S52, all new OBD1 sensors with Treehouse adapter, 413 Red label with TRM chip, 91 octane, 3.5 HFM, LW flywheel, headers in an 88 325is. Been driving it since October with no CEL. Just had new vanos unit installed by certified BMW garage. CEL comes on, Code 45 rear knock sensor.
Stock ECU no CEL's even after driving in the mountains and on freeway for 2 hours. Power seemed ok and it took a couple of trys to start when hot, but otherwise it ran fine.
Swapped in the replacement TRM chip (LW flywheel, 3.5 HFM, 21.5# injectors, 7K redline)
Started up the car and the CEL comes on. Checked it Code 45, rear knock sensor. Drove car for an hour, various speeds, ran 2 3rd gear WOT pulls from 50mph, would hit what felt like a soft rev limiter at 6200-6300, hit 4th gear, ran up to approx 105mph before shutting down. Seems to run just fine, except for the low rev limit. I have had it up to close to 7K before, so I don't know why it's down to 6200.
Checked codes again, code 45, rear knock sensor AND Vehicle Speed sensor.
This is the 2nd chip from TRM, 1st one did the same thing (Code 45).
Hadn't had the car up that fast so the Speed Sensor code is the first time that has come up.
I've checked everything I can think of, and a few things TRM suggested. BMW shop hasn't run into this before and they do swaps themselves.
Odd that the stock chip works OK but the performance chip has the Code 45 only and not both knock sensors.
Checked the Crank sensor resistance and it reads 630, while the Bentley says it should be 1280. Might have to break down and buy a new crank sensor or at least test one to see if it's the same...
OK checked a new crank sensor and it reads 580, so it's within the spec according to the Bentley.
Why would the CEL come on at 1800rpm, and not right at startup?
Stock ECU no CEL's even after driving in the mountains and on freeway for 2 hours. Power seemed ok and it took a couple of trys to start when hot, but otherwise it ran fine.
Swapped in the replacement TRM chip (LW flywheel, 3.5 HFM, 21.5# injectors, 7K redline)
Started up the car and the CEL comes on. Checked it Code 45, rear knock sensor. Drove car for an hour, various speeds, ran 2 3rd gear WOT pulls from 50mph, would hit what felt like a soft rev limiter at 6200-6300, hit 4th gear, ran up to approx 105mph before shutting down. Seems to run just fine, except for the low rev limit. I have had it up to close to 7K before, so I don't know why it's down to 6200.
Checked codes again, code 45, rear knock sensor AND Vehicle Speed sensor.
This is the 2nd chip from TRM, 1st one did the same thing (Code 45).
Hadn't had the car up that fast so the Speed Sensor code is the first time that has come up.
I've checked everything I can think of, and a few things TRM suggested. BMW shop hasn't run into this before and they do swaps themselves.
Odd that the stock chip works OK but the performance chip has the Code 45 only and not both knock sensors.
Checked the Crank sensor resistance and it reads 630, while the Bentley says it should be 1280. Might have to break down and buy a new crank sensor or at least test one to see if it's the same...
OK checked a new crank sensor and it reads 580, so it's within the spec according to the Bentley.
Why would the CEL come on at 1800rpm, and not right at startup?