Controller Area Network (CAN): Diagnosis Mitsubishi Eclipse IV

TEST EQUIPMENT

TEST EQUIPMENT CHART TEST EQUIPMENT NAME USE Digital multimeter Checking CAN bus circuit (for resistance and voltage measurements)

Scheme 1

EXPLANATION ABOUT THE SCAN TOOL (MUT-III) CAN BUS DIAGNOSTICS

Scan tool MB991958 CAN bus diagnostics carries out the three checks below automatically, and then displays the current condition of the CAN bus lines according to the check results.

Scheme 2

Scheme 3

Scheme 4

Scheme 5

Scheme 6

Scheme 7

Scheme 8

Scheme 9

Scheme 10

Scheme 11

1. Scan tool CAN bus diagnostics Scan tool MB991958 diagnoses CAN bus lines in accordance with the following strategy. Measuring voltage in CAN bus line Diagnoses the power supply (such as wires of higher voltage than CAN communication line) and grounding (such as wires of lower voltage than CAN communication line) of CAN bus lines for short circuit by measuring the voltages between the CAN_L line or H line and body ground. CAN BUS LINE VOLTAGE SPECIFICATION MEASURE THE VOLTAGE NORMAL VALUE MEASUREMENT VALUE TROUBLE WHEN THE MEASUREMENT VALUE DOES NOT MEET THE NORMAL VALUE NOTE Between the CAN_L line and body ground 0 V or more and 4.0 V or less Less than 1.0 V Short to ground of the CAN_L line If the CAN_L or H line is shorted to ground or power supply, a DTC may not be set. More than 4.0 V A short to the power supply of the CAN_L line Between the CAN_H line and body ground 0 V or more and 4.0 V or less Less than 1.0 V Short to ground of the CAN_H line More than 4.0 V A short to the power supply of the CAN_H line Measuring resistance in CAN bus line Checks the terminator resistors (incorporated in the combination meter, the engine control module (ECM) < M/T > or the powertrain control module (PCM) < A/T >), which are connected to each end of a CAN bus line, for breakage and a CAN bus main line for open circuