CAN Communication: Overview Lexus SC II рестайлинг

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1. BUS LINE REPAIR After repairing the bus line with solder, wrap the repaired part with vinyl tape. NOTE: The CANL bus line and CANH bus line must be installed together at all times. When installing, make sure to twist the lines. CAN bus lines are likely to be influenced by noise if the bus lines are not twisted. The difference in length of the CANL bus line and CANH bus line should be within 100 mm (3.94 in.). Make sure the length between each twist of the wire connecting the connectors is 80 mm (3.15 in.) or less. (Scheme 1): Identifying Wire Harness Repair Area Do not use bypass wiring between the connectors. NOTE: The characteristic of the twisted wire harness will be lost if you use bypass wiring. (Scheme 2): Caution For Do Not Use By-Pass Wiring Between Connectors
2. CONNECTOR HANDLING When inserting tester probes into a connector, insert them from the rear of the connector. (Scheme 3): Inserting Tester Probes Into Connector Use a repair wire to check the connector if it is impossible to check continuity from the rear of the connector. (Scheme 4): Checking Continuity From Rear Of Connector
3. PRECAUTION FOR DISCONNECTING BATTERY CABLE NOTE: When disconnecting the cable from the negative (-) battery terminal, initialize the following system after the cable is reconnected. SYSTEM REFERENCE System Name See procedure Meter / Gauge System «INITIALIZATION»(ref-283168-S15934672912008041900000) Front Power Seat Control System

HINT

The ECM uses the CAN communication system instead of the conventional communication line (SIL) to perform DTC communication.

SYSTEM DESCRIPTION

1. BRIEF DESCRIPTION The CAN (Controller Area Network) is a serial data communication system for real time application. It is a vehicle multiplex communication system which has a high communication speed (500 kbps) and the ability to detect malfunctions. By pairing the CANH and CANL bus lines, the CAN performs communication based on differential voltage. While the skid control ECU assembly uses the serial communication line, the ECM uses the CAN communication line. The translate ECU enables communication between the skid control ECU assembly and ECM by changing the communication method. The CAN has 2 resistors of 120 ohms, which are necessary to communicate with the main bus line.
2. DEFINITION OF TERMS Main bus line The main bus line is a wire harness between the 2 terminus circuits on the bus (communication line). This is the main bus in the CAN communication system. Sub bus line The sub bus line is a wire harness which diverges from the main bus line to an ECU or sensor. Terminus circuit The terminus circuit is a circuit placed to convert communication current of the CAN communication into bus voltage. It consists of a resistor and condenser. Two terminus circuits are necessary on a bus. CAN junction connector The CAN junction connector is a junction designed for CAN communication, which contains the terminus circuit.
3. ECU WHICH COMMUNICATE THROUGH CAN COMMUNICATION SYSTEM ECM Gateway ECU Translate ECU
4. DIAGNOSTIC TROUBLE CODE FOR CAN COMMUNICATION SYSTEM DTCs for the CAN communication system are as follows: U0073/42, U0100/65
5. REMARK FOR TROUBLESHOOTING Trouble in the CAN bus (communication line) can be checked from the DLC3 (except when there is a wire break other than in the sub bus line of the DLC3). NOTE: Do not insert the tester probes directly into the DLC3 connector. Be sure to use a service wire. DTCs related to the CAN communication system can be checked using the intelligent tester via the CAN VIM. The CAN communication system cannot detect trouble in the sub bus line of the DLC3 even though the DLC3 is also connected to the CAN communication system.
6. HOW TO DISTINGUISH CAN JUNCTION CONNECTOR In the CAN communication system, the shape of all the connectors connected to the CAN junction connector is the same. The connectors connected to the CAN junction connector can be distinguished by the colors of the bus line and the connecting side of the connector. HINT: See " «TERMINALS OF ECU»(ref-283179-S17880090342008041900000) " for bus line color or the type of connecting surface.

