MY EFX SAYS ERROR 30 WHAT WRONG WITH IT

Errors 30 through 33 all indicate the loss of communications or erratic communications betweenthe microprocessors in the upper PCA and the lower PCA. The trouble shooting procedures forall of the are essentially the same. Error 30 is defined as upper PCA not receiving from lowerPCA. Error 31 is defined as faulty data received from lower PCA. Error 32 is defined as lowerPCA not receiving from upper PCA. Error 33 is defined as faulty data received from upper PCAPossible Causes1. An upper PCA to lower PCA interconnect cable is bad.2. The interconnect cable at the upper PCA was mistakenly plugged into the CSAFE connector.3. A 5.17 EFX equipped with version 1.01 upper and lower software.4. A 5.17 with mismatched upper and lower software.5. A defective lower PCA.6. A defective upper PCA.Possible Remedies1. Substitute a know good interconnect cable between the upper and lower PCAs to determineif the interconnect cable is defective.2. Remove the interconnect cable from the CSAFE connector and insert it in the correct upperPCA connector.3. Replace the 5.17 upper and lower software with the most current software versions.4. If only one of the upper or lower software is version 1.01, replace the version 1.01 softwarewith the most current version of software.5. Substitute a known good lower PCA to determine if the lower PCA is defective.6. Substitute a known good upper PCA determine if the upper PCAs defective.