Test No. 5: Foglight Switch Signal Is Not Sent To ETACS ECU
- Turn ignition off. Disconnect foglight switch. Test foglight switch by checking for continuity between foglight switch terminals No. 6 7. See Fig 1
. With foglight switch released (off), continuity should not be indicated. With foglight switch pressed (on), continuity should be indicated. If foglight switch tests as specified, go to next step. If foglight switch does not test as specified, replace foglight switch. Recheck foglight switch input signal.
- Using DVOM, measure resistance between foglight switch connector terminal No. 7 (Black wire) and ground. If resistance is greater than 2 ohms, go to next step. If resistance is 2 ohms or less, go to step 5
.
- Check for poor connections at foglight switch connector terminals. If poor connections are found, repair as necessary. Recheck foglight switch input signal. If terminals are okay, go to next step.
- Check for open in Black wire between foglight switch connector terminal No. 7 and ground. If faulty circuit is found, repair as necessary. Recheck foglight switch input signal. If circuit is okay, system is okay at this time.
- Check for poor connections at ETACS ECU connector C313 and foglight switch connector terminals. See Figure
. If poor connections are found, repair as necessary. Recheck foglight switch input signal. If terminals are okay, go to next step.
- Check for faulty Light Blue wire between foglight switch connector terminal No. 6 and ETACS ECU connector C313 terminal No. 45. See Figure
. If faulty circuit is found, repair as necessary. Recheck foglight switch input signal. If circuit is okay, replace ETACS ECU.
Courtesy of DAIMLERCHRYSLER CORP.