Do New Crank Sensors Require Scan Tool To Relearn?

[turboguy]

For those of you who have changed crank sensors, is a scan tool mandatory for a classic 99 Aurora to relearn the crank sensor signals?
Or will it relearn automatically by itself?

Some searching showed me that some thought it was needed, some thought it wasn't.

[sall]

Not on a Classic AFAIK. Mine didn't.

[bobsblue95]

No. It's a simple hall-effect sensor and the PCM should recognize it immediately. Hall-effect sensors have no moving parts and are EXTREMELY UNLIKELY to actually fail. More likely a bad wire or connection between the sensor and PCM. Are you getting a code for crank sensors or what?

[turboguy]

Hmmm. Yeah, I have these codes:
741 TCC Circuit Performance or stuck off
1375 24X reference circuit high voltage
1377 Cam to reference correlation

Bad crank sensors or wiring etc problems?

[bobsblue95]

None of those would indicate a crank sensor problem...
Maybe a bad ground to the ICM?
Torque Converter Clutch... inspect the transmission connector and wiring.

[sall]

Sept 21, 2013 16:39:13 GMT -6 bobsblue95 said:

No. It's a simple hall-effect sensor and the PCM should recognize it immediately. Hall-effect sensors have no moving parts and are EXTREMELY UNLIKELY to actually fail. More likely a bad wire or connection between the sensor and PCM. Are you getting a code for crank sensors or what?

2G crank sensors often require re-learn. They are hall effect sensors too. Hall effect sensors do fail. Quite common failures. CKPS, Cam sensor, VSS, Wheel speed sensors, etc and so forth. Not saying they aren't reliable though.

GM especially had problems with bad CKPS on 00-01 Auroras and Caddys IRRC.

I agree though check your ground to ICM and all four connectors.

[RCA1186]

The 24X high voltage code CAN indicate Crank sensors. Have you done any work to the A/c compressor or the oil sensors? The crank sensor can come unplugged pretty easily. Ask me how I know haha. I got that same code, car would run, but you had to crank it a good couple seconds for it to start.

[sall]

Sept 23, 2013 10:07:59 GMT -6 RCA1186 said:

The 24X high voltage code CAN indicate Crank sensors. Have you done any work to the A/c compressor or the oil sensors? The crank sensor can come unplugged pretty easily. Ask me how I know haha. I got that same code, car would run, but you had to crank it a good couple seconds for it to start.

Sure your connector(s) aren't broken? They have the silicone insulator and the locking tab. Shouldn't pull out even with force.

Having both 24x and Cam Sensor code lead me to believe ICM(ground, connections or internal fault) or PCM issue though.

[bobsblue95]

Sept 23, 2013 13:24:14 GMT -6 sall said:

Sept 23, 2013 10:07:59 GMT -6 RCA1186 said:

The 24X high voltage code CAN indicate Crank sensors. Have you done any work to the A/c compressor or the oil sensors? The crank sensor can come unplugged pretty easily. Ask me how I know haha. I got that same code, car would run, but you had to crank it a good couple seconds for it to start.

Sure your connector(s) aren't broken? They have the silicone insulator and the locking tab. Shouldn't pull out even with force.

Having both 24x and Cam Sensor code lead me to believe ICM(ground, connections or internal fault) or PCM issue though.

+1 on both counts

Also, the more I read about them, the less I like about the 2G, electronics-wise.

[randnon]

Sept 23, 2013 10:07:59 GMT -6 RCA1186 said:

The 24X high voltage code CAN indicate Crank sensors. Have you done any work to the A/c compressor or the oil sensors? The crank sensor can come unplugged pretty easily. Ask me how I know haha. I got that same code, car would run, but you had to crank it a good couple seconds for it to start.

Wow, I want to thank Rob for this post as it is exactly what happened to me yesterday. I changed my AC pump and thought everything was back together properly and bamb code 1350 and 1375. Changed the ECM and ICM with good used spares I had on the shelf from the pick and pull and no luck. Being frustrated I went to the club and bingo one of the crank sensors had come unplugged when I move some wires.

My 99 has a different front engine mount and it took me 30 minutes to get that plug back in . It is very hidden and I could not get in there oven with my small hands. I think changing the crank sensors would involve removing that mount. You cant even get a view of the lower sensor from any angle. If someone has change these on a 99 and has some hints please let me know the proper way. Rich In Buffalo.

[RCA1186]

Mar 23, 2021 5:59:36 GMT -6 randnon said:

Sept 23, 2013 10:07:59 GMT -6 RCA1186 said:

The 24X high voltage code CAN indicate Crank sensors. Have you done any work to the A/c compressor or the oil sensors? The crank sensor can come unplugged pretty easily. Ask me how I know haha. I got that same code, car would run, but you had to crank it a good couple seconds for it to start.

Wow, I want to thank Rob for this post as it is exactly what happened to me yesterday. I changed my AC pump and thought everything was back together properly and bamb code 1350 and 1375. Changed the ECM and ICM with good used spares I had on the shelf from the pick and pull and no luck. Being frustrated I went to the club and bingo one of the crank sensors had come unplugged when I move some wires.

My 99 has a different front engine mount and it took me 30 minutes to get that plug back in . It is very hidden and I could not get in there oven with my small hands. I think changing the crank sensors would involve removing that mount. You cant even get a view of the lower sensor from any angle. If someone has change these on a 99 and has some hints please let me know the proper way. Rich In Buffalo.

Glad I could help. It happened to me on my 99 as well, I ended up getting it plugged in with a long flathead screwdriver (it really is impossible to reach in there!)