Test K: One Or More Steering Wheel Control Switches Is Inoperative

WARNING: This page is about a different car, the 1999 Lincoln Navigator and 1999 Ford Expedition. However, it is still accessible from the selected car via links, so may be relevant.

Check Input To EATC

Turn ignition off. Disconnect EATC harness connector (C281). Using ohmmeter, measure resistance of Brown/Light Blue wire between module connector and ground. If resistance is between 1500-5000 ohms, go to next step. If resistance is not between 4500-5000 ohms, go to step 3) .

Check Steering Wheel Control Switch Output

Measure resistance of Brown/Light Blue wire between EATC module connector and ground, while pressing each steering wheel control switch button. Compare readings with STEERING WHEEL SWITCH RESISTANCE SPECIFICATIONS table. If readings are within range, replace EATC module. Retest system. If readings are not within specification, replace steering wheel switch assembly.

STEERING WHEEL SWITCH RESISTANCE SPECIFICATIONS

Switch Position	Resistance (Ohms)
Temp Up	336-375
Temp Down	1620-1810
Fan Up	736-821
Fan Down	123-138

Check System For Open

Measure resistance of Brown/Light Blue wire between EATC module connector and ground. If resistance is less than 4500 ohms, go to next step. If resistance is more than 4500 ohms, go to step 7) .

Check For Short To Ground

Measure resistance of Brown/Light Blue wire between EATC module connector and ground. If resistance is less than 10,000 ohms, repair short to ground in Brown/Light Blue wire. If resistance is more than 10,000 ohms, go to next step.

Check Steering Wheel Switch For Short To Ground

Disconnect steering wheel control switch harness connector. Measure resistance of Light Blue/Red wire between switch connector and ground. If resistance is less than 10,000 ohms, go to next step. If resistance is more than 10,000 ohms, replace steering wheel switch module. Retest system.

Check Steering Wheel Switch In-Line Connector For Short To Ground

Disconnect steering wheel switch in-line harness connector. Measure resistance of Light Blue/Red wire between switch in-line connector and ground. If resistance is less than 10,000 ohms, repair steering wheel switch harness. If resistance is more than 10,000 ohms, replace air bag sliding contact assembly. Retest system.

Check Ground Supply To Steering Wheel Switches

Disconnect air bag sliding contact harness connector. Measure resistance of Dark Green/Orange wire between sliding contact connector and ground. If resistance is less than 5 ohms, go to step 9) . If resistance is more than 5 ohms, go to next step.

Check Dark Green/Orange Wire Circuit For Open

Disconnect speed control servo module harness connector. Measure resistance of Dark Green/Orange wire between air bag sliding contact connector and speed control module connector. If resistance is less than 5 ohms, replace speed control module. Retest system. If resistance is more than 5 ohms, repair open in Dark Green/Orange wire. Retest system.

Check Brown/Light Green Wire Circuit For Open

Measure resistance of Brown/Light Green wire between air bag sliding contact connector and EATC module connector. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open in Brown/Light Blue wire. Retest system.

Check Steering Wheel Switch For Open

Disconnect steering wheel switch harness connector. Measure resistance of Light Blue/Red wire between air bag sliding contact connector and steering wheel switch connector. If resistance is less than 5 ohms, replace steering wheel switch. Retest system. If resistance is more than 5 ohms, go to next step.

Check Clockspring For Open

Disconnect steering wheel switch in-line harness connector. Measure resistance of Brown/Light Blue wire between air bag sliding contact connector and steering wheel switch in-line to clockspring connector. If resistance is less than 5 ohms, replace steering wheel switch. Retest system. If resistance is more than 5 ohms, replace air bag sliding contact assembly. Retest system.