Friday, June 27, 2008

crankshaft position sensor installation

How to remove and replace the crankshaft position sensor or "CPS" on the SAAB 9-5

Start with a completely cold engine. You will be right against the exhaust during this repair and it's going to be uncomfortable enough without adding some 2nd degree burns to your hands.

Unhook and remove the battery and battery tray from the car. Removal isn't essential, but it will make it easier to route the wire bundle at the end of the install. Unhook the battery to prevent electrical problems at the very least.

Remove the diverter valve (DV) from the intake and the aluminum recycle tube from the turbo. Remove the aluminum heat shield between the engine and turbo. There is one nut and two clips holding it.

The CPS is located on the lower left front of the engine, near the transmission and behind the catalytic converter. You might spray the one Torx screw with some liquid wrench.

Use a T30 Torx bit and whatever contraption you can find in the way of a wrench setup that fits the area to remove the one screw on the lower right of the CPS heat shield. I used a small ratcheting "L" shaped screwdriver to loosen the screw and then used my fingers an a 3/8in Torx socket once the screw was loose.

The heat shield will come off with the screw. The Crankshaft position sensor will come out with a slight twisting/rocking motion as you pull. Follow the cable to the right of the throttle body near the firewall. The connector was the first of three in a row (light blue in the photo below). It unhooks like all SAAB connectors, with a small screwdriver prying the red lock loose. There is a metal cuff that holds the cable to a pipe midway between the CPS and the connector. It can be pulled off with your fingers.

Clean the hole where the CPS goes and make sure the rubber washer on the old CPS is out. You don't want two washers in that hole.

Push the new crankshaft position sensor into the hole. It will go most of the way with little effort, but a hard push/twisting motion will be needed to completely seat it. Really cram it in there and line up the screw holes as best as you can. You will want to thread the screw without the shield first, just to make sure your holes are lined up first. Then remove the screw again, add the heat shield, and re-thread the screw back into place. This will take some effort and time. The screw will not want to start threading and the area is really tight.

Once the screw is finger tight, use your T30 size Torx wrench setup to tighten it the rest of the way.

Re-route the wire bundle back to its cradle next to the throttle body and install the metal cuff  onto the cable/pipe. Reconnect the cable to the car, install the battery, heat shield, and everything else removed for this project. Clean up the area, put your tools away, and start the car.


  1. managed to do it in 30 mins, without removing anything other than the broken sensor. Car sorted.

  2. HEY!!! love your threads!! just had a question that maybe you can help me with. So my 99 Saab 9-5 2.3L T has bin acting up lately. Sometimes in the morning it wont start for maybe 10 or so minuets, sometimes when i drive for a bit, park and then come back to start it, it wont start for about 10 or so minuets. What can this be?? my starter is good because my engine cranks over when i turn the key and i bought new spark plugs for it and my fuel pump is good also. Could this be CPS??

  3. These are classic CPS failure symptoms. It's an easy fix and not too expensive (by SAAB standards). Just make sure the car is cold when you replace the CPS or you'll burn your hands.