Code: P0502 (from auto zone obd II scanner)
Symptoms: Dead speedometer, rpm not passing 4500 rpm (limp mode), radiator fan constantly running.

I took the car to a dealership and they said it's ECM logic issue :confused:
The service rep said they checked the speed sensor and it is okay. The service statement said they my car has down pipe and ECM logic has been changed. Therefore, it's not warrantable.

Is this another dealership BS or something wrong with my AP?

...what else did ya (try to) install????


....and this has absolutly nothing, directly, to do with the dp....unless ya broke a wire doin the install.

...what else did ya (try to) install????


....and this has absolutly nothing, directly, to do with the dp....unless ya broke a wire doin the install.

I've been running cobb stg 2 for a while w/o any issues. It just happened all of a sudden. I'm still getting P0502 and dealer is saying the speed sensor is fine. Is it really my ecu? or they did not really checked the sensor?

...well...here ya go......


http://img.photobucket.com/albums/v113/unclescotty/p0502-01.jpg


http://img.photobucket.com/albums/v113/unclescotty/p0502-02.jpg


or they did not really checked the sensor?

...sounds to me like they are seeing a dp and stopping to blame that.

bull****

^Thank you for the information.

I got this response from regional forum:

If the speed sensor is working and the speedometer registers speed when it is spun, then the drive gear inside the transmission (I'm assuming you have a manual trans) is stripped. That could IN NO WAY be caused by modifiying your car, unless your transmission has been disassembled. I'm not saying that is is common, *cough* yes it is *cough* but we have heard of it at Saab...

Oh, and the ECM has absolutely NO control over speedometer function on your car. (again, this only applies to a manual transmission car) There is a direct wire from the speed sensor that branches to the ECM, speedometer, and the cruise control module. If you took the ECM out and threw it away, and towed the car at 50mph with the key on, the speedometer will still read 50mph.


I have to take the car to another dealer. Hopefully, they fix it under warranty w/o any BS.

GD(H$DOTC)-155, it mentions about Fail Safe.
What does it mean? Is this some kind of safety feature associated with P0502 DTC?


Throttle position sensor signal process: All closed points learning / Not allowed to increase.

Vehicle speed sensor signal process: Vehicle speed=0 km/h (0 MPH).


Fuel cut control: Vehicle speed = 0 km/h (0 MPH)/ Not allowed to carry out the fuel cut. High vehicle speed/Not allowed to carry out the fuel cut.


ISC open loop compensation: Fix the open loop compensation at 5%.


ISC feedback control: Not allowed to calculate the amount of ISC feedback


Air conditioner control: Not allowed to resume the air conditioner that is cut with the throttle fully opened.


Radiator fan control: Both main and sub fan are in High driving

this may sound stupid, but have you disconnected your negative battery term to clear out the computer? While I doubt it would solve any serious issues, im not fimilar with this one, I would try that. Also look and see if Cobb has any newer version of the Stg2 map your running and upload that.

Simple troubleshooting i'd start with.

this may sound stupid, but have you disconnected your negative battery term to clear out the computer? While I doubt it would solve any serious issues, im not fimilar with this one, I would try that. Also look and see if Cobb has any newer version of the Stg2 map your running and upload that.

Simple troubleshooting i'd start with.

I believe I have the latest version of stg 2 map.

Thanks anyway.

....did ya disconnect the green plugs under the dash after ya flashed it????

....did ya disconnect the green plugs under the dash after ya flashed it????

It's been disconnected for almost a year.
Do you know anything about the Fail Safe listed above?
Are they safe feature associated with DTC P0502?
My radiator fan is running constantly as well as limp mode when I get CEL.

It's been disconnected for almost a year.
Do you know anything about the Fail Safe listed above?
Are they safe feature associated with DTC P0502?
My radiator fan is running constantly as well as limp mode when I get CEL.

:rolleyes:

.....d00000000d......do ya understand that ya got a borked car???

one of the symptoms of what is wrong is the ****ing 'limp mode'.

ya fix the problem the ****ing 'limp mode' goes away.


jesus....ya REALLY need to come to terms with these issues.


There is NOTHING AT ALL, to me, ambiguous with the service manual and what it says.

:rolleyes:

.....d00000000d......do ya understand that ya got a borked car???

one of the symptoms of what is wrong is the ****ing 'limp mode'.

ya fix the problem the ****ing 'limp mode' goes away.


jesus....ya REALLY need to come to terms with these issues.


There is NOTHING AT ALL, to me, ambiguous with the service manual and what it says.

:huh:

Why do you think I'm posting here for?
I'm trying to gather information about my problems.
Can you tell what the problem is?
I'm having a hard time following your comments :rolleyes:

Have you or someone you know come across the same problem? How did you fix the problem?

I have done this repair numerous times. You need a speedo drive gear. Little orange gear on the end of the speed sensor. Changed bunches under waranty.

I have done this repair numerous times. You need a speedo drive gear. Little orange gear on the end of the speed sensor. Changed bunches under waranty.

Hopefully, they can nail it to that speedometer gear.
The first dealer could not even get to that point and called off the service, blaming ECM logic :furious:
It the ECM is corrupted, it should not even throw DTC code P0502.


Thank you!

I took my car to a second dealer and they thought it was speed sensor. They were willing to replace it under warranty. I waited for about 2 weeks for the part and turned out to be it wasn't the sensor. The problem was speedometer gear inside the tranny. At this point, they would not repair it under warranty since I have modifications. I called SOA complained and SOA approved the repair under warranty. :rolleyes: It's not done yet. The dealer is waiting for the part, speedometer gear this time.