P0658 Code and Limp Mode on Start

[TrickerZ]

Pretty much every time I turn my Expedition on, I get a P0658 code and the transmission goes into limp mode. If I reset the TCM, everything is fine until I restart the car. I checked all the cables and connectors going to the TCM and they all look good. I haven't tried spraying them out with contact cleaner, yet, but that's probably my next step.

Has anyone run into this? I did a search and did not find the code at all on this site. On Google I found some responses, but nothing really solid. Do I need to drop the transmission pan and check voltage at the actuators? It seems like the actuators are fine since the transmission has been switching fine.

 

[chuck s]

What year truck/engine?

-- Chuck

 

[07navi]

What all does the limp mode do on these and always put the year in at least.

 

[TrickerZ]

What year truck/engine?

-- Chuck

It's a 2007 Limited 5.4L with 4WD.

 

[TrickerZ]

What all does the limp mode do on these and always put the year in at least.

Yeah, sorry. I thought I did. Limp mode keeps the transmission in a single gear, usually 3rd, to help prevent damage to the transmission.

 

[07navi]

Yeah, sorry. I thought I did. Limp mode keeps the transmission in a single gear, usually 3rd, to help prevent damage to the transmission.

I guess that is how you know you are in limp mode ......3rd gear only. Mine did that too when I left the MAF unplugged.

 

[TrickerZ]

I'm really surprised no one has ever seen this code. I guess I'm just lucky.

 

[TrickerZ]

So, I've found that if I wait until all the electrical is up and running before starting the vehicle, I don't run into this issue. I'm thinking it's a bad ground somewhere that's causing inrush to pull the voltage too low for the TCM. Anyone have any ideas on where the grounds are I should check?

 

[Yupster Dog]

So, I've found that if I wait until all the electrical is up and running before starting the vehicle, I don't run into this issue. I'm thinking it's a bad ground somewhere that's causing inrush to pull the voltage too low for the TCM. Anyone have any ideas on where the grounds are I should check?

Voltage Drop Test There is a sticky on it in the electrical section. Start at the battery cables positive and negative.