A/T check light on

Forum for Infiniti M35 and M45, and Nissan Fuga owners.
JJM158
Posts: 53
Joined: Mon Sep 02, 2019 7:25 pm
Car: 2007 Infiniti M35 S

A/T check light on

Postby JJM158 » Mon Apr 26, 2021 6:27 pm

Hi this morning my A/T check light came on, not flashing but solid. I noticed throttle lag until about 2k rpms and seems like trans stays in one or two gears when accelerating. I scanned using my obd2 device and a P1815 code ran


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Ilya
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Car: 2011 M56x but I spend a lot of time on my 2015 Kawasaki Vulcan S. Former owner of a 2007 M35x. Also take care of my wife's 2016 QX60.
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Re: A/T check light on

Postby Ilya » Mon Apr 26, 2021 8:07 pm

How many miles on your car? How often was the transmission serviced? Is this for the 07 M35S in your profile?

JJM158
Posts: 53
Joined: Mon Sep 02, 2019 7:25 pm
Car: 2007 Infiniti M35 S

Re: A/T check light on

Postby JJM158 » Tue Apr 27, 2021 4:30 am

Yes it is for my car on my profile and had transmission fluid flushed and replaced last year.

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VStar650CL
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Car: 2013 Nissan Altima 2.5 SL
2004 Nissan Altima 2.5 S

Re: A/T check light on

Postby VStar650CL » Tue Apr 27, 2021 5:07 am

P1815 is kind of a "plausibility" code for the Manual Mode switches, like the TCM seeing two gears at the same time, etc. The chart on AT-94 defines it as, "When an impossible pattern of switch signals is detected." It's usually electrical and not a problem with the tranny per se, but since the TCM on your trans is built into the valve body, your VB or TCM might have a problem. I can't get into ASIST right now to see if the DTC has a failsafe condition, but there's a good chance it does and your laggy/non shifting is a result of limping in failsafe. It's possible the TCM just had an electrical glitch, so I'd try simply erasing it to see if things improve and whether it re-occurs.

JJM158
Posts: 53
Joined: Mon Sep 02, 2019 7:25 pm
Car: 2007 Infiniti M35 S

Re: A/T check light on

Postby JJM158 » Tue Apr 27, 2021 5:23 am

So do a Ecu reset? I plan on hearing from the dealer to get their opinion?

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Ilya
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Posts: 9395
Joined: Fri Apr 23, 2010 11:20 pm
Car: 2011 M56x but I spend a lot of time on my 2015 Kawasaki Vulcan S. Former owner of a 2007 M35x. Also take care of my wife's 2016 QX60.
Location: Tampa, FL
Contact:

Re: A/T check light on

Postby Ilya » Tue Apr 27, 2021 5:34 am

Not sure an ECU reset will affect the TCM. You may have to disconnect the battery for a few hours? VStar can confirm the process.

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VStar650CL
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Car: 2013 Nissan Altima 2.5 SL
2004 Nissan Altima 2.5 S

Re: A/T check light on

Postby VStar650CL » Tue Apr 27, 2021 6:06 am

No, I doubt the code is current, that sort of "I'm confused" situation is usually come and go. Just erase it with the scanner.

JJM158
Posts: 53
Joined: Mon Sep 02, 2019 7:25 pm
Car: 2007 Infiniti M35 S

Re: A/T check light on

Postby JJM158 » Tue Apr 27, 2021 7:05 am

my battery was disconnected overnight before this happened. So will the TCM cause my slow acceleration issue, as it feels the trans is starting out in a 3rd or 4th gear.

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VStar650CL
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2004 Nissan Altima 2.5 S

Re: A/T check light on

Postby VStar650CL » Tue Apr 27, 2021 7:25 am

JJM158 wrote:
Tue Apr 27, 2021 7:05 am
my battery was disconnected overnight before this happened. So will the TCM cause my slow acceleration issue, as it feels the trans is starting out in a 3rd or 4th gear.
If it's in a failsafe because of the code, yes. As mentioned, I suspect it is.

JJM158
Posts: 53
Joined: Mon Sep 02, 2019 7:25 pm
Car: 2007 Infiniti M35 S

Re: A/T check light on

Postby JJM158 » Tue Apr 27, 2021 7:26 am

Is there a procedure where I can reset/relearn my TCM?

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VStar650CL
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Car: 2013 Nissan Altima 2.5 SL
2004 Nissan Altima 2.5 S

Re: A/T check light on

Postby VStar650CL » Tue Apr 27, 2021 7:28 am

Not that I know about, but if the DTC shows "past" then it should simply erase. That will clear any failsafe until/unless the condition recurs.

JJM158
Posts: 53
Joined: Mon Sep 02, 2019 7:25 pm
Car: 2007 Infiniti M35 S

Re: A/T check light on

Postby JJM158 » Tue Apr 27, 2021 7:47 am

I can clear the p1815 code as it could be old, this light has never came on before, and no code about my current issue

JJM158
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Joined: Mon Sep 02, 2019 7:25 pm
Car: 2007 Infiniti M35 S

Re: A/T check light on

Postby JJM158 » Tue Apr 27, 2021 7:51 am

could the dealer look into the DTC and go from there?

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VStar650CL
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2004 Nissan Altima 2.5 S

Re: A/T check light on

Postby VStar650CL » Tue Apr 27, 2021 8:34 am

There isn't much to look into with a P1815 unless it's from an external wiring issue. If it's a glitch it won't return after erasure. If it keeps coming back then it usually means bad contacts on one of the switches in the valve body, so you'll need a new VB.

JJM158
Posts: 53
Joined: Mon Sep 02, 2019 7:25 pm
Car: 2007 Infiniti M35 S

Re: A/T check light on

Postby JJM158 » Tue Apr 27, 2021 8:41 am

Not look into the code but just in general to see what else could be causing my current issues.

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VStar650CL
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2004 Nissan Altima 2.5 S

Re: A/T check light on

Postby VStar650CL » Tue Apr 27, 2021 8:45 am

Same deal, erase the code and see if the tranny is simply limping because of it. If it goes back to normal after erasure then it was limping, if it doesn't then you have a different problem,


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