Diagnostic Item 20
DIAGNOSTIC ITEM 20: Diagnose the lines between CAN main bus line and the combination meterCAUTION: When servicing a CAN bus line, ground yourself by touching a metal object such as an unpainted water pipe. If you fail to do so, a component connected to the CAN bus line may be damaged.
(Part 1):
(Part 1):
TROUBLE JUDGMENT
If the M.U.T.-III cannot received signals from the combination meter, CAN bus line connector(s) are broken or an open circuit has occurred.
COMMENTS ON TROUBLE SYMPTOM
The wiring harness wire or connectors may have loose, corroded, or damage terminals, or terminals pushed back in the connector, or the combination meter may be defective.
TROUBLESHOOTING HINTS
- The wiring harness or connectors may have loose, corroded, or damage terminals, or terminals pushed back in the connector
- The combination meter may be defective
DIAGNOSIS
Required Special Tools:
- MB991223: Harness Set
- MB992006: Extra Fine Probe
STEP 1. Check joint connector (4) C-101 and combination meter connector C-102 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
NOTE: For the removal of the joint connector.
CAUTION: The strand end of the twist wire should be within 10 cm (4 inches) from the connector.
Check the joint connector at the wiring harness side for loose, corroded or damaged terminals, or terminals pushed back in the connector, and also check the short pin behind the connector for corrosion, deformation and delamination.
Q: Are joint connector (4) C-101 and combination meter connector C-102 in good condition?
YES : Go to Step 2.
NO : Repair the damaged parts. Replace the joint connector as necessary.
STEP 2. Check the CAN bus lines between joint connector (4) and the combination meter. Measure the resistance between joint connector (4) C-101 and combination meter connector C-102.
CAUTION:
- A digital multimeter should be used.
- The test wiring harness should be used.
1. Disconnect joint connector (4) C-101 and combination meter connector C-102, and measure the resistance between each wiring harness side connector.
2. Turn the ignition switch to the "LOCK" (OFF) position.
CAUTION: Disconnect the negative battery terminal.
3. Disconnect the negative battery terminal.
4. Measure the resistance between joint connector (4) terminal 4 and combination meter connector terminal 15.
OK: 2 ohms or less
5. Measure the resistance between joint connector (4) terminal 15 and combination meter connector terminal 14.
CAUTION: Strictly observe the specified wiring harness repair procedure.
Q: Do all the resistances measure 2 ohms or less?
YES : [All the resistances measure 2 ohms or less] Power supply to the combination meter may be suspected. Diagnose the combination meter.
NO : [If either of the resistances measures more than 2 ohms or all the resistances measure more than 2 ohms] Repair the wiring harness between joint connector (4) and the combination meter connector.