INSPECTION PROCEDURE B-6: Tone alarm: Low fuel level tone alarm function does not work normally.: Diagnosis
Required Special Tools:
- MB991223: Test Harness Set
- MB991502: Scan Tool (MUT-II)
- MB991529: Diagnostic Trouble Code Check Harness
- STEP 1. Check the low fuel level warning light operation.
Q: Does the low fuel level warning light work normally?
YES : Go to Step 2 (Scan Tool) or Step 3 (voltmeter).
NO: Check the combination meter and fuel pump module. Refer to INSTRUMENT PANEL SYSTEM - COUPE .
- STEP 2. Check the input signal (by using scan tool MB991502).
Check the input signals from the ignition switch (IG1).
CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.- Connect scan tool MB991502 to the data link connector.
- Check that the tone alarm of scan tool MB991502 sounds when the input signal enters.
Q: Does the tone alarm of scan tool MB991502 sound when the input signal enters.
YES : Replace the ETACS-ECU. The low fuel level tone alarm function should work normally.
NO: Scan tool MB991502 does not sound when the ignition switch is turned from "ACC" to "ON": Refer to INSPECTION PROCEDURE O-2 "THE IGNITION SWITCH (IG1) SIGNAL IS NOT SENT TO THE ETACS-ECU ."
- STEP 3. Check the input signal (by using a voltmeter).
Check the input signals from the ignition switch (IG1).
- Use special tool MB991529 to connect a voltmeter between ground terminal 4 or 5 and ETACS-ECU terminal 9 of the data link connector.
- Check that the voltmeter indicator deflects once when the input signal enters.
Q: Does the voltmeter indicator deflect?
YES : Replace the ETACS-ECU. The low fuel level tone alarm function should work normally.
NO: The voltmeter needle does not fluctuate when the ignition switch is turned from "ACC" to "ON": Refer to INSPECTION PROCEDURE O-2 "THE IGNITION SWITCH (IG1) SIGNAL IS NOT SENT TO THE ETACS-ECU ."