Test "L" (Display Does Not Switch Between FAHRENHEIT & CELSIUS)

WARNING: This page is about a different car, the 1996 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.

Check EATC System

Test EATC system operation. See EATC SYSTEM TEST under TESTING. Repair as necessary. If system tests okay, go to next step.

Check °F To °C Display In Display Window

Turn EATC system on. Simultaneously press MAX A/C and DEF buttons for at least 3/4 second. If display switches from °F to °C, go to next step. If display does not switch from °F to °C, replace EATC module (control panel).
CAUTION: In following steps, grounding any terminal other than Red wire terminal may damage EATC module.

Check For Short To Ground In Red Wire

Turn ignition off. Disconnect right EATC module connector from back of control panel. Disconnect connector C2 from instrument panel. Measure resistance between known-good ground and terminal No. 20 (Red wire) of EATC module connector. If resistance is 10,000 ohms or more, go to next step. If resistance is less than 10,000 ohms, repair Red wire for short to ground.

Check Continuity Of Red Wire

Turn ignition off. Measure resistance of Red wire between EATC module connector and instrument cluster connector C2. If resistance is 5 ohms or less, go to next step. If resistance is more than 5 ohms, repair open Red wire.

Check EATC Module (Control Panel)

Turn ignition off. Reconnect EATC module connector. Connect jumper wire between known-good ground and terminal No. 20 (Red wire) of EATC module. Turn ignition on. If display does not change, replace EATC module (control panel). If display changes, service digital instrument cluster (message center indicator). See the INSTRUMENT PANEL article in the ACCESSORIES/SAFETY EQUIPMENT section.