bick333

keep getting message to shift into reverse after I have already done so. Read several post for this problem. checked both switches on transmisson and reversed plugs to see if problem would go away. ( Logical that both switches would not go bad at same time.) No fix. replaced as found. Pulled battery after overnight went dead. 3 year old battery recharged, check ok at 12.6 volts. replaced in car and no starter action at all, as if battery low. voltage to run everything, reindexed windows, thought shift into reverse message was gone, then came back. Something seems out of sync with electronics, however I do not know what to do next. Disconnected Negative post to prevent battery from going dead again as car definitely not shutting power down. I would appreciate forum help.

bick333

still trying to solve. read DIC ands had 11.9 volts. charged for 15 minutes with jumper cables , read DIC at 12.9 volts! Tried to start. Still no response from starter. no clicking, no nothing, Still messaging shift into reverse. Disconnectred battery to keep from draining again. took positive post off first this time. then Negative. If bad battery, would it not start with jumper connected? thanks

schpenxel

Reverse switch on transmission?

Do reverse lights come on when shifter is in reverse position?

bick333

YES - Still believe computer is " out of sequence" however no knowledge of what I can do to correct. Several disconnects of battery. dash working fine - When engage Green Start button, seems to drain battery, however no clicking, no solenoid action and of course no starter action.

schizcat

Did you try a new battery? Sometimes charging them and then putting them back into these things wont set things straight....ask me how I know.

bick333

That may be next attempt to make it work correctly.
Electrical troubleshooting tough on new cars. Will double check all connections tonight. I would have thought Jumping with cables and already having 12 volts in the battery would have proved that point, however not sure if bad battery would prevent getting enough AMPs to turn starter.
Thanks for the input.

schizcat

I went through this a few years ago. Battery was bad, was jumped and still had issues. Charged battery and showed 12.9 and was still flaky. You are right, the electrical gremlins are hard to troubleshoot. Good look though.

Medicdiver

Just because you have 12 volts doesn't mean you have amperage. I can connect 8 AA battery's and get 12 volts, but it isn't going to start my car. Batteries in these cars are finicky. I had same issue in my 2005 Mn6 a few years ago and it was a blown fuse to the starter. Fuse should be in under hood fuse box, one of the larger ones. Check that. These cars aren't that hard to figure out compared to some.

Durien512

Could be a bad battery for sure .... saw this happen on my buddy's car

extrapilot

Have the battery "load" tested, most parts stores will do this for free.
Having voltage means nothing if the battery can not supply the amperage.
Next double check the starter solenoid on top of the starter, make sure that the connections are good and that the plastic bakelite at the connection stud is not broken.

bick333

Today replaced the battery with new one.
No help. green light, but nothing happens when push. operated clutch several times to see if that switch is acting up. no help. Wiring all tight to starter and on new battery. Still asking to "shift into reverse" even though I have in reverse when exiting the car. noticed today "check engine light" is on steady. Do not think it was on earlier in the problem. do not own OBD II tool. About ready to give up with DIY and have dealer pickup.
Any other suggestions?
thanks all for your suggestions.
bick

bick333

relooked at the starter wiring connections, smaller wire on middle terminal is really tight against the dip stick tube. looks like it could be damaged, from friction with the tube?. maybe remove tomorrow to see if frayed wire. Looks like factory install as I have never replaced the starter, plastic connector is green in color, . connections tight. new battery did load test and at 711. still feel some computer is out of sync!

Medicdiver

If you feel computer is out of Synch, reset it. Remove battery from vehicle, then attach positive wire, and negative wire together for about :30 seconds. This will discharge all capacitors in the system, and essentially reboot the system. Just removing the battery doesn't do it as the capacitors can hold power to the ECM for over an hour. It will do no damage doing this as long as the battery is disconnected. It will however reset clock, radio presets, memory seat presets, HID presets.

You stated earlier your Check engine light is on, do you have anyway to read the codes? That might give us something to go off of. Where are you located? Maybe someone here can come read a code quick for you.

