Looking for any insight anyone has, have a 2010 suburban 5.3 and the tachometer doesn't work. I already replaced the crank sensor with an oem unit. Wiring was undamaged. The gauge sweeps at startup so I believe the gauge is fine. Truck also has no acceleration but is fine once youre going and shifts hard out of first. Ive seen a couple threads here where people had the same issue but never saw a fix. Any help would be greatly appreciated!

 

can you scan for any codes? can you read live data on your scanner if you have one? what does it say the rpms are?

the tach gets its signal from the pcm. so the sensor could be sending the right signal but the pcm is screwing up and reading it wrong and that could be whats causing your loss of power also.

 

I will have to see if my scan tool has live data, that's a good idea. Before changing the sensor there was a code, after no cel was present, drove it about 10 miles dont know if that was long enough to set any. I disconnected the battery to change the sensor so that cleared any codes I'm sure.