Hello, i recently purchased a 2008 FX4 with a bad engine. Replaced the engine and now it runs good. I tried to engage the 4x4 system but all is dead. I checked the valve behind the battery it works but is not turned on. I removed the transfer case motor to test it, The motor works but not with the switch. The dash lights also don't turn on. Checked the wiring on the switch and all seems well. Also tried operating the motor at the motor relays and it works. Also tried reading the 4x4 ECU but no response. My Launch X431 Master gets to all ECU's but not the 4x4. For now i have put it manually in 2WD and bypassed the valve behind the battery. Checked the 4 fuses in the fuse box and all good. When reading the ECM i get fault code P1000 On-board diagnostic (OBD) systems readiness test not complete. Any light on this matter will be greatly appreciated

 

no help on the 4x4 system
but the p1000 code is nothing, just hasn't been driven enough to complete the test.

I'm sure somebody will be along to help with the 4x4

 

 

I looked in both fuse boxes. The one on the passenger side and thge one behind the left front light. I measured the resistance between the 2 bleu wires on the SOFT switch which measure good. I was thinking that when i bought the car i noticed that several fuses were bridged with wires. I have found a wiring diagram for the ECM. I will check all power wires to see if power gets to the ECU 4x4 part. will be continued

 

 

The problem is fixed. Changed the ECU and i could enter the 4x4 module. When turning on the ignition the 4x4 light on the dash light up. Thank you for your help