Intermittently my 1997 XJ6 will stall when slowing down. The transmission light then comes on and the car is clunky when shifting into drive. Diagnostic test showed it was the Mass Air Flow; which I changed, however it continues to do the same thing. It will seemingly come out if it on its own. The light goes off and car runs normally again. Any advice is greatly appreciated.

 

The engine and transmission ECU talk to each other and if there is a miss match of signals it will stall the engine . You have changed the MAF . But to verify that it's working correctly you will read 1.2 volts DC on the middle wire at the correct idle speed .This goes up toward the reference voltage of 5.0 on throttle up .

The on the transmission body connector it gets dirty which corrupts the signal ( s ) to the transmission ECU

What kind of diagnostic tool are you using ?

Since you are getting a light , would that be a CEL code ? The auto parts store will read it for free .

 

 

With your fluctuations on the electrical voltage you could drop below the 11.4 volts for proper ECU operation .That would be the first area to address .
Do you ever get a alternator light ?
Put it a better way ( you will ultimately get the alternator light as the engine stalls ) While the engine is operating before the stall do you get the light ?
Have you gone through the electrical power cables to ensure good connections ?

 

 

That is the transmission light. It's illumination is rather normal when the engine stalls whilst the car is rolling. The car is offended that the transmission is reporting it's in motion while the engine is reporting at rest. As you initially reported, engine stalls, then the xmsn light illuminates. Find and fix the stall initiator, and your transmission concerns will likely be in your rear view mirror.

 

Can someone post the pic in the owners manual so the discussion on this light or that light is clarified and not mixed in the troubleshooting one path or another path .

The quality of the electricity is very important in a electrically regulated vehicle and I'm with Aholbro1 in squaring away this foundation area will probably resolve the regulation issues in a separate electrical generation path ..

 

This is from the Drivers Handbook which if you don't have a copy can be downloaded and decompresses from a Zip file here . This way you can see the lights meaning accurately .:

http://www.mediafire.com/file/coqyrm...rs+Handbook.7z

It's not realistic to remember which lights or voltage readings you had before and during the point the fault accrues . A separate observer would be recommended so you can keep your attention on the driving

One thing to keep in mind is the car's voltage meter is dampened and may not show the voltage dropping into the forbidden zone if it is or is not accuring . It only takes a second to effect your ECU .

The cars meter may not be accurate and the angle at which you read it . A second digital meter plugged into a inside power source with you observer monitoring this would be better ..

If you pull out the stereo head you can get a power source / reading from there .As a US car this would not be a problem for the stereo's security code but it would be for other areas of the world .

 

Hrmm, another stalling while dropping to idle, then stop issue. I keep saying this is becoming a trend over the last few years, with most threads never reporting a solution. Do a search for "stalling when stopping" and see how many threads there have been, including mine, and it is a bit of an eye opener.

I really think there is a common issue that we've yet to discover.

It is often pointed out that it could be transmission related, especially low fluid. However I see two problems with that. First, we aren't finding that owners with this issue are reporting back with low fluid. I know in my situation the fluid level is good. Second, the cars are stalling usually when coasting to idle, so even if the torque converter isn't unlocking properly I would think it would be a more abrupt stall not a stumble then stall?

I unfortunately don't have anything helpful to offer at the moment as I'm still searching for my problem going on 6 months, and I've changed just about every sensor and power source. This is a really frustrating issue.

If you find out what is causing yours, please let us know!

.

 

That kind of stall is often due to an air leak.

The later cars store a code ("flight recorder" data) with details of what happened. Do these cars?

 

mine did the same.. died at almost every stop. I changed the maf, plugs and the O2 sensors and it cured the problem. Not sure which of the 3 that was the solution. it might have been a combination i suppose.

 

Thanks!

Of those three, I'd suspect the MAF first, and I'd suspect the O2 sensors least as far as potential cause of a stall, but who knows.....

I think someone recently posted an aftermarket supplier of a MAFs now available.