Code P27B6 With Code P0600

[Replicator]

Just wanted to share an experience since I didn't find much info on it when it just happen to me.

Today I was doing some spirited driving. One of the times I got on it the car went to the top of 3rd and instead of shifting it fell flat on its face. The engine bounced off redline (10R80 in regular drive mode) before falling down to idle with no transmission engagement. I slowed down and started pulling off when the transmission suddenly reengaged. Along with this I got the wrench on the dash signaling a drivetrain issue. Another thing I instantly noticed is the car would barely run when accelerating feeling like it was sputtering/misfiring/stumbling along with backfiring. The rest of the way home I struggled to get over 50 with it very rarely giving me a second of smooth acceleration. I observed any time I let off the accelerator the rpm would instantly drop to idle and the car would coast like in neutral. Car revved without issue in park and neutral.

Once home I instantly hooked the laptop up to it to pull DTC. The two codes I pulled were:

P27B6: Which signifies transmission speed sensor issue.
P0600: Which is a serial communication fault.(could be sensor or module)

Me being the brazen troubleshooter I am, I instantly cleared these codes and took the car for another spin. The issue came back as soon as i started going in drive. I almost didn't make it back up the driveway. Ok I guess I'll work for this one. After getting under the hood and checking all the connections I got it up in the air and did the same underneath. Nothing. Nothing at all. Time to call my friend Google. Nothing. No help. Seriously. I'm going to have to take this to a dealer? No way!

After a couple hours of this, many failed trips down the road, and my neighbor asking if I wanted to race his Husqvarna for pinks I had an idea. Based off the P0600 code I figured. Why not just reflash everything? I wonder if something software side became discombobulated. 6 minutes later I'm turning the car on and driving down the road without fault. I've put a little over 100 miles on it since without being able to recreate the issue. If it does happen again I'll get the speed sensor replaced. I cannot nail down a root cause.

Specs:
2019 Mustang GT
10spd Auto
Roush/FP supercharger
SP 1⁷/8 - 3" LT offroad headers
Custom midpipe
Roush Axleback
Methanol injection
PBD 93 Tune

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[Phillymane]

Hey did you ever find the problem with this code?

 

[Replicator]

Hey did you ever find the problem with this code?

My best assumption looking back on it is that the transmission was shifting gears and something happen that caused it to not make it into gear. This probably happen at a time when the PCM thought it was in one gear when it was actually still in the other. This probably caused a mismatch between engine speed and transmission speed throwing the car into limp mode. Downloading to the car "re-zeroed" all the values which is why it probably started working again. When I took the car in for service a few thousand miles later I had them check the transmission fluid level which turned out to be at the bottom of the range. The issue never returned.

 

[Phillymane]

My best assumption looking back on it is that the transmission was shifting gears and something happen that caused it to not make it into gear. This probably happen at a time when the PCM thought it was in one gear when it was actually still in the other. This probably caused a mismatch between engine speed and transmission speed throwing the car into limp mode. Downloading to the car "re-zeroed" all the values which is why it probably started working again. When I took the car in for service a few thousand miles later I had them check the transmission fluid level which turned out to be at the bottom of the range. The issue never returned.

 

[Phillymane]

I had something so laid happen to me. I was racing while in second gear, i redline it & transmission start shifting like crap & my vacuum pressure stayed below 10. I made it home barley & I put my turner in and reset my engine code. (P0600, P27B6)

After I clear the codes, my car started shifting normal again but it’s jerking a little at 2500 rpm’s before shifting. I’m thinking it’s a communication between the ecu & trans that’s causing it but I’m just trying to find answers before I give in & take it to the dealer. Not much info about these codes online. Thanks for the reply

 

[Replicator]

I had something so laid happen to me. I was racing while in second gear, i redline it & transmission start shifting like crap & my vacuum pressure stayed below 10. I made it home barley & I put my turner in and reset my engine code. (P0600, P27B6)

After I clear the codes, my car started shifting normal again but it’s jerking a little at 2500 rpm’s before shifting. I’m thinking it’s a communication between the ecu & trans that’s causing it but I’m just trying to find answers before I give in & take it to the dealer. Not much info about these codes online. Thanks for the reply

If you have an aftermarket tune then re-flash that.

 

[Phillymane]

I just reflash my tune yesterday but still the same problem. I have a schedule appointment with my turner & I’ll give you a update.

 

[SilverUri]

Just wanted to share an experience since I didn't find much info on it when it just happen to me.

Today I was doing some spirited driving. One of the times I got on it the car went to the top of 3rd and instead of shifting it fell flat on its face. The engine bounced off redline (10R80 in regular drive mode) before falling down to idle with no transmission engagement. I slowed down and started pulling off when the transmission suddenly reengaged. Along with this I got the wrench on the dash signaling a drivetrain issue. Another thing I instantly noticed is the car would barely run when accelerating feeling like it was sputtering/misfiring/stumbling along with backfiring. The rest of the way home I struggled to get over 50 with it very rarely giving me a second of smooth acceleration. I observed any time I let off the accelerator the rpm would instantly drop to idle and the car would coast like in neutral. Car revved without issue in park and neutral.

Once home I instantly hooked the laptop up to it to pull DTC. The two codes I pulled were:

P27B6: Which signifies transmission speed sensor issue.
P0600: Which is a serial communication fault.(could be sensor or module)

Me being the brazen troubleshooter I am, I instantly cleared these codes and took the car for another spin. The issue came back as soon as i started going in drive. I almost didn't make it back up the driveway. Ok I guess I'll work for this one. After getting under the hood and checking all the connections I got it up in the air and did the same underneath. Nothing. Nothing at all. Time to call my friend Google. Nothing. No help. Seriously. I'm going to have to take this to a dealer? No way!

After a couple hours of this, many failed trips down the road, and my neighbor asking if I wanted to race his Husqvarna for pinks I had an idea. Based off the P0600 code I figured. Why not just reflash everything? I wonder if something software side became discombobulated. 6 minutes later I'm turning the car on and driving down the road without fault. I've put a little over 100 miles on it since without being able to recreate the issue. If it does happen again I'll get the speed sensor replaced. I cannot nail down a root cause.

Specs:
2019 Mustang GT
10spd Auto
Roush/FP supercharger
SP 1⁷/8 - 3" LT offroad headers
Custom midpipe
Roush Axleback
Methanol injection
PBD 93 Tune

Any update?

 

[Replicator]

Any update?

The issue never came back after reflashing the car. My best assumption is an issue happened when the tune was first loaded.

 

[SilverUri]

The issue never came back after reflashing the car. My best assumption is an issue happened when the tune was first loaded.

Thx. Have a good day!

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