DESCRIPTION

TROUBLESHOOTING CHART

Gateway ECU Communication - Wiring Diagram. Scheme 5

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1. CHECK CAN BUS LINE FOR DISCONNECTION Disconnect the G3 gateway ECU connector. (Scheme 6): Identifying G3 Gateway ECU Connector Terminals Measure the resistance of the wire harness side connector. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition G3-17 (CA1H) - G3-18 (CA1L) Ignition switch OFF 54 to 69 ohms NG: REPAIR OR REPLACE GATEWAY ECU SUB BUS LINE AND CONNECTOR OK: Go to Next step
2. CHECK WIRE HARNESS (GATEWAY ECU - BATTERY AND BODY GROUND) Disconnect the G3 gateway ECU connector. (Scheme 7): Identifying G3 Gateway ECU Connector Terminals Measure the resistance of the wire harness side connector. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition G3-24 (GND) - Body ground Always Below 1 ohms Measure the voltage of the wire harness side connector. Standard voltage VOLTAGE SPECIFICATION Tester Connection Condition Specified Condition G3-10 (BATT) - Body ground Always 10 to 14 V G3-2 (ACC) - Body ground Ignition switch ACC 10 to 14 V G3-1 (IG) - Body ground Ignition switch ON 10 to 14 V NG: REPAIR OR REPLACE HARNESS AND CONNECTOR OK: REPLACE GATEWAY ECU

TROUBLESHOOTING CHART

Identifying ECM Communication - Wiring Diagram. Scheme 8

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1. INSPECT EFI RELAY (Marking: EFI) Remove the EFI relay from the engine room No. 2 relay block. (Scheme 9): Identifying EFI Relay Measure the resistance of the relay. Standard resistance RESISTANCE SPECIFICATION Tester Condition Specified Condition 3 - 5 10 kohms or higher 3-5 Below 1 ohms (when battery voltage is applied to terminals 1 and 2) NG: REPLACE EFI RELAY OK: Go to Next step
2. CHECK WIRE HARNESS (EFI RELAY - ECM, BATTERY AND BODY GROUND) Remove the EFI relay from the engine room No. 2 relay block. Disconnect the E4 and E6 ECM connectors. (Scheme 10): Identifying EFI Relay And E4, E6 Connector Terminals Measure the voltage of the wire harness side connector. Standard voltage VOLTAGE SPECIFICATION Tester Connection Specified Condition EFI relay terminal 5 - Body ground 10 to 14 V Measure the resistance of the wire harness side connectors. Standard resistance RESISTANCE SPECIFICATION Tester Connection Specified Condition EFI relay terminal 2 - E6-13 (MREL) Below 1 ohms EFI relay terminal 1 - Body ground Below 1 ohms EFI relay terminal 3 - E6-6 (+B) Below 1 ohms EFI relay terminal 3 - E6-5 (+B1) Below 1 ohms E4-2 (E01) - Body ground Below 1 ohms NG: REPAIR OR REPLACE HARNESS AND CONNECTOR OK: REPLACE ECM

TROUBLESHOOTING CHART

Translate ECU Communication - Wiring Diagram. Scheme 11

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1. CHECK WIRE HARNESS (TRANSLATE ECU - BATTERY AND BODY GROUND) Disconnect the T28 translate ECU connector. (Scheme 12): Identifying T28 Translate ECU Connector Terminals Measure the resistance of the wire harness side connector. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition T28-40 (GND) - Body ground Always Below 1 ohms Measure the voltage of the wire harness side connector. Standard voltage VOLTAGE SPECIFICATION Tester Connection Condition Specified Condition T28-1 (IGI) - Body ground Ignition switch ON 10 to 14 V NG: REPAIR OR REPLACE HARNESS AND CONNECTOR OK: REPLACE TRANSLATE ECU

When any DTC for the CAN communication system is output, first measure the resistance between the terminals of the DLC3 to specify the trouble area, and check that there is no short in the CAN main bus line, between the CAN bus lines, to B+, or to GND.

