Inspection Procedure 2

INSPECTION PROCEDURE 2: Check The Satellite Radio Tuner Power Supply Circuit.

CAUTION: Before replacing the satellite radio tuner, antenna feeder cable, ensure that the power supply circuit, the ground circuit and the communication circuit are normal.

Satellite Radio Tuner Supply Circuit:

TECHNICAL DESCRIPTION (COMMENT)
If the satellite radio tuner functions do not work at all, the satellite radio tuner power supply system, ground system, or satellite radio tuner may have a problem.

TROUBLESHOOTING HINTS
- The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
- The satellite radio tuner may be defective

DIAGNOSIS

Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe

STEP 1. Check satellite radio tuner connectors C-18 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q: Is satellite radio tuner connectors C-18 in good condition?

YES : Go to Step 2.

NO : Repair or replace the damaged component(s).

STEP 2. Check the ground circuit to the satellite radio tuner. Measure the resistance at satellite radio tuner connectors C-18.

1. Disconnect satellite radio tuner connector C-18 and measure the resistance available at the wiring harness side of the connector.







2. Measure the resistance value between satellite radio tuner connector C-18 terminal 8 and ground.
- The resistance should be 2 ohms or less.

Q: Is the measured resistance 2 ohms or less?

YES : Go to Step 4.

NO : Go to Step 3.

STEP 3. Check the wiring harness between satellite radio tuner connector C-18 (terminal 8) and ground.

Q: Is the wiring harness between satellite radio tuner connector C-18 (terminal 8) and ground in good condition?

YES : No action is necessary and testing is complete.

NO : The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary.

STEP 4. Check the power supply circuit to the satellite radio tuner. Measure the voltage at satellite radio tuner connector C-18.

1. Disconnect the connector, and measure at the wiring harness-side connector.







2. Measure the voltage between terminal 1 and ground.

OK: Battery positive voltage

Q: Is the measured voltage battery positive voltage?

YES : Go to Step 6.

NO : Go to Step 5.

STEP 5. Check the wiring harness between satellite radio tuner connector C-18 (terminal 1) and fusible link (36).

NOTE: Also check ETACS-ECU connectors C-307 and C-317 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If ETACS-ECU connector C-307 or C-317 is damaged, repair or replace the connector.

Q: Is the wiring harness between satellite radio tuner connector C-18 (terminal 1) and fusible link (36) in good condition?

YES : No action is necessary and testing is complete.

NO : The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary. The system should communicate with the satellite radio tuner normally.

STEP 6. Retest the system

Check if the satellite radio tuner works normally.

Q: Is the check result normal?

YES : The trouble can be an intermittent malfunction.

NO : Replace the satellite radio tuner.