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DTC B1034: Ambient air temperature sensor system (short circuit)
DTC B1035: Ambient air temperature sensor system (open circuit)
 
 
 
 
DTC SET CONDITION
  • DTC B1034 is set if there is a short circuit in the ambient air temperature sensor input circuit.
  • DTC B1035 is set if there is a defective connector connection, or if there is an open circuit in the harness.
 
 
 
TECHNICAL DESCRIPTION (COMMENT)
Current trouble
  • The ETACS-ECU, the ambient air temperature sensor, or connector(s) or wiring between the two may be defective.
Past trouble
  • If DTC B1034 or B1035 is set as a past trouble, carry out diagnosis with particular emphasis on wiring and connector(s) between the ETACS-ECU and the ambient air temperature sensor. If the connectors and wiring are normal, and obviously the ECU is the cause of the trouble, replace the ECU. If in doubt, do not replace the ECU.
 
 
 
TROUBLESHOOTING HINT
  • The wiring harness or connectors may have loose, corroded, or damaged terminals, or terminals pushed back in the connector
  • Malfunction of the ambient air temperature sensor.
  • Malfunction of the ETACS-ECU.
 
 
 
DIAGNOSIS
Required Special Tools:
  • MB991223: Harness Set
  • MB992006: Extra Fine Probe
STEP 1. Using scan tool (M.U.T.-III), check data list (ETACS-ECU).
(1)
cautionTo prevent damage to scan tool (M.U.T.-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-III).
Connect scan tool (M.U.T.-III). Refer to "How to connect the Scan Tool (M.U.T.-III) ."
(2) Check that the following service data display contents are normal. (Refer to GROUP 54A, ETACS-ECU Date list reference table ).
Item No.252: Ambient air temperature Sensor
Is the check result normal?
Go to Step 5.
Go to Step 2.
 
STEP 2. Using scan tool (M.U.T.-III), diagnose the CAN bus line
Use the M.U.T.-III to diagnose the CAN bus lines.
Is the check result normal?
Go to Step 3.
Repair the CAN bus lines. (Refer to GROUP 54C, Troubleshooting ).
 
STEP 3. Check of open circuit in AMB+ and AMB- line (ETACS-ECU) between ambient temperature sensor connector and ETACS-ECU connector.
Is the check result normal?
Go to Step 4.
Repair the connector(s) or wiring harness.
 
STEP 4. Inspection of the ambient temperature sensor
Refer to .
Is the check result normal?
Go to Step 5.
Replace the ambient temperature sensor.
 
STEP 5. Retest the system.
Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).
Replace the ETACS-ECU.