2007 Ford Five Hundred 3.0L Duratec/Aisin F21, Complaint of no A/C. This car aggravated me a little
![Mad :mad: :mad:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
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Started with jumping the A/C clutch relay.....A/C blows cold with some water across the condenser. Normal operation as the ECM ignores head pressure unless there's an A/C request sent to the ECM (Fans will not come on the relieve head pressure), Screwy engineering....But it is what it is.
Hooked up the scan tool & sure enough....No A/C Request being received. This car has manual A/C, So the control head sends a ground to the Instrument Cluster (IC), The IC then sends a A/C Request to the ECM via the High Speed CAN Bus.
Check for the ground from A/C control head & it checked good....Even checked at the circuit board to rule out connection issues at the IC connector.
The Ford trouble tree specifically states to correct any DTC's present in the ECM & IC......The IC had a U1900 & U1901 which basically means there are missing modules.....This car has a aftermarket radio & the Airbag Module seems to be dead. So I ignored these DTC's as all the other modules would communicate.
Went through the trouble tree & at the end it said replace & program the ECM, I've been doing this long enough to not fall for that one!!
This video helped steer me in the right direction, Even though I didn't have a B2477 Module Configuration Error DTC....The IC DID have wreaking yard paint pin scribbles all over the back.
Fired up the old Forscan & programmed the IC to "as built", A/C now works! But I still have a U1900 & U1901 because the Radio & Airbag Module.
My theory is the IC was from a car with Electronic A/C & didn't recognize the analog input from the Manual A/C control head. I'm sure the missing message from a Electronic A/C control head was one of the reasons for U1900/U1901 DTC's.
Another theory is.....If this was the other way around, The car had Electronic A/C with a IC for Manual A/C.....The IC would think why is this module on the line when it shouldn't be & set a B2477??
Here's the video, I'm not one to rely on the internet to repair vehicles, But there are times when you need a push in the right direction.
Then I got back to a 2002 Express 4L60E build.....Just a base build....I'll finish it up in the morning.
*Vette 2nd Servo
*Blocked & gutted 4th Accumulator
*Hardened GM sun shell
*7 Borg Warner high energy 3-4 frictions using 4L65E Apply & Backing Plates
*Borg Warner double cage forward sprag
*TransGo SK shift kit
*TransGo hardened spacer plate
*Sonnax .490" boost valve
*Sonnax 2-4 Band apply pin
*Durabond bushings throughout, Endplay & clutch clearances blueprinted