2004 XC90 AW55-50SN P0740 question about symptoms

dadyer · Post by **dadyer** » 25 Jan 2016, 09:00

Transmission Service Required message came on with CEL. Code read was P0740.
The car accelerates fine at start up when engine is cold. After 3 or 4 miles, goes into limp mode (D changes to dash), cruise control stops working, and starting from a dead stop feels like it is trying to take off from 2nd or 3rd gear instead of 1st. Otherwise, transmission seems to be working fine.
I'm thinking replacing the three linear solenoids with new ones from Rostra might fix this? Can these be replaced without pulling the transmission or removing the valve body?
Any suggestions and comments appreciated!

Post by **oragex** » 26 Jan 2016, 13:58

Given the cruise control stops working at same moment, I would try to figure out if there's some other main computer anomaly that can cause all the issues. When the solenoids work less well, the transmission will still be shifting through the gears, just a little more harsh.

Is the Winter mode on (button near the shifter)? It will appear as W on the display in place of a D. Maybe liquid causes the W button to stick/short

The 2004 models had an issue with corrosion at the main Eco unit under the hood - there are two modules inside a black box near the power steering reservoir, worth a look

dadyer · Post by **dadyer** » 28 Jan 2016, 13:54

Thanks, I'll check those out.