Automatic Temperature Control - Code 10 Diagnosis
84ford16Article No. 84-6-3
AIR CONDITIONING - ELECTRONIC - AUTOMATIC TEMPERATURE CONTROL - CODE 10 APPEARS ALONE DURING DIAGNOSIS
LINCOLN-MERCURY 1984 MARK VII, CONTINENTAL
When performing a diagnostic self test, there is a possibility that a Code 10 may appear alone (no codes appearing before or after the Code 10) on the control assembly display. A Code 10 appearing alone is not defined in the self test error codes.
Procedure
If a Code 10 appears in the absence of all other codes, this indicates no failures were found by the self test. In this case, the Code 10 is defined the same as Code 88 (no failures found). If a Code 10 and 11 appear, refer to the self test error codes in the 1984 shop manual section 36-75. If a Code 10 appears with codes other than Code 11, ignore the Code 10 and refer to the self test error codes in section 36-75 for the definition of the remaining error codes.
Self Test System Procedure
The control head has a self test feature that aids in locating trouble in the EATC system. To get reliable results, the following procedure must be followed. Turn on the ignition and set the control head to 90, OFF. Wait 40 seconds. If the vacuum fluorescent display (VFD) begins to flash, then there is a malfunction in the blend actuator wiring, the actuator itself, or the control head. If the light emitting diode (LED) begins to flash, then there is a malfunction in one or more of the other actuators' wiring, the actuator (mode, PAN/DEF, or FA/REC) or the control assembly. If no flashing occurs, set the control assembly to 60, DEF. Wait 40 seconds, look for a flashing VFD or LED. If no flashing occurs, then no malfunctions in the actuator drive or feedback circuits have been detected. Whether or not flashing has occurred, the self test mode should now be entered for further diagnostic information. To ensure accurate self test results, the above procedure must be followed before entering the self test mode.
To enter the self test mode, push the OFF and DEFROST mode buttons simultaneously. Within two seconds, push the AUTO mode button. If an 88 is displayed, no malfunctions have been detected by the control
assembly. If a control assembly malfunction has occurred, the appropriate error code or codes will be displayed. Refer to Self Test -- Error Code. The error code sequence will continue until the cooler button is pushed. When the cooler button is pushed, the system will revert to the AUTO mode at a temperature setting one less than the setting before entering the self test mode. Always exit the self test mode by pushing the cooler button before turning off the ignition. This procedure will ensure the proper resetting of the control assembly when the ignition is turned on.
The above procedure can be found in Volume B, section 36-75 of the 1984 Shop Manuals. Symptom diagnosis and self test error codes can also be found in this section. Be certain when performing the above procedures to allow for proper stabilization times, as this will help to ensure accurate error codes.
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