2000 S40: Check Engine Light - P0705 and P1618

cameo · Post by **cameo** » 18 Dec 2011, 22:33

Hi,
I've a 2000 Volvo S40T (69k miles) and my check engine light is on. I also had a "flashing up arrow" but that went away once I pulled in the codes. Here are codes that I am seeing:

1. P0705 Transmission Range Sensor (PRNDL Input)
2. P1618 Fault in Lead between AW 50-52 and Motronic 4.3 (MIL Requested)

I tried searching the internet as well as this forum but didn't find any good hits. I also should mention that recently, I replaced the coolant thermostat (since I had P0128 code) and passenger side head light.

So, I was trying to see if anyone here can help me in fixing this issue? What could be the problem here? How could I go about diagnosing this issue?

Thanks!

Post by **zulu-v40** » 19 Dec 2011, 06:15

Seems to me like the codes are both identifying the same problem. I think AW 50-52 is referencing your transmission. I searched around a bit on google. Another person with your model year had the issue. They had the Transmission Range Sensor replaced. It's also known as the Shift Range Sensor or PNP switch or Neutral Safety Switch.

Also you could search this forum for similar problems. I found this post, which I think would be helpful to read:
viewtopic.php?f=1&t=9992
In the post, they talk about the arrow you witnessed flashing, asserting it's a symptom of the above mentioned sensor malfunctioning.

cameo · Post by **cameo** » 20 Dec 2011, 22:15

Okay, thanks Zulu.