: Dtc 730

Harry Yarnell
12-01-08, 07:45 PM
'96 Seville SLS. I'm getting a DTC 730; wrong final drive.This car is the one I mentioned months ago that blew up for lack of oil.
Well this powertrain was swapped out of another '96 Seville, may have been an STS, and I think the axle ratios are different between the SLS and the STS. How do I make this code go away?
I MAYBE able to find the ECM the powertrain came with, that swap might work. Any other ideas?

12-01-08, 08:26 PM
The final drive ratios ARE different. SLS = 3.11 STS = 3.71 If you swapped an STS drivetrain into an SLS I think you will have to swap the PCM to make the light go out. Then you'll essentially have an STS in SLS clothing.

Harry Yarnell
12-02-08, 10:25 AM
swapping the PCM doesn't work. At all.The PCM from the donor engine was installed and it won't start. Cranks, but no fire. Can hear the fuel pump run (havn't checked pressure yet), but hitting it with ether; still won't fire.
Methinks there maybe an issue with the new PCM and the Passkey circuit disabling the ignition (havn't checked for spark yet, either).
Is there a removable PROM in the OB2 PCM?

Harry Yarnell
12-02-08, 12:50 PM
UPDATE: Yes, of course there's a PROM. This time I installed the car (SLS) PCM back in the car with the PROM from the STS PCM. Fired right up. Now for a test run....
Apparently the STS PCM is bad. News at 11....

Harry Yarnell
12-02-08, 01:41 PM
Nope. No change. The STS prom in the SLS pcm still gives the DTC 730.

12-02-08, 04:58 PM
Strange. Maybe one of the resident techs will chime in.