Lastly, get a volt/ohm meter and check power to the starter solenoid when cranking (pushing start button.) That will tell you if starter is getting power and the starter is dead, or you have another issue.

If your in Northern Illinois I would be happy to help.

bick333

Friday I did the following, in no perticular order.
pulled relay 38, reinstalled
Pulled crank relay 43 , reinstalled,
Pulled fuse 10, reinstalld
Jumpered both switches on MN6
top switch is BU lights, so bottom switch shuts down electrical. Car starteds, removed jumoers, replugged leads onto switches. Shutdown. No shift to reverse light!
engine light off.
Today when shut down "shift to reverse back on. reproved top switch on transmission is BU lights. it works. Plugged other lead into switch that is working and BU lights into bottoem switch. BU lights no work so bottom switch is bad. However still have the shift into reverse with lead plugged into the working switch. Does not make sense. Disconnecterd Negative ground from battery to prevent another dead battery. I will try the Positive to negative connection to see what that does tomorrow. Will ask if anyone has reader to borrow.

Dano523

Top switch is Back up lights, so power in and when pressed by trans, sends power to the coil side of the back up lights relay.

Bottom switch is used for in reverse when pressed in by trans, so power in, then to BCM to send signal that trans in reverse when the detent is pushed in.

If you jump out the connector on the top switch connector, BU lights should come on.


If you jump out the lower switch connectors, then BCM sees trans in reverse to allow you to shut the car off and put it into sleep mode.

If jumping the switch connectors out does not produce the desired results, you have a problem in the wiring past the switch.

As for the switches, put the car into reverse and run a continuity check through the switch pins. If you get back no resistance, then the switch has a problem.

The switches are just contact switches via the plungers on them, so sometimes the problem is just a bad contact in the switch, while other times its the trans linkage that is not pushing the plunger all the way in isntead. I bring this up, since if the switches are not reading continuity through them with the trans in reverse, then pull the switches out of the trans, and check them again while you are pushing the plungers in by hand instead.

If it turns out that the switch test fine out of the trans, take a look in the switch channels in the trans with a flash light as you are shifting in and out of reverse for worn spots on the linkage that is not allowing the switch detentes to be pushed in far enough instead.

I bring this up, since sometimes the linkage wear is not so great to warrant pulling the trans apart, and you can face the switch seating surface with a lathe to gain the needed slight depth problem of the switch plunger not being far enough in the trans for the linkage to fully press the plunger in.

bick333

Thanks for the suggestions. I have pretty well confirmed the bottom switch is bad per above testing. The top switch does turn on the BU lights with the trans in reverse, so to me if I put the connector for shutting the electrical down on that switch that is working it should work. It is just a switch and does not know which connector is on it. So to have a problem with wiring past the switch or could it be a fuse? relay? Any suggestions on which one? I have seen wiring diagrams in other posts that might be of help if I knew which item I was looking fo rto replace/repair?
Again thanks for your help.

bick333

Back to square 1. had removed negative cable so battery would not go dead. pulled positive cable off of the battery. connected to negative cable for one minute. Reconnected Positive , then negative cable.
Car comes to life still ringing to put car in reverse.
Tried to start with green button - nothing , except dash going dead. disconnected negative cable. pulled relays 38,33, reinstalled, rehooked negative cable and still no cranking. or clicking that i can hear. engine light on. Theft deterrent yellow light on also. do not remember seeing this in past. Does anyone have wiring diagram that shows where the wiring ( pair of wires) from transmission reverse switch go/ connect? could you post it please.
thanks

schpenxel

I haven't read every post so maybe this is a dumb question

Jumper both connectors on the transmission with a paperclip or something similar and see what happens.

Unhooking the battery like that isn't enough. It has to see reverse in order to clear the message, even after the battery has been removed/reinstalled. Or at least that is my experience

If after jumpering the connectors it STILL doesn't shut off then let us know and I will try to dig up the wiring diagrams for the reverse signal.

4SUMERZ

Here is a wiring diagram of a 2005 C6 Manual transmission.
It may help

4SUMERZ

Reverse light circuit for 2005 C6