99 XC70 TCU maybe?

Post by **erikv11** » 06 Nov 2014, 17:30

A 99 XC is for sale around the corner from me, the seller's ad says

"Contains Fault in the Internal Control Module - will need repaired by you or dealership.
Car drives but starts in 3rd Gear."

I know this could be a number of things and I have to get more info but just an upfront question: Is the TCM on these cars interchangeable, or a married hassle like the ECM?

Any thoughts on what to look for are welcome, like how to know if this too much of a can of worms to bother with?

Post by **Matty Moo** » 06 Nov 2014, 17:37

Grab or borrow a scanner and go look at it. That code description is entirely too vague and could apply to several different things.

Post by **Matty Moo** » 06 Nov 2014, 17:41

I've never seen a "control module-internal fault" code out of anything but an abs module.

Post by **erikv11** » 06 Nov 2014, 17:54

Would an ABS module fault cause it to be stuck in 3rd?

My Autel EU102 should get the codes I need right?

Post by **Matty Moo** » 06 Nov 2014, 18:04

Depends on exactly what the internal fault is. I have 5 of them here with that code and two of them won't communicate with the tcu thus causing limp mode. Internal fault can mean a blown capacitor, blown chipset or a software issue. Your eu702 will read the the trans and abs codes on that car.

Post by **Matty Moo** » 06 Nov 2014, 18:05

Also, when scanning the car enter the info as a 2000,if you enter 1999 it won't give you the option to scan the tcu

Post by **erikv11** » 06 Nov 2014, 18:33

Great info, thanks Matt.

Post by **precopster** » 07 Nov 2014, 01:19

ICM is not used in this MY. That is a module in P3 cars (XC90) and is located near the Audio module as a passthrough for data.

TCM is married to car and can be cloned on Bosch system cars if the TCM sw version can be read. The Autel EU 702 can do this using the method Matty stated.

Post by **abscate** » 07 Nov 2014, 04:54

I think Timmy in AZ put it best. If they tell you the "computer" is the problem, they don't have a clue.

Post by **precopster** » 07 Nov 2014, 05:15

Could very well be a simple solenoid failure in the valve body or PNP problem or a TCM that hasn't been removed for cleaning (99s require the tool for TCM/ECM removal)

Only after reading with Vida Dice would a true diagnostic be apparent. There are several tests that Vida can perform such as individual solenoid actuation and resistance of individual solenoids in the transmission. It can even tell you which gear is selected by the PNP.

I would take it on as a love job for extremely low dollars because in the end it may well need a transmission.