Fault Memory Display Overview

A/C CONTROL HEAD MEMORY DISPLAY

Starting Display:
- Switch ignition ON.
- Push and hold down Outside Temp button.
- Push and hold down OFF button.
- Release Outside Temp button then Off button.





- A vertical line in the first field (see arrow) lights up to indicate the channel number.

To Select a Different Channel:
- Press Warmer button to advance channel by one.
- Press Cooler button to decrease channel by one.

To Call up Information About a Particular Channel:
- Select desired channel.
- Press Outside Temp button.

To Leave the Memory Display:
- Select any A/C operating mode, or switch ignition to OFF.





- Some faults are displayed without having to start the memory fault process. If a problem develops that affects temperature regulation, the ambient temperature light (see arrow) will flash for about one minute each time the ignition is switched ON or when the fault first occurred. The following faults will cause the ambient temperature light to flash:
^ One or both inside temperature sensors is transmitting incorrect values.
^ Both outside temperature sensors are transmitting incorrect values.
^ The feedback potentiometer on the temperature regulating flap is supplying incorrect values or the adjusting motor is not properly adjusted.
^ The A/C refrigerant high pressure switch F118 (red housing) has switched the A/C compressor OFF eight times in the last driving period. This fault may be erased by depressing the OFF button or by cycling ignition switch.





- Up to August 1988, twenty one diagnostic channels were available for information output on the control head display. From August 1988, twenty two channels were used. For diagnostic values greater than 199, the first digit 2 is represented as a horizontal and a vertical line. For example, 255 is shown on image.

- While information is being displayed on the A/C control head, the A/C system will run in the last selected mode.