I just got my car back from the shop after putting a new engine in it. They told me everything was fine except the up arrow was flashing and the modes were blinking back and forth from E to W and the CEL was on. It was also throwing a P0500 code (speed sensor).The mechanic told me to replace the PNP switch and I will be fine. I had to do this myself because this new engine cost me 3k to put in and I am now broke. So I bought a new PNP switch from Volvo for $170 and did it myself, well it did not change a thing, I am still in the same boat. Keep in mind I have never driven this car before, I bought it with a blown engine. So I don't know if it was like this before the engine replacement or not. After I replaced the PNP would I have to manually reset the computer? Please help, I don't know what to do next.

 

Why would you get a car with a blown engine? Just wondering. I would guess that something is wrong with the speed sensor if that is the error message you are getting. But do wait for a pro to lead you.

 

I bought the car for $760 in mint condition, It is a one owner with every receipt and brand new goodyears. Only had 125,000 miles. I couldn't stand to see a car this nice get parted out. (The lady always kept up on T-belts but never had the tensioner replaced so good-bye engine.) Looking at the equivalents online, they go for about what I have in it now. Plus now I have an engine with 70,000 documented miles. If I could just get this one thing fixed I'd have a perfect 960. This is really frustrating, Is there a way to test the speed sensor? Is it a harness the shop could have missed while putting the engine in, or something they could have done?

 

I do understand that the car could bring what you have into it. I just sold mine for $4,500 and it had a dent in the hood.

I'm kinda surprised that the shop that got paid to install the motor wasn't responsible for making sure all codes were clear. Is the car limping? Maybe getting the codes cleared will cure your problem unless you guys already tried that.

BTW, I did replace the t-belt in my 960 at 60k and again at 87k because the idler roller was going bad. It happens. I have actually started writing all changed related parts on my t-belt sticker.

 

This is Volvo's procedures for checking the Rear (Vehicle Speed Sensor):

Rear (Axle) Speed Sensor

1) Disconnect ABS-ECU connector. Connect DVOM between ABS-ECU connector terminals No. 7 and 9. Resistance should vary from 600-1600 ohms as rear wheels are rotated.

2) If resistance is not within specification, check sensor resistance at sensor connector at fuel filler pipe in trunk. If resistance is within specification, repair wiring harness to ECU. If resistance is not within specification, replace sensor.

3) On vehicles without multi-link axle, if gap between sensor and pulse wheel is greater than .007" (.2 mm) or has damaged teeth, sensor gives incorrect signals and must be replaced.

 

Is your speedo working?