98 Expedition, 4X4, 5.4l,, OD light started flashing, everything ran fine, But now engine has a bad miss and will stall when stopping..No Check engine light..Would the Trans cause the engine to Miss or what could be wrong. I read here the flashing light indicates tranny problem, but would it make the engine miss?

Thanks, Ted O.

 

Get your code(s) scanned, they are your first source of failure data.

WRITE THEM DOWN, then either SEARCH or ask.

Steve

 

This site should sell code readers for a deal (but profit) to its members. They are soo worth it.

I got a nice new Actron for $50 delivered on eBay.

 

There are no codes, Check engine is not on...

 

As I understand it, if the OD light flashes, it's sent a code to the computer. Codes can be stored without the CEL flashing.

Sounds like your torque converter maybe the issue?? Like it's not unlocking or something??

Anyway, I'm sure there is a code if your OD light is flashing....

Good luck!

Mitch

 

The transmission codes are not stored there so an OBD2 read would not reveal that.

Usually that means transmission is overheating. Did you change the fluid with something other than Mercon V?

Also could be a speed sensor.

Unhook the battery for a while. It may go away.

 

I have an AutoXray reader, No codes,, unhooked battery at the start of this for 1 day,,still there, as rough as its running,,can't understand why no check eng. codes...

 

Transmission faults do not throw check engine codes. They are read from the transmission memory.

 

Well now getting P0300 code,, random misfire. still no check eng. light, but I don't think tranny problem would set this code..

 

rutherk1,

Good thing to know! Thanks.

Houndog,

Sorry for that wrong info..... I know they can pull the tranny codes as well, just thought there was only one com port to pull from??

What 'port' do you connect to get the tranny codes?

 

Thanks Mitch,, good question, how do we read tranny codes..??

 

The transmission does not have it's own computer, it is controlled by the PCM. Any tranny-related code (if set) will be pulled at the same time as any engine management codes, there is no difference.

Make certain you also check for pending codes. These can indicate problems that the computer has found but have not yet reached the threshold (frequency or severity) at which it turns on the CEL or sets a "solid" code.

Check your scanner's operating instructions to see if you can pull freeze-frame data or if you can run the KOER self-test under OBD-II.

If you don't already have on, get a copy of the service CD for your truck and study the PCED section on how the system works and how diagnostics are performed. Understanding this can help you greatly.

Steve

 

Thanks Guys,, Getting a P0304 pending now, so looks like CP #4 again..The hardest one to get to...

 

Check the heater line connector directly overhead of the #4 COP. It likes to leak onto the #4 COP and cause repeated failures.

Steve

 

Thanks Steve,, will do..
Ted O.