LEMON Manuals: Even more car manuals for everyone
Home >> Lexus >> 2017 >> GS 200t Base >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Communication Devices >> Can Communication System (Diagnostic Codes) (2 Of 2) & Circuit Tests >> Can Communication System >> DTC U1103: Lost Communication with Stop and Start Control Module [09/2014 - 10/2015] >> Procedure

DTC U1103: Lost Communication with Stop and Start Control Module [09/2014 - 10/2015]: Procedure

  1. CHECK SUB BUS 15 
    1. Measure the resistance according to the value(s) in the table below.
      GTY679304Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Resistance

      Tester Connection Condition Specified Condition Resistance: Malfunction
      A34-1 (CA3P) - A34-4 (CA3N) Cable disconnected from negative (-) battery terminal 54 to 69 Ω Below 53 Ω: Short in line
      A34-1 (CA3P) - A34-4 (CA3N) Cable disconnected from negative (-) battery terminal 54 to 69 Ω Higher than 70 Ω: Open in CAN main bus line
      A34-1 (CA3P) - A34-2 (+B) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Below 6 kΩ: +B short
      A34-4 (CA3N) - A34-2 (+B) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Below 6 kΩ: +B short
      A34-1 (CA3P) - A34-11 (E) Cable disconnected from negative (-) battery terminal 200 Ω or higher Below 200 Ω: Ground short
      A34-4 (CA3N) - A34-11 (E) Cable disconnected from negative (-) battery terminal 200 Ω or higher Below 200 Ω: Ground short
      TEXT IN ILLUSTRATION

      *a Component with harness connected
      (Certification ECU [Smart Key ECU Assembly])
      RESULT

      Result Proceed to
      OK A
      • Open circuit in CAN main bus line
      • Short circuit between bus lines
      		 B
      • Ground short
      • +B short
      		 C

    Result: 

    B 

    See step  3

    Result: 

    C 

    See step  6

    Result: 

    A 

    See step  2

  2. CHECK FOR DTC OUTPUT 
    1. Clear the DTCs.
    2. Turn the engine switch off.
    3. Turn the engine switch on (IG) and recheck for DTCs.
      RESULT

      Result Proceed to
      U1002 is output from certification ECU (smart key ECU assembly) (Techstream display / Smart Access) A
      Other DTC is output B

    Result: 

    A 

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) 

    (Refer to REMOVAL [09/2014 - ] )

    Result: 

    B 

    GO TO DIAGNOSIS PROCEDURE INDICATED BY OUTPUT DTC 

  3. CHECK FOR OPEN IN CAN BUS LINES (CERTIFICATION ECU) 
    1. Disconnect the certification ECU (smart key ECU assembly) connector.
      GTY647789Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A34-1 (CA3P) - A34-4 (CA3N) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      TEXT IN ILLUSTRATION

      *a Rear view of wire harness connector
      (to Certification ECU [Smart Key ECU Assembly])

    Result: 

    OK 

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) 

    (Refer to REMOVAL [09/2014 - ] )

    Result: 

    NG 

    See step  4

  4. CHECK FOR OPEN IN CAN BUS LINES (NO. 8 JUNCTION CONNECTOR) 
    1. Reconnect the certification ECU (smart key ECU assembly) connector.
      GTY685188Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the wire harness connector from the No. 8 junction connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A57-1 (CANH) - A57-12 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      A57-2 (CANH) - A57-13 (CANL) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      TEXT IN ILLUSTRATION

      *a Rear view of wire harness connector
      (to No. 8 Junction Connector)
      *b to ECM
      *c to Certification ECU (Smart Key ECU Assembly)
      RESULT

      Result Proceed to
      OK A
      NG (to Certification ECU main bus line) B
      NG (to ECM main bus line) C

    Result: 

    A 

    REPLACE NO. 8 JUNCTION CONNECTOR 

    Result: 