CAN Bus Line - Wiring Diagram. Scheme 13

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1. CHECK CAN BUS WIRE (MAIN BUS LINE FOR DISCONNECTION, BUS LINES FOR SHORT CIRCUIT) Disconnect the G3 gateway ECU connector. (Scheme 14): Identifying G3 Gateway ECU Connector Measure the resistance of the DLC3. (Scheme 15): Identifying DLC3 Connector Terminals Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition Proceed to D1-6 (CANH) - D1-14 (CANL) Ignition switch OFF 54 to 69 ohms OK D1-6 (CANH) - D1-14 (CANL) Ignition switch OFF 69 ohms or more NG-A D1-6 (CANH) - D1-14 (CANL) Ignition switch OFF 54 ohms or less NG-B NG-A: CHECK FOR OPEN IN CAN MAIN BUS LINE NG-B: CHECK FOR SHORT IN CAN BUS LINE OK: Go to Next step
2. CONNECT CONNECTOR Reconnect the G3 gateway ECU connector.
3. CHECK CAN BUS WIRE (FOR SHORT TO B+) Measure the resistance of the DLC3. (Scheme 16): Identifying DLC3 Connector Terminals Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition D1-6 (CANH) - D1-16 (BAT) Ignition switch OFF 1 Mohms or higher D1-14 (CANL) - D1-16 (BAT) Ignition switch OFF 1 Mohms or higher NG: CHECK FOR SHORT TO B+ IN CAN BUS LINE OK: Go to Next step
4. CHECK CAN BUS WIRE (FOR SHORT TO GND) Measure the resistance of the DLC3. (Scheme 17): Identifying DLC3 Connector Terminals Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition D1-4 (CG) - D1-6 (CANH) Ignition switch OFF 1 kohms or higher D1-4 (CG) - D1-14 (CANL) Ignition switch OFF 1 kohms or higher NG: CHECK FOR SHORT TO GND IN CAN BUS LINE OK: HOW TO PROCEED WITH TROUBLESHOOTING

There may be an open circuit in the CAN main bus line and / or the DLC3 sub bus line when the resistance between terminals 6 (CANH) and 14 (CANL) of the DLC3 is 69 ohms or higher.

TROUBLESHOOTING CHART

CAN Main Bus Line - Wiring Diagram. Scheme 18

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1. CHECK DLC3 Measure the resistance of the DLC3. (Scheme 19): Identifying DLC3 Connector Terminals Result RESULT CHART Tester Connection Condition Specified Condition Proceed to D1-6 (CANH) - D1-14 (CANL) Ignition switch OFF 108 to 132 ohms A D1-6 (CANH) - D1-14 (CANL) Ignition switch OFF 132 ohms or higher B NOTE: When the measured value is 132 ohms or higher and a CAN communication system diagnostic trouble code is output, there may be a fault besides disconnection of the DLC3 sub bus line. For that reason, troubleshooting should be performed again from " «HOW TO PROCEED WITH TROUBLESHOOTING»(ref-283179-S28993708122008041900000) " after repairing the trouble area. B: REPAIR OR REPLACE DLC3 SUB BUS LINE AND CONNECTOR (CANH, CANL) A: Go to Next step
2. CHECK CAN MAIN BUS LINE FOR DISCONNECTION (FOR ECM) Disconnect the J25 CAN junction connector. (Scheme 20): Identifying J25 CAN Junction Connector Terminals Measure the resistance of the wire harness side connector. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition J25-10 (CANH) - J25-21 (CANL) Ignition switch OFF 108 to 132 ohms NG: Go to step 4 OK: Go to Next step
3. CHECK CAN MAIN BUS LINE FOR DISCONNECTION (FOR TRANSLATE ECU) Disconnect the J25 CAN junction connector. (Scheme 21): Identifying J25 CAN Junction Connector Terminals Measure the resistance of the wire harness side connector. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition J25-11 (CANH) - J25-22 (CANL) Ignition switch OFF 108 to 132 ohms NG: Go to step 5 OK: REPAIR OR REPLACE CAN JUNCTION CONNECTOR
4. CHECK ECM Disconnect the E6 ECM connector. (Scheme 22): Identifying E6 ECM Connector Terminals Measure the resistance of the ECM. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition E6-25 (CANH) - E6-24 (CANL) Ignition switch OFF 108 to 132 ohms NG: REPLACE ECM OK: REPAIR OR REPLACE ECM MAIN BUS LINE AND CONNECTOR
5. CHECK TRANSLATE ECU Disconnect the T28 translate ECU connector. (Scheme 23): Identifying T28 Translate ECU Connector Terminals Measure the resistance of the translate ECU. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition T28-8 (CANH) - T28-10 (CANL) Ignition switch OFF 108 to 132 ohms NG: REPLACE TRANSLATE ECU OK: REPAIR OR REPLACE TRANSLATE ECU MAIN BUS LINE AND CONNECTOR

