# Key Light stays on w/2603 code



## Joe_Rumsey (5 mo ago)

Hello everyone,

Am new to the site and am asking for help amongst the Sentra family owners to see if anyone has encountered my situation.

Have a '13 Sentra SL that has the "Key" light illuminated in yellow on the dashboard. It also has a BCM code p2603 stored for shift position. So, you can clear out the "key" light and will stay out on the dashboard until you try to shift from "Park" to "Reverse"...it will then immediately come back on. 

Took it to the Nissan dealer and was informed that "Technician found DTC B2603 shift statur triggers every time moving out of park. Detent switch never changes status. Will need the shifter to be replaced to correct.

Was informed that is about a $750 job and not something that is seen often. So, decided to go the used part route and have my mechanic install it. And have now been informed by my mechanic that nothing has changed regarding the "Key" light being illuminated. 

Have searched all over the internet for Nissan vehicles having similar issues and have came up with only one other vehicle having the same issue (an Altima) that someone had posted on AltimaForums.net and none replied to him.

So with this being an uncommon issue, am suspicious of the dealership "misdiagnosing" the problem...and it being a coincidence that have encountered 2 bad shifters.

Any help with this issue from any of the members would be greatly appreciated.

Thanks in advance.


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## Oldcivicjoe (Jun 21, 2021)

Saw this on an altima, customer had thrown roughly 6000 at it , including shifter, trans, bcm, several dealer diagnostic charges, and several independent shop diagnostic charges, as far as I know there still hasn't been a solution figured out, I spent hours checking continuity on every wire that goes from shifter to bcm or trans, and trans to bcm, also was able to talk the dealers into replacing the already replaced parts again and nothing changed. So far as I know a solution hasn't been found yet, but I'll make an inquiry for you.


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## Joe_Rumsey (5 mo ago)

Oldcivicjoe,

Am appreciative of help and inquiry on this issue.

Please post back if you find out anything.

Thanks


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## Oldcivicjoe (Jun 21, 2021)

I put in a call, waiting on an answer back.


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## VStar650CL (Nov 12, 2020)

There was actually a bulletin about B2603 in some Altimas, Rogues, and Pathies from misadjustment of the transmission Range Switch:


https://static.nhtsa.gov/odi/tsbs/2015/MC-10192643-9999.pdf



Although the bulletin was for factory misadjustment on those cars, the system on your Sentra is identical. The BCM throws that code when the detente switch in the shifter and the Range Switch on the tranny disagree in a nonsensical way. The detente switch should show one voltage in Park and another when in gear or the button is pushed (I forget which is +V and which is 0V). On the Range switch pin 7 should have power with the key, pin 10 should show 12V in P or N, 0V in any gear. One of those switches is either misadjusted or not working, or else you have a wiring problem. Check the switches first, there's an excellent chance you just have a misadjusted Range Switch as shown in the bulletin.


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## Oldcivicjoe (Jun 21, 2021)

So the altima was actually something shorted in the cluster, I guess someone (the husband I think) spilled coffee at some point in time, and somehow that is what triggered the issue for that one, it sat until a friend of theirs did the same thing, except their friend had that issue and many others pop up nearly immediately after the spill. They replaced the cluster (used) then had to have something or other programmed. Probably not your issue and more likely what Vstar stated above, unless you are in the habit of spilling on your dash, lol.


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## VStar650CL (Nov 12, 2020)

Oldcivicjoe said:


> So the altima was actually something shorted in the cluster, I guess someone (the husband I think) spilled coffee at some point in time, and somehow that is what triggered the issue for that one, it sat until a friend of theirs did the same thing, except their friend had that issue and many others pop up nearly immediately after the spill. They replaced the cluster (used) then had to have something or other programmed. Probably not your issue and more likely what Vstar stated above, unless you are in the habit of spilling on your dash, lol.


If I had a nickel for every part I've replaced whose underlying defect was coffee or soda pop, I'd be a very rich man. You too, I bet.


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## Oldcivicjoe (Jun 21, 2021)

VStar650CL said:


> If I had a nickel for every part I've replaced whose underlying defect was coffee or soda pop, I'd be a very rich man. You too, I bet.


Most certainly🤣


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