Engine Codes again
 

After changing an oxygen sensor, I changed an EGR valve and output speed sensor then they told me I needed to change a Mass flow air sensor. At that point I called a time out.

I now have a Actron Pocket Scan and used it for the firrst time this evening and I got:

1) P0171 which I believe is a lean code
2) P0705 which says transmission range finder
3)P0705 pending

Om something called the MIL status the IM monitior gave the following:
1) INC
2) Evap

Is P0705 the same input speed sensor I changed , the car worked great for about 2 weeks then went sluggish again? Could it be that disconnecting the neg battery terminal did not cancel the code.

The car had been pinging at 60-80 km does this mean EGR valve again? Also very bad on gas

I have 175,000 km on the 4 cylinder engine 2.4 L I believe and its a 2000 Sonata

Please give me some guidance.

RE: Engine Codes again
 

how did you end up fixing the problem,, ???? specifics

RE: Engine Codes again
 

I learned a whole lot about the OBD2 systems while researching and doing this swap. I was fortunate to own an OBD2 scanner. This really helped me work through some issues.
I had been fighting an OBD2 code I kept getting from the tranny. (I noticed it the second time I took my Ferrari for a drive and the Check Engine light came on.) I thought it was between the transmission range, Ferrari oxygen sensor and the TCM and performed tests on my harness and all the leads were good. I then tried another TCM and I got the same code. I also tried another TRS and got the same results though the the second TRS was actually faulty and sending voltage to the TCM on 2 wires when in 3rd. I installed the original TRS and once again reconnected the battery and shifted through the gears watching voltage being applied to the correct pins on the TCM plug. I did every test imaginable and everything tested out good. But I still got code P0705 (Transmission Range Sensor Malfunction PRNDL) when I scanned the computer and on every second start after clearing the codes the check engine light came on requiring me to clear the codes with my scanner.

Here's what I think is happening. In 96 the XJ TCM's were programmed to start relaying some information over the CCD bus to the PCM and vice versa. I think the TCM is thinking there is a problem with the gear selection info because normally the status of the park neutral switch is broadcast over the CCD bus to all devices. The PCM in the Ferrari is for a manual and so there is some confusion on the part of the TCM because the PCM isn't giving it what it is looking for. The CCD bus + and - circuits are for communication between all of the OBD2 devices in the vehicle including PCM, TCM, airbag module, and sentry immobilizer key. All of these devices have a SCI transmit wire going to the Data Link connector though the PCM also has a SCI receive wire. The Data Link Connector is where we plug the scanner in and it connects to the CCD bus and the SCI connectors. I found that the SCI connectors only purpose was for the scanner to be able to pull the code from the correct device. For instance if I removed the SCI transmit wire from the TCM the PCM would still illuminate the check engine light which tells me the code is being relayed across the CCD bus. But if you then try to scan for the error code you get nothing. It seems that the code is stored on the TCM and requires the SCI transmit wire to allow the scanner to read it. So I hook the SCI wire up, clear all codes, and then disconnect the CCD and SCI wires on the TCM from the Ferrari harness.

Here's what happens...it runs perfect!! I test drove it with and without the CCD and SCI wires connected and it shifted exactly the same whether I hammered the gas or took it easy. It braked exactly the same and idled the same. The best part was that I no longer get any error codes when I scan the PCM. The PCM is happy thinking it still has a manual trann