There may be a short circuit between the CAN bus lines when the resistance between terminals 6 (CANH) and 14 (CANL) of the DLC3 is below 54 ohms.

TROUBLESHOOTING CHART

CAN Bus Lines - Wiring Diagram. Scheme 24

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1. CHECK CAN BUS LINES FOR SHORT CIRCUIT (DLC3 SUB BUS LINE) Disconnect the J25 CAN junction connector. (Scheme 25): Identifying J25 CAN Junction Connector Terminals Measure the resistance of the DLC3. (Scheme 26): Identifying DLC3 Connector Terminal Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition D1-6 (CANH) - D1-14 (CANL) Ignition switch OFF 1 Mohms or higher NG: REPAIR OR REPLACE DLC3 SUB BUS LINE AND CONNECTOR OK: Go to Next step
2. CONNECT CONNECTOR Reconnect the J25 CAN junction connector.
3. CHECK CAN BUS LINES FOR SHORT CIRCUIT (ECM MAIN BUS LINE) Disconnect the E6 ECM connector. (Scheme 27): Identifying E6 ECM Connector Terminals Measure the resistance of the DLC3. (Scheme 28): Identifying DLC3 Connector Terminals Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition D1-6(CANH)-D1-14 (CANL) Ignition switch OFF 108 to 132 ohms OK: REPLACE ECM NG: Go to Next step
4. CHECK CAN BUS LINES FOR SHORT CIRCUIT (ECM MAIN BUS LINE) Disconnect the J25 CAN junction connector. Disconnect the E6 ECM connector. (Scheme 29): Identifying E6 ECM Connector Terminals Measure the resistance of the wire harness side connector. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition E6-25 (CANH) - E6-24 (CANL) Ignition switch OFF 1 Mohms or higher NG: REPAIR OR REPLACE ECM MAIN BUS LINE AND CONNECTOR OK: Go to Next step
5. CONNECT CONNECTOR Reconnect the J25 CAN junction connector. Reconnect the E6 ECM connector.
6. CHECK CAN BUS LINES FOR SHORT CIRCUIT (TRANSLATE ECU MAIN BUS LINE) Disconnect the T28 translate ECU connector. (Scheme 30): Identifying T28 Translate ECU Connector Terminals Measure the resistance of the DLC3. (Scheme 31): Identifying DLC3 Connector Terminals Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition D1-6 (CANH) - D1-14 (CANL) Ignition switch OFF 108 to 132 ohms OK: REPLACE TRANSLATE ECU NG: Go to Next step
7. CHECK CAN BUS LINES FOR SHORT CIRCUIT (TRANSLATE ECU MAIN BUS LINE) Disconnect the J25 CAN junction connector. (Scheme 32): Identifying J25 CAN Junction Connector Terminals Disconnect the T28 translate ECU connector. (Scheme 33): Identifying T28 Translate ECU Connector Terminals Measure the resistance of the wire harness side connector. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition T28-8(CANH)-T28-10 (CANL) Ignition switch OFF 1 Mohms or higher NG: REPAIR OR REPLACE TRANSLATE ECU MAIN BUS LINE AND CONNECTOR OK: Go to Next step
8. CONNECT CONNECTOR Reconnect the J25 CAN junction connector. Reconnect the T28 translate ECU connector.
9. CHECK CAN BUS LINES FOR SHORT CIRCUIT (GATEWAY ECU SUB BUS LINE) Disconnect the G3 gateway ECU connector. (Scheme 34): Identifying G3 Gateway ECU Connector Terminals Measure the resistance of the DLC3. (Scheme 35): Identifying DLC3 Connector Terminals Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition D1-6 (CANH) - D1-14 (CANL) Ignition switch OFF 54 to 69 ohms OK: REPLACE GATEWAY ECU NG: Go to Next step
10. CHECK CAN BUS LINES FOR SHORT CIRCUIT (GATEWAY ECU SUB BUS LINE) Disconnect the J25 CAN junction connector. (Scheme 36): Identifying J25 CAN Junction Connector Terminals Disconnect the G3 gateway ECU connector. (Scheme 37): Identifying G3 Gateway ECU Connector Terminals Measure the resistance of the wire harness side connector. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition G3-17 (CA1H) - G3-18 (CA1L) Ignition switch OFF 1 Mohms or higher NG: CHECK AND REPLACE GATEWAY ECU SUB BUS LINE AND CONNECTOR OK: REPAIR OR REPLACE CAN JUNCTION CONNECTOR

There may be a short circuit between the CAN bus line and B+ when there is resistance between terminals 6 (CANH) and 16 (BAT) or terminals 14 (CANL) and 16 (BAT) of the DLC3.

TROUBLESHOOTING CHART

CAN Bus Line - Wiring Diagram. Scheme 38

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1. CHECK CAN BUS LINES FOR SHORT TO B+ (DLC3 SUB BUS LINE) Disconnect the cable from the negative (-) battery terminal. Disconnect the J25 CAN junction connector. (Scheme 39): Identifying J25 CAN Junction Connector Terminals Measure the resistance of the DLC3. (Scheme 40): Identifying DLC3 Connector Terminals Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition D1-6 (CANH) - 01-16 (BAT) Ignition switch OFF 1 Mohms or higher D1-14 (CANL) - D1-16 (BAT) Ignition switch OFF 1 Mohms or higher NG: REPAIR OR REPLACE DLC3 SUB BUS LINE AND CONNECTOR OK: Go to Next step
2. CONNECT CONNECTOR Reconnect the J25 CAN junction connector.
3. CHECK CAN BUS LINES FOR SHORT TO B+ (ECM MAIN BUS LINE) Disconnect the cable from the negative (-) battery terminal. Disconnect the E6 ECM connector. (Scheme 41): Identifying E6 ECM Connector Terminals Measure the resistance of the DLC3. (Scheme 42): Identifying DLC3 Connector Terminals Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition D1-6 (CANH) - D1-16 (BAT) Ignition switch OFF 1 Mohms or higher D1-14 (CANL) - D1-16 (BAT) Ignition switch OFF 1 Mohms or higher OK: REPLACE ECM NG: Go to Next step
4. CHECK CAN BUS LINES FOR SHORT TO B+ (ECM MAIN BUS LINE) Disconnect the cable from the negative (-) battery terminal. Disconnect the J25 CAN junction connector. (Scheme 43): Identifying J25 CAN Junction Connector Terminals Disconnect the E6 ECM connector. (Scheme 44): Identifying E6 ECM Connector Terminals Measure the resistance of the wire harness side connector. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition E6-25 (CANH) - E6-4 (BATT) Ignition switch OFF 1 Mohms or higher E6-24 (CANL) - E6-4 (BATT) Ignition switch OFF 1 Mohms or higher NG: REPAIR OR REPLACE ECM MAIN BUS LINE AND CONNECTOR OK: Go to Next step
5. CONNECT CONNECTOR Reconnect the J25 CAN junction connector. Reconnect the E6 ECM connector.