    B 

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NO. 8 JUNCTION CONNECTOR - CERTIFICATION ECU) 

    Result: 

    C 

    See step  5

  5. CHECK FOR OPEN IN CAN BUS LINES (ECM) 
    1. Reconnect the wire harness connector from the No. 8 junction connector.
      GTY666693Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the ECM connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A21-12 (CANP) - A12-11 (CANN) Cable disconnected from negative (-) battery terminal 108 to 132 Ω
      TEXT IN ILLUSTRATION

      *a Rear view of wire harness connector
      (to ECM)

    Result: 

    OK 

    REPLACE ECM 

    (Refer to REMOVAL [09/2014 - 10/2015] )

    Result: 

    NG 

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (ECM - NO. 8 JUNCTION CONNECTOR) 

  6. CHECK FOR SHORT IN CAN BUS LINES (CERTIFICATION ECU) 
    1. Disconnect the certification ECU (smart key ECU assembly) connector.
      GTY656413Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A34-1 (CA3P) - N20-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      A34-4 (CA3N) - N20-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      A34-1 (CA3P) - N20-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      A34-4 (CA3N) - N20-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      TEXT IN ILLUSTRATION

      *a Rear view of wire harness connector
      (to Certification ECU [Smart Key ECU Assembly])
      *b Front view of DLC3

    Result: 

    OK 

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) 

    (Refer to REMOVAL [09/2014 - ] )

    Result: 

    NG 

    See step  7

  7. CHECK FOR SHORT IN CAN BUS LINES (NO. 8 JUNCTION CONNECTOR) 
    1. Reconnect the certification ECU (smart key ECU assembly) connector.
      GTY631555Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *a Rear view of wire harness connector
      (to No. 8 Junction Connector)      		 *b Front view of DLC3
      *c to ECM *d to Certification ECU (Smart Key ECU Assembly)
    2. Disconnect the wire harness connector from the No. 8 junction connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition Purpose Connected to
      A57-1 (CANH) - N20-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher Inspection for CANH ground short ECM
      A57-12 (CANL) - N20-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher Inspection for CANL ground short
      A57-2 (CANH) - N20-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher Inspection for CANH ground short Certification ECU (smart key ECU assembly)
      A57-13 (CANL) - N20-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher Inspection for CANL ground short
      A57-1 (CANH) - N20-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short ECM
      A57-12 (CANL) - N20-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANL +B short
      A57-2 (CANH) - N20-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANH +B short Certification ECU (smart key ECU assembly)
      A57-13 (CANL) - N20-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher Inspection for CANL +B short
      RESULT

      Result Proceed to
      OK A
      NG (to Certification ECU main bus line) B
      NG (to ECM main bus line) C

    Result: 

    A 

    REPLACE NO. 8 JUNCTION CONNECTOR 

    Result: 

    B 

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (NO. 8 JUNCTION CONNECTOR - CERTIFICATION ECU) 

    Result: 

    C 

    See step  8

  8. CHECK FOR SHORT IN CAN BUS LINES (ECM) 
    1. Disconnect the ECM connector.
      GTY631047Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A21-12 (CANP) - N20-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      A21-11 (CANN) - N20-4 (CG) Cable disconnected from negative (-) battery terminal 200 Ω or higher
      A21-12 (CANP) - N20-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      A21-11 (CANN) - N20-16 (BAT) Cable disconnected from negative (-) battery terminal 6 kΩ or higher
      TEXT IN ILLUSTRATION

      *a Rear view of wire harness connector
      (to ECM)
      *b Front view of DLC3

    Result: 

    OK 

    REPLACE ECM 

    (Refer to REMOVAL [09/2014 - 10/2015] )

    Result: 

    NG 

    REPAIR OR REPLACE CAN MAIN BUS LINE OR CONNECTOR (ECM - NO. 8 JUNCTION CONNECTOR) 

scientia non olet · About LEMON Manuals