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DTC U1190: No receive fault detect signal
 
 
caution
  • If diagnostic trouble code No.U1190 is set in the occupant classification-ECU, diagnose the CAN main bus line.
  • Whenever the ECU is replaced, ensure that the communication circuit is normal.
 
 
DIAGNOSTIC TROUBLE CODE SET CONDITIONS
The occupant classification-ECU sets diagnostic trouble code No.U1190 when it cannot receive any signal for enabling/disabling diagnostic trouble code (U code) detection from the ETACS-ECU.
  • When the ignition switch is at "ON" position.
  • When the timer charging is in progress
  • When the pre-activated air conditioning is operating.
 
 
PROBABLE CAUSES
  • Malfunction of the CAN bus
  • Malfunction of the ETACS-ECU
  • Malfunction of the occupant classification-ECU
 
 
DIAGNOSIS
STEP 1. Using scan tool MB991958, diagnose the CAN bus line
(1)
cautionTo prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
Connect scan tool MB991958. Refer to "How to connect the Scan Tool MB991958 ."
(2) Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch from "ON" position to "LOCK" (OFF) position.
Is the CAN bus line found to be normal?
Go to Step 2.
Repair the CAN bus line. (Refer to GROUP 54C, Diagnosis ).
 
STEP 2. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
(1) Erase the DTC.
(2) Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch from "ON" position to "LOCK" (OFF) position.
Is the DTC set?
Go to Step 3.
It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions .
 
STEP 3. Recheck for diagnostic trouble code.
Check again if the DTC is set.
(1) Connect scan tool MB991958 to the data link connector
(2) Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3) Check if the DTC is set.
(4) Turn the ignition switch from "ON" position to "LOCK" (OFF) position.
Is the DTC set?
Replace the ETACS-ECU, and then go to Step 4.
The diagnosis is complete.
 
STEP 4. Recheck for diagnostic trouble code.
Check again if the DTC is set in the occupant classification-ECU.
(1) Erase the DTC.
(2) Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3) Check if DTC is set.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is the DTC set?
Replace the front seat cushion cover and pad assembly (Refer to GROUP 52A, Front Seat Assembly ).
There is an intermittent malfunction such as poor engaged connector(s) or open circuit (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).