2002 Audi A4 with a CVT transmission and code 18185 / P1777
Discussion
I have a 2002 Audi A4 with a CVT transmission. I'm currently getting the following error code from the transmission, code 18185 / P1777. According to the repair manual it can either be the in-line filter, a restriction in the oil lines or the TCM. I have replaced the in-line filter and checked the oil lines for restrictions and did not find any restrictions. So it appears to be the TCM.
The transmission works good when cold but after it warms up (from driving for about 45 minutes) there is a delay in moving forward and when it does start to engage it is very abrupt (slam into gear) when starting from stand still. After the car starts moving the transmission works fine until you come to a complete stop then the delay in moving and engaging abruptly is repeated.
Are there any checks that I can perform to ensure that the TCM is bad?
The transmission works good when cold but after it warms up (from driving for about 45 minutes) there is a delay in moving forward and when it does start to engage it is very abrupt (slam into gear) when starting from stand still. After the car starts moving the transmission works fine until you come to a complete stop then the delay in moving and engaging abruptly is repeated.
Are there any checks that I can perform to ensure that the TCM is bad?
swagemar said:
I have a 2002 Audi A4 with a CVT transmission. I'm currently getting the following error code from the transmission, code 18185 / P1777. According to the repair manual it can either be the in-line filter, a restriction in the oil lines or the TCM. I have replaced the in-line filter and checked the oil lines for restrictions and did not find any restrictions. So it appears to be the TCM.
The transmission works good when cold but after it warms up (from driving for about 45 minutes) there is a delay in moving forward and when it does start to engage it is very abrupt (slam into gear) when starting from stand still. After the car starts moving the transmission works fine until you come to a complete stop then the delay in moving and engaging abruptly is repeated.
Are there any checks that I can perform to ensure that the TCM is bad?
I did a bit of checking and code 18185 P1777 means 163 Hydraulic Pressure Sender 2, G194. Implausible Signal (Sporadic).The transmission works good when cold but after it warms up (from driving for about 45 minutes) there is a delay in moving forward and when it does start to engage it is very abrupt (slam into gear) when starting from stand still. After the car starts moving the transmission works fine until you come to a complete stop then the delay in moving and engaging abruptly is repeated.
Are there any checks that I can perform to ensure that the TCM is bad?
It could be the sensor, the cables leading to the TCM, the TCM, or a hydraulic fault.
If the transmission works fine when cold then the TCM, cabling, etc should be OK. The fact that you get the problem when hot probably means that you have an internal hydraulic leak or that the transmission fluid is shot.
I would find an expert or this could become an expensive learning experience.
Just a thought because this is definitely not my area of expertise but if the problem only manifests when the box is hot might it be worth trying a higher viscosity transmission fluid to help maintain pressure at high temperature before replacing any expensive components?
Not really so different from putting thicker oil in the engine of an old banger to reduce oil consumption.
Not really so different from putting thicker oil in the engine of an old banger to reduce oil consumption.
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