S40 transmission problem
#1
S40 transmission problem
I have a 2001 S40 Volvo. Recently, the check engine light came on as well as the flashing arrow indicator which means a transmission malfunction. Using an OBDII reader, I found the codes P0700 and P0798. P0700 is a "transmission control error" and P0798 is a "pressure control solenoid C electrical" error. Does anyone know what is required to fix this problem? Is the pressure control solenoid part of the electronic control module and I have to replace the whole module, or is the pressure solenoid separate and can be replaced separately? And where is it located?
#3
RE: S40 transmission problem
No, I didn't try to clear them. I wanted to keep them there if I had to take the car to the shop. I did download the online manual to the car. It said that there is a Transmission Control Module in addition to the Electronic Control Module, and it has separate diagnostic codes. The ECM codes won't clear unless you clear the TCM codes first. I only have a simple OBDII reader, and I don't think it'll work on the TCM.
I figure it has to be either the solenoid or TCM module. Do you know which one has a history of greater failures in this car?
I figure it has to be either the solenoid or TCM module. Do you know which one has a history of greater failures in this car?
#5
RE: S40 transmission problem
Well, I took the car into the Volvo dealership. They said it was the SLS solenoid which controls the line pressure in the transmission. The error code was TCM-0114 which is:
"Line pressure solenoid SLS regulates the line pressure in the transmission. The solenoid is controlled by a power stage in the transmission control module (TCM) output. The transmission control module (TCM) uses the power stage to control the current to the solenoid. A low amperage results in a high line pressure. A high amperage (approximately 1 A ) gives a low line pressure. The amperage is primarily affected by the throttle position. Diagnostic trouble code (DTC) TCM-114 is stored if the control module registers that there is an open-circuit in the circuit for solenoid SLS. Solenoid SLS cannot then control the line pressure."
They wanted $1600 to fix it. They said they can't replace the SLS solenoid by itself since Volvo only sells the module that contains all of the solonoids, and that costs $960. Then add 6 hours of labor. They also said they couldn't measure the resistance across the solenoid for whatever reason - which is what the manual recommends.
Looking at the description of the error code, it says that it is generated when there is an open-circuit in the circuit for the SLS solenoid. Being as the car is now functioning properly, it appears that the problem is intermittent and not a "definitely this is broken" problem. I would think that if the solenoid was bad, it would have a continuous open, not intermittent. This leads me to think that the problem is a bad connection in the harness or connector part of interface. So I told them to clean things up and wait and see if it happens again.
Any thoughts?
"Line pressure solenoid SLS regulates the line pressure in the transmission. The solenoid is controlled by a power stage in the transmission control module (TCM) output. The transmission control module (TCM) uses the power stage to control the current to the solenoid. A low amperage results in a high line pressure. A high amperage (approximately 1 A ) gives a low line pressure. The amperage is primarily affected by the throttle position. Diagnostic trouble code (DTC) TCM-114 is stored if the control module registers that there is an open-circuit in the circuit for solenoid SLS. Solenoid SLS cannot then control the line pressure."
They wanted $1600 to fix it. They said they can't replace the SLS solenoid by itself since Volvo only sells the module that contains all of the solonoids, and that costs $960. Then add 6 hours of labor. They also said they couldn't measure the resistance across the solenoid for whatever reason - which is what the manual recommends.
Looking at the description of the error code, it says that it is generated when there is an open-circuit in the circuit for the SLS solenoid. Being as the car is now functioning properly, it appears that the problem is intermittent and not a "definitely this is broken" problem. I would think that if the solenoid was bad, it would have a continuous open, not intermittent. This leads me to think that the problem is a bad connection in the harness or connector part of interface. So I told them to clean things up and wait and see if it happens again.
Any thoughts?
#6
#7
It sounds to me that they are speaking of the linear solenoids in the valve body. These are only a couple hundred dollars or you can get a completely rebuilt valve body and put it on yourself. I just replaced all of the solenoids in my 2001 S40 and it wasn't a big deal. Look for the YouTube videos on the subject!
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