. You bought an ignition switch not knowing if that was the problem. That can be an expensive habit. If ignition switch doesn’t do the trick, I would make SURE cablesare good. If they are, do what George San Jose 1 says. If that doesn’t work, take it to a shop, this is an easy diagnosis if a tech had the car in front of him.


#9

When the key is in start both terminals of the starter motor should be at least 10.5 volts, when measured terminal to starter case. If they are both above 10.5 volts and it doesn’t crank, replace the starter motor. If one or both isn’t, work from the starter toward the battery to find why not. Battery, battery connections, neutral safety switch, ignition switch, and security modules are common reasons for ‘fails to crank’.


#10

Have connected remote starter switch, working fine. Finally got error code to reveal two issues. 1) TAC and 2) Ignition switch. Working on both.


#11

Connected remote starter switch, working fine. Finally got 2 error codes to appear: 1) TAC and 2) Ignition switch. Working on both.


#12

Connected remote starter switch, working fine. Finally received 2 error codes: 1) TAC and 2) Ignition switch. Working on both.


#13

Found this service bulletin for the TAC.