On my 960 3.0 the infamous arrow on the dash and the w/s/e lights on the console are intermittantly on.
Retrieved the code from the ODB system and it said 311( no RPM signal from the tranny).
The PNP switch is renewed about 4 months ago and again taken out yesterday, cleaned it (looked good, as new) and put it back on the tranny.
Renewed the BDP sensor (Vehicle Speed Sensor) on top of the bell housing and still the code comes up.
All contacts are cleaned and checked.
Is there anyone out there who can help me out....?

Thanks!!

I will try to help you out. According to the service manual I have, a 311 code is the Vehicle Speed Sensor. This code shouldn't ahve anything to do with transmission issues you indicate. If the engine speed exceeds 3390 rpm, load signal exceeds 5ms and signal absent for 3 seconds DTC 311 is set.
There are several fault sources.
1. Signal lead short circuited to live
2. Signal lead short circuited to ground
3. Break in signal lead
4. Contact resistance in connectors
5. Defective speedometer
Fault in sensor ciruit.

Unfortunately virtually all the test are done with a Scan Tool. so the procedures don't mean much without the tool.

Is the speedometer working alright? If so then check out connector 49 left A-post C2 and ECM connector for bad contact. Check lead between ECM 9 and combined instrument and ECM for bad contact.

I don't have the sevice manual Section 3 -38 to give you further information. Hopefully this will help.

Hi Warren, yes the speedo works fine, as Dan and you said I will first clean the connectors on the ECM If that doesn't work I will ask the dealer to assist with his scantool.
Thank you for your quick response.
Jaap (Rotterdam, Holland)

You might actually have two problems going on here. The flashing lights on the trans mode buttons is still probably from the PNP switch still, there is a tool that sometimes might be needed to adjust the position of the switch. It could be getting hot and the expansion is just enough to knock it of its setting. Without the special tool just loosen it and move it just a little at a time.

The code 311 VSS signal you have, I don't think is related. The sensor your post refers to is the RPM sensor that is located on top of the bell housing. The sensor for the speed come through the speedometer in the dash. I would first try before you do any replacement of parts is clean and tighten the connectors on the driver side of the transmission, very prone for faults. If that does not do the trick, try cleaning the big connector on the driverside front wheel hump, the one under the black plastic cover. If still is giving you fits then try cleaning and tightening the connector in the back of the instrument cluster.

Connector corrosion is a constant battle for me, it seems that when ever I get a code the connection is the fault not the sensor, maybe 75% of the time.

Let us know how things work out for you.

DanR 94 964 259,000 miles (25,000 on the new engine)
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DanR

Thanks Dan, I will try and clean the connectors next weekend, let you know what the outcome is.
Regards, Jaap