Inspection Procedure 2: the TPMS Warning Light Flashes

INSPECTION PROCEDURE 2: The TPMS Warning Light Flashes.

TPMS Warning Light Signal Circuit Connectors: C-03, C-04, C-121:

CIRCUIT OPERATION
- The TPMS warning light will flash when a fault has occurred in the TPMS.
- The TPMS warning light may also flash when a fault has occurred in the TPMS warning light signal circuit (including open circuit and shorted circuit).

TECHNICAL DESCRIPTION (COMMENT)
- If any TPMS DTCs are set, carry out the relevant troubleshooting.
- If no TPMS DTC is set, carry out the troubleshooting for the TPMS warning light signal circuit.

TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THIS CASE:)
- A fault has occurred in the TPMS.
- Damaged harness wire or connector in the TPMS warning light signal circuit
- Malfunction of the combination meter
- Malfunction of the TPMS receiver

DIAGNOSIS
Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A

STEP 1. Using scan tool MB991958, read the diagnostic trouble code.

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.





(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Check whether any TPMS DTC is set.
Q:Is any TPMS DTC set?
YES: Carry out the relevant TPMS troubleshooting.
NO: Go to Step 2.

STEP 2. Check TPMS receiver connector C-121 and combination meter connector C-04 for loose, corroded or damaged terminals, or terminals pushed back in the connector. Pinout Values and Diagnostic Parameters

Connector: C-04:

Connector: C-121:

Q:Are TPMS receiver connector C-121 and combination meter connector C-04 in good condition?
YES: Go to Step 3.
NO: Repair it. Then go to Step 5.

STEP 3. Check the wiring harness between TPMS receiver connector C-121 (terminal 1 and 2) and combination meter connector C-04 (terminal 3 and 4). Pinout Values and Diagnostic Parameters

Connector: C-04:

Connector: C-121:

Connector: C-03:

NOTE: Also check joint connector (3) C-03 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If joint connector (3) C-03 is damaged, repair or replace the connector as described in Harness Connector Inspection.

Q:Are the wiring harness TPMS receiver connector C-121 (terminal 1 and 2) and combination meter connector C-04 (terminal 3 and 4) in good condition?
YES: Repair or replace it. Then go to Step 5.
NO: Go to Step 4.

STEP 4. Check the combination meter.
Check that the combination meter warning lights and indicators other than TPMS warning light illuminate normally.
Q:Are there any faults on the combination meter?
YES: Replace the combination meter assembly. Then go to Step 5.
NO: Replace the TPMS receiver and execute "Tire Pressure Sensor ID Registration" on scan tool M B991958 "Special Function". Then go to Step 5.

STEP 5. Retest the system.
Q:Turn the ignition switch to the "ON" position. Does the TPMS warning light illuminate for three seconds, and then go out?
YES: The procedure is complete.
NO: Repeat the troubleshooting from Step 1.