6. CHECK CAN BUS LINES FOR SHORT TO B+ (TRANSLATE ECU MAIN BUS LINE) Disconnect the cable from the negative (-) battery terminal. Disconnect the T28 translate ECU connector. (Scheme 45): Identifying T28 Translate ECU Connector Measure the resistance of the DLC3. (Scheme 46): Identifying DLC3 Connector Terminals Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition D1-6 (CANH) - D1-16 (BAT) Ignition switch OFF 1 Mohms or higher D1-14 (CANL) - D1-16 (BAT) Ignition switch OFF 1 Mohms or higher OK: REPLACE TRANSLATE ECU NG: Go to Next step
7. CHECK CAN BUS LINES FOR SHORT TO B+ (TRANSLATE ECU MAIN BUS LINE) Disconnect the cable from the negative (-) battery terminal. Disconnect the J25 CAN junction connector. (Scheme 47): Identifying J25 CAN Junction Connector Disconnect the T28 translate ECU connector. (Scheme 48): Identifying T28 Translate ECU Connector Terminals Measure the resistance of the wire harness side connector. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition T28-8 (CANH) - D1-16 (BAT) Ignition switch OFF 1 Mohms or higher T28-10 (CANL) - D1-16 (BAT) Ignition switch OFF 1 Mohms or higher NG: REPAIR OR REPLACE TRANSLATE ECU MAIN BUS LINE AND CONNECTOR OK: Go to Next step
8. CONNECT CONNECTOR Reconnect the J25 CAN junction connector. Reconnect the T28 translate ECU connector.
9. CHECK CAN BUS LINES FOR SHORT TO B+ (GATEWAY ECU SUB BUS LINE) Disconnect the cable from the negative (-) battery terminal. Disconnect the G3 gateway ECU connector. (Scheme 49): Identifying G3 Gateway ECU Connector Measure the resistance of the DLC3. (Scheme 50): Identifying DLC3 Connector Terminals Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition D1-6 (CANH) - D1-16 (BAT) Ignition switch OFF 1 Mohms or higher D1-14 (CANL) - D1-16 (BAT) Ignition switch OFF 1 Mohms or higher OK: REPLACE GATEWAY ECU NG: Go to Next step
10. CHECK CAN BUS LINES FOR SHORT TO B+ (GATEWAY ECU SUB BUS LINE) Disconnect the cable from the negative (-) battery terminal. Disconnect the J25 CAN junction connector. (Scheme 51): Identifying J25 CAN Junction Connector Disconnect the G3 gateway ECU connector. (Scheme 52): Identifying G3 Gateway ECU Connector Terminals Measure the resistance of the wire harness side connector. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition G3-17 (CA1H) - G3-10 (BATT) Ignition switch OFF 1 Mohms or higher G3-18 (CA1L) - G3-10 (BATT) Ignition switch OFF 1 Mohms or higher NG: REPAIR OR REPLACE GATEWAY ECU SUB BUS LINE AND CONNECTOR OK: REPAIR OR REPLACE CAN JUNCTION CONNECTOR

A short to GND may be occurring in the CAN bus line when there is a short between terminals 4 (CG) and 6 (CANH) or terminals 4 (CG) and 14 (CANL) of the DLC3.

TROUBLESHOOTING CHART

CAN Bus Line - Wiring Diagram. Scheme 53

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1. CHECK CAN BUS LINE FOR SHORT TO GND (DLC3 SUB BUS LINE) Disconnect the J25 CAN junction connector. (Scheme 54): Identifying J25 CAN Junction Connector Measure the resistance of the DLC3. (Scheme 55): Identifying DLC3 Connector Terminals Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition D1-6 (CANH) - D1-4 (CG) Ignition switch OFF 1 Mohms or higher D1-14 (CANL) - D1-4 (CG) Ignition switch OFF 1 Mohms or higher NG: REPAIR OR REPLACE DLC3 SUB BUS LINE AND CONNECTOR OK: Go to Next step
2. CONNECT CONNECTOR Reconnect the J25 CAN junction connector.
3. CHECK CAN BUS LINE FOR SHORT TO GND (ECM MAIN BUS LINE) Disconnect the E6 ECM connector. (Scheme 56): Identifying E6 ECM Connector Measure the resistance of the DLC3. (Scheme 57): Identifying DLC3 Connector Terminals Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition D1-6 (CANH) - D1-4 (CG) Ignition switch OFF 1 kohms or higher D1-14 (CANL) - D1-4 (CO) Ignition switch OFF 1 kohms or higher OK: REPLACE ECM NG: Go to Next step
4. CHECK CAN BUS LINE FOR SHORT TO GND (ECM MAIN BUS LINE) Disconnect the J25 CAN junction connector. (Scheme 58): Identifying J25 CAN Junction Connector Disconnect the E6 ECM connector. (Scheme 59): Identifying E6 ECM Connector Terminals Measure the resistance of the wire harness side connector. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition E6-25 (CANH) - Body ground Ignition switch OFF 1 Mohms or higher E6-24 (CANL) - Body ground Ignition switch OFF 1 Mohms or higher NG: REPAIR OR REPLACE ECM MAIN BUS LINE AND CONNECTOR OK: Go to Next step
5. CONNECT CONNECTOR Reconnect the E6 ECM connector. Reconnect the J25 CAN junction connector.
6. CHECK CAN BUS LINE FOR SHORT TO GND (TRANSLATE ECU MAIN BUS LINE) Disconnect the T28 translate ECU connector. (Scheme 60): Identifying T28 Translate ECU Connector Measure the resistance of the DLC3. (Scheme 61): Identifying DLC3 Connector Terminals Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition D1-6 (CANH) - D1-4 (CG) Ignition switch OFF 1 kohms or higher D1-14 (CANL) - D1-4 (CG) Ignition switch OFF 1 kohms or higher OK: REPLACE TRANSLATE ECU NG: Go to Next step
7. CHECK CAN BUS LINE FOR SHORT TO GND (TRANSLATE ECU MAIN BUS LINE) Disconnect the J25 CAN junction connector. (Scheme 62): Identifying J25 CAN Junction Connector Disconnect the T28 translate ECU connector. (Scheme 63): Identifying T28 Translate ECU Connector Terminals Measure the resistance of the wire harness side connector. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition T28-8 (CANH) - Body ground Ignition switch OFF 1 Mohms or higher T28-10 (CANL) - Body ground Ignition switch OFF 1 Mohms or higher NG: REPAIR OR REPLACE TRANSLATE ECU MAIN BUS LINE AND CONNECTOR OK: Go to Next step
8. CONNECT CONNECTOR Reconnect the J25 CAN junction connector. Reconnect the T28 translate ECU connector.
9. CHECK CAN BUS LINE FOR SHORT TO GND (GATEWAY ECU SUB BUS LINE) Disconnect the G3 gateway ECU connector. (Scheme 64): Identifying G3 Gateway ECU Connector Measure the resistance of the DLC3. (Scheme 65): Identifying DLC3 Connector Terminals Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition D1-6 (CANH) - D1-4 (CG) Ignition switch OFF 1 kohms or higher D1-14 (CANL) - D1-4 (CG) Ignition switch OFF 1 kohms or higher OK: REPLACE GATEWAY ECU NG: Go to Next step
10. CHECK CAN BUS LINE FOR SHORT TO GND (GATEWAY ECU SUB BUS LINE) Disconnect the J25 CAN junction connector. (Scheme 66): Identifying J25 CAN Junction Connector Disconnect the G3 gateway ECU connector. (Scheme 67): Identifying G3 Gateway ECU Connector Terminals Measure the resistance of the wire harness side connector. Standard resistance RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition G3-17 (CA1H) - Body ground Ignition switch OFF 1 Mohms or higher G3-18 (CA1L) - Body ground Ignition switch OFF 1 Mohms or higher NG: REPAIR OR REPLACE GATEWAY ECU SUB BUS LINE AND CONNECTOR OK: REPAIR OR REPLACE CAN JUNCTION CONNECTOR