TC - Testing Notes

NOTE: You should enter this Pinpoint Test only when you have been directed here from Quick Test.


REMEMBER

This Pinpoint Test is not intended to diagnose components interior to the transmission. To prevent the replacement of good components, be aware that the following non-EEC areas may be at fault.


- Engine

Performance, vacuum, cooling

- Brakes

Not fully releasing

- Electrical

Alternator, battery, integrity

- Transmission

Hydraulic fluid, friction elements, cooling


This Pinpoint Test is intended to diagnose only the following:


- Harness circuits: M/CCC, CCO, CCS, EPC, SS3/4-4/3 SS1, SS2, SS3, SIG RTN, EPC PWR, and VPWR

- Processor assembly



DESCRIPTION


The 4EAT transmission uses three solenoids for shifting and one for the converter clutch operation. The solenoids are controlled by the EEC-IV processor. While other Ford transmission solenoids are controlled by a "ground" signal from the processor, these 4EAT solenoids are controlled by a positive voltage ("high side") output from the processor.