- All
- New
- Pre-owned
5stars
1rating4stars
1rating3stars
0rating2stars
0rating1star
0rating
Would recommend100% agree
Good value100% agree
Good quality100% agree
2 reviews
Used sensors may soon fail
This particular design (illustrated above), with the short cable and ten-pin Micro-Power-Timer connector, was employed in 1999 through 2001 models. Later model sensors have no cable.
Rating:
Rather than rely on luck, I have already installed a bypass switch. WHEN my NSS fails, I will not be stranded, nor delayed.
I have provided a procedure for thoroughly testing your NSS sensor. Be sure to install and test yours promptly. I feel that a 30 day warranty on used parts is inadequate, but that is certainly long enough to Install, Notice a DOA part, Remove, and Return it under warranty.
Why Is There A Nut:
The Neutral Safety Switch (NSS), or Transmission Range Sensor, detects the angular position of the transmission selector shaft. A nut clamps the moving parts of the sensor to the selector shaft, eliminating slack-backlash-hysteresis. Brilliant! Be sure to loosen this nut before removing the sensor, and tighten after installing and before the final alignment.
There are two mounting bolts running through elongated holes in the sensor body. This allows the sensor to be rotated to alignment with the transmission. Be Very Careful not to drop or tilt the bolt spacers that are between the sensor and transmission!
It is well known that SAAB NSS's may fail intermittently, usually after the transmission has warmed up. If you want to know if your present or replaced NSS sensor has this problem, try the following tests:
Drive for only 30 minutes, then shut off the engine and Set the Parking Brake Firmly. The tests are conducted while the transmission and sensor cool down.
The Test:
Immediately, and at ten minute intervals for the next 40 minutes, turn the key to "ON" and put the shifter in "3". (In 3rd gear, all five encoder switches are closed.) Confirm that the same indication is displayed on the dashboard. Shift to Reverse and check your reverse tail lights outside. Shift to Park and turn the key to Start - just long enough to hear/feel the starter motor. (If you also test the Neutral position, please note: the Start position Only Works Once.) Turn the key to "Off" and remove the key. Repeat tests every 10 minutes until 40 minutes has elapsed. That should catch it acting up.
How It Works:
The sensor has three circuits. The namesake circuit detects when the transmission should be out-of-gear. In Neutral and Park, switches connect pins 6 and 10 to enable the starter relay (under the dashboard). A second circuit will connect pins 7 and 9 in Reverse. This energises the white tail lights. The last circuit is the most complicated; encoding all transmission selector positions for the engine computer. There are 13 states or encodings: P, R, N, D, 3, 2, 1; and six more in-between those seven normal positions. All this is encoded in binary as continuity on pins 1 through 5. Pin 8 is common. Even if the encoder comes to rest in a between-position state, the computer uses the latest adjacent position. Absolutely brilliant!
FAILURE MODES:
Original NSS sensors will be over 15 years old. The age is not relevant, but the number of thermal cycles during that time is the problem. The sensor gets quite hot, bolted to the transmission. Underneath and within the "potting compound" of the sensor are ten cable crimp connectors. The rigid potting compound is bonded to the sensor housing, cable insulation, wire strands, crimp connectors and "busses". Because these components all have different rates of thermal expansion, thermal cycling will eventually loosen these electrical connections. The signals are also likely passed in "plated-through-holes" in the circuit board. If these holes are not filled and capped with solder, the connections there can fail.
A few sensors may fail due to metal oxides that wear off and accumulate inside the housing. Brush compression springs may break. All these are uncommon, as the mechanical design is very robust.
To be competitive, new NSS manufacturers should offer a prorated warranty of at least five years, but I Don't See That Happening. All I see are 30 and 90 day warranties for New parts! One user has claimed that a New sensor failed in under 3 years, but surely that must be an outlier experience?Read full review...
Verified purchase: Yes | Condition: pre-owned | Sold by: massusedautoparts1
Easy DIY swap
I literally removed the old and installed this one in 20 minutes. Use care when removing the old one, but should slide up and off the shaft. I also snipped a couple wire ties. The new one installs easily, just make sure the nuts are secure. Replace any wire ties to secure the wires. Within a few cycles of the ignition, the codes were gone and I got my acceleration back!Read full review...
Verified purchase: Yes | Condition: new | Sold by: wPdh13WCQwm@Del...