Truck enters "emergency mode" sometimes.

The Gas and Diesel Engines - VQ40De, VK56DE, YD25DDTi, V9X, Transmission, Transfer Case, Oil, Differentials, Axles, Exhaust...

Moderator: volvite

EeJay84
Posts: 24
Joined: Fri Feb 15, 2013 4:56 pm
Location: In the deep forests of northern sweden

Truck enters "emergency mode" sometimes.

Postby EeJay84 » Sat Feb 16, 2013 8:54 am

I don't know if "emergency mode" is the right term but here is what happens :)

Before I bought it the previous owner had washed it, including the engine compartment. Afterwards the car "drove like a pile of shit" he said. The morning after it ran fine again. I bought it anyways thinking it probably had something with moist or water in some part of the ignitionsystem.

It have since the soon three weeks since I bought it went into "emergency mode" three times. It does not respond to gas and it goes to about 20mph(30km/h) on second gear and almost dies in third. As soon as I turn it off and on again it runs fine.

Engine light does not light up and there are no hidden error codes in the computer. I've changed the fuel- and oil-filters and after that it has happened once.

I assume there is some kind of an valve or indicator which "misfires" when it starts setting the engine in emergency mode. Do anyone know which one it could be that can be affected after an engine compartment wash or just water?


impulsepath
Posts: 49
Joined: Thu Jan 17, 2013 12:37 pm
Location: Raleigh, NC

Postby impulsepath » Wed Feb 20, 2013 9:19 am

The mode is called limp mode.

I would try to dry out the engine bay. Also check for water in electrical connectors, wiring harnesses, MAF etc... If you had a bad ground somewhere water would certainly not help it.

Are you positive this problem did not exist BEFORE the engine bay wash?

You need to check for codes!

EeJay84
Posts: 24
Joined: Fri Feb 15, 2013 4:56 pm
Location: In the deep forests of northern sweden

Postby EeJay84 » Thu Feb 21, 2013 2:02 am

I'm not sure that it did not exist before the engine bay wash, since I only have the sellers word for it. They seemed like honest people but you never know when it comes to buying cars :P

The computer is checked for codes and there are none.

What is the MAF?

EeJay84
Posts: 24
Joined: Fri Feb 15, 2013 4:56 pm
Location: In the deep forests of northern sweden

Postby EeJay84 » Fri Feb 22, 2013 12:49 pm

I figured out the MAF-thing :) Gonna clean it tomorrow!

I noticed that the wiring for the electrical cable to the MAF was covered in electrical tape. Gonna see how that looks beneath the tape tomorrow.

Today it happened twice that it went into "limp mode". Both was after driving fine and then stopping and idling for about a minute or more (once was at a traffic light, and the other time was at a burger drive through). When "taking off" after idling it gave no power. No check engine-light or nothing.

Today it was kinda damp outside, about 39 degrees fahrenheit (as most are american :P ). I think it has been ither damp outside or really cold with the engine getting warm and then cooling down (getting damp in the engine compartment). So maybe it is a bad connection somewhere.

EeJay84
Posts: 24
Joined: Fri Feb 15, 2013 4:56 pm
Location: In the deep forests of northern sweden

Postby EeJay84 » Sat Feb 23, 2013 1:41 am

So I cleaned the MAF today. The wiring and sensors inside almost looked charred before I cleaned it. I notice a big difference already! Torque has gone up and before it had alot of noticable smoke coming from the exhaustpipe and nothing after.

So hopefully this was it! I guess we'll see in a few days or a week :)

impulsepath
Posts: 49
Joined: Thu Jan 17, 2013 12:37 pm
Location: Raleigh, NC

Postby impulsepath » Mon Feb 25, 2013 1:38 pm

Hopefully so. MAF, mass airflow sensor measures the amount of air flowing into the engine based on which the computer decides how much fuel to deliver. I would recommend replacing it with a new one.
Once you do you will most likely find lower fuel consumption, better driveability and one less thing to worry about. :)

EeJay84 wrote:So I cleaned the MAF today. The wiring and sensors inside almost looked charred before I cleaned it. I notice a big difference already! Torque has gone up and before it had alot of noticable smoke coming from the exhaustpipe and nothing after.

So hopefully this was it! I guess we'll see in a few days or a week :)

EeJay84
Posts: 24
Joined: Fri Feb 15, 2013 4:56 pm
Location: In the deep forests of northern sweden

Postby EeJay84 » Sat Mar 02, 2013 8:39 am

So it didnt fix that problem. Now I think it has something to do with idling. It has gone into limp mode when ither idling when starting or at a stoplight. The engine has also turned itself off (due to low rpm) when gearing into neutral when stopping at a red light.


Return to “R51 Engine, Driveline and Powertrain”