Ford Workshop Service and Repair Manuals

KOEO Memory Code .............................................................................................................................................................................  Go to X105
See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Pinpoint Tests/X - Constant Control Relay Module
(CCRM)/X105 - Continuous Code 542: Check EEC-IV Harness

DTC 543

Fuel pump secondary circuit failure.

KOEO Hard Code .....................................................................................................................................................................................  Go to X90
See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Pinpoint Tests/X - Constant Control Relay Module
(CCRM)/X90 - Does Engine Start

KOEO Memory Code .............................................................................................................................................................................  Go to X110
See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Pinpoint Tests/X - Constant Control Relay Module
(CCRM)/X110 - Check for DTC 556/557

DTC 551

Idle Air Control circuit failure during KOEO self-test.

KOEO Hard Code ....................................................................................................................................................................................  Go to KT1

DTC 552

Secondary Air Injection Bypass circuit failure during KOEO self-test.

KOEO Hard Code ....................................................................................................................................................................................  Go to KC9
See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Pinpoint Tests/KC - Secondary Air Injection
Solenoids/KC9 - Check Voltage of VPWR Circuit

DTC 553

Secondary Air Injection Diverter circuit failure during KOEO self-test.

KOEO Hard Code ....................................................................................................................................................................................  Go to KC9
See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Pinpoint Tests/KC - Secondary Air Injection
Solenoids/KC9 - Check Voltage of VPWR Circuit

DTC 554

Fuel Pressure Regulator Control circuit failure.

KOEO Hard Code ....................................................................................................................................................................................  Go to KN1
See: Powertrain Management/Computers and Control Systems/Testing and Inspection/Pinpoint Tests/KN - Fuel Pressure Regulator Control
Solenoid/KN1 - DTC 554, Enter Output State Diagnostic Test Mode