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Discussion Starter #1
Trying to get Freescan working with my S4s. I downloaded it from Andy's site, so I believe it is the latest version. It says Esprit 4 cyl on the vehicle list.

I have a USB to serial adapter which uses the Prolific PL2303 chipset. It works fine for me with older aircraft interfaces. I found another thread here where someone said that chipset is known to work. I have it set to COM1 in the control panel, and also on Freescan.

I am not at all sure I have the right plug for the ALDL on the car. Under the passenger side airbag there are two wires that are parked. I believe one of them is for the airbag module, not sure on that. Both fit the Freescan cable I got from Sanj. One is inboard of the module, the other is outboard. I believe the inboard one is correct, which is about in the center of the seat. The other is far to the outboard side, I believe that is the airbag ALDL.

I tried to find the ALDL by the ECU, but I don't see it. I see the ECU itself, the sensor plugged in under the ECU, and the other sensor plugged in up high. This is a late 4 cyl car, so it doesn't have the relay center under the carpet behind the engine. Service manual says the plug is by the ECU but I don't see it.

When I connect Freescan to the under-dash plug that to the inboard side, the Status box has a continuous stream of "Finding start header" messages. I have tried stopping and starting, and force data. The data fields are all blank. mS Delay is at the default 100.

If I connect to the outboard under-dash connector, the Status Message shows "supervisor: com port restarted", which I believe simply means Freescan restarted the monitor. Nothing else happens, so I think that is the wrong ALDL connector.

I tried another laptop using the same hardware and USB adapter. Same result. I don't have a laptop with a built in serial port. I might have one on a desktop computer, but dragging that home and setting it up in the garage is not fun. I may have to do so, but since the Freescan messages are different for the two ALDL connectors, I believe the USB serial adapter is working.

I am trying to check the throttle position sensor voltage. What am I doing wrong?
 

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I don't know if it helps, but I think that the other adapter in there is for the alarm.

Though it would be fun to talk to the airbag... "You ready to blow up?" "Yeah."

;)

The OBDII connection that I have is a straight USB connection. Works fine. So maybe if the serial port is the issue you can get around it completely by going with one of those.

Sorry I can't help more.
 

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Not positive but is there an electrical box in the trunk just inside from the header tank? If so then there should be an ALDL connector in there.
 

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You should also have aplug above the right wheel well near the relay box in the boot. that is one you want for sure. The two in the front are for the engine data, the other for the ? alarm.

Don't have my manual in front of me but the settings need to be correct with the ignition on to see data. the port and the milliseconds have to be correct and then you have to "force data"

Randy
 

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The under-dash plug is often not as reliable as the rear plug. If using the rear plug doesn't work, you may want to try the usb adapter drivers here...Virtual COM Port Drivers.

I had been using Freescan for years with the serial cable, then when I put the usb adapter on the cable, it wouldn't work even with the drivers supplied with the adapter. The drivers from the link I provided fixed it. I don't remember what the technical hangup is (something about baud rates maybe iirc?), but these drivers worked to get around the issue for me. If the rear plug doesn't work, give the drivers a shot.
 

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Discussion Starter #6
Followup on this thread. I used an older desktop computer which has a real serial port. Freescan works fine with that computer. I am using the ALDL under the dash, in the *center* of the footwell. There is an identical ALDL to the outboard side of the footwell, still not sure if that is for alarm or ABS.

As I suspected, Freescan shows my idle air counts are high, about 130. I worked on GM cars when these were new, and we regularly adjusted the base idle to get the idle air counts as low as practical (but not zero). 130 is quite high. Good chance there is some debris built up inside the throttle bodies which reduces the airflow when the plates are closed. I don't have time today to open that up, but I won't be surprised later if the base idle needs to be adjusted.

I still have not found the rear ALDL. I looked by the ECU, over the right wheelhouse, and around the battery. This is an S4s, so it does not have the relay center at the front of the boot. If someone has an S4s (probably the same on S4), please give me a hint!
 
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