A4LD (92 Mustang) - No overdrive

Hi and thanks for any help you guys can offer up front.

I just picked up a 2.3 auto 92 Coupe, and it doesn't have overdrive. Vacuum line is good, front sensor is plugged in, VSS is plugged in. I pulled codes and came up with :

566 - 3-4 Shift solenoid circuit failure
629 - Converter clutch solenoid circuit fault or lock-up solenoid circuit failure
223 - DIS - loss of dual plug inhibit (DPI) control

Does it sound like I need a new 2-3 solenoid? If so, can someone point me to the best/cheapest place to get one for my 92?

Thanks
Brandon

In my experience, a KOEO 566 and KOEO 629 represent either a full open in the respective circuit or a short to ground in the respective circuit. Where you have codes for both the 3-4 shift solenoid and the TCC solenoid, I would look first at what these circuits have in common: a common power supply. Make sure the connector is plugged in at the transmission and otherwise check the wiring from the PCM/ EEC relay to the transmission connector.

Sometimes the internal wiring harness in the transmission goes bad.

I'll remove the wiring from the solenoid on top of the tranny tomorrow and clean it up, and the same for the ECU connectors. This is my daily driver, so I'd like to get any possibilities down before I drop the pan and valve body. If it's not the connections, and possibly the 3-4 solenoid, is this what i need :

http://www.bulkpart.com/Merchant2/m...23&Category_Code=A4LDsolenoid&Product_Count=8

It can't be a solenoid since it's showing a code for 2 solenoids that are connected to the same wiring harness.

Thanks. So if internal wiring like you suggested, is there a cure, besides replacing the tranny?

Wanted to add, in order to pull the codes on my scanner, I couldn't just pull them, they wouldn't read. I had to run ground to the ground prong on my wiring harness to the body. Then they read. That makes me think that there is a ground issue somewhere.. Thoughts?

The PCM applies a ground signal to activate the solenoids. No ground signal to the PCM would cause a no start condition, and a lack of stored codes. You could replace the internal connector without having to take the transmission apart or out of the vehicle. Here's a link for the part: http://www.transmissionpartsusa.com/A4LD_Case_connector_3_Prong_1989_94_p/230-00023389b.htm