STEP 1. Using scan tool (M.U.T.-IIISE), check whether the other system DTC is set.
Check that the ETACS-ECU has not set a DTC.(1) caution | To prevent damage to scan tool (M.U.T.-IIISE), always turn the electric motor switch to the OFF position before connecting or disconnecting scan tool (M.U.T.-IIISE). |
Connect scan tool (M.U.T.-IIISE). Refer to "How to connect the Scan Tool (M.U.T.-IIISE)
".
(2) Turn the electric motor switch from OFF position to ON position.
(3) Check if DTC is set.
(4) Turn the electric motor switch to the OFF position.
Is the DTC set?
Carry out the diagnostic trouble code procedures (Refer to GROUP 54A - ETACS-ECU, diagnostic trouble code chart ). Go to Step 2.
STEP 2. Measure the voltage at the heater controller assembly (A/C-ECU) connector.
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Power supply mode of the electric motor switch: OFF → ON
(3) Voltage between IG1 terminal and body groundOK: The voltage should measure approximately 12 volts (battery positive voltage).
Is the check result normal?
Go to Step 4. Go to Step 3.
STEP 3. Check of open circuit in IG1 line between ETACS-ECU connector and heater controller assembly (A/C-ECU) connector.
STEP 4. Measure the voltage at the heater controller assembly (A/C-ECU) connector.
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Voltage between B/UP terminal and body ground.OK: The voltage should measure approximately 12 volts (battery positive voltage).
Is the check result normal?
Go to Step 6. Go to Step 5.
STEP 5. Check of open circuit in B/UP line between ETACS-ECU connector and heater controller assembly (A/C-ECU) connector.
STEP 6. Measure the resistance at the heater controller assembly (A/C-ECU) connector.
(1) Disconnect the connector, and measure at the wiring harness side.
(2) Resistance between E terminal and body groundOK: The resistance should be 2 ohms or less
Is the check result normal?
Replace the heater controller assembly (A/C-ECU) (Refer to ). Go to Step 7.
STEP 7. Check of open circuit in E line between heater controller assembly (A/C-ECU) connector and ground J/C (DASH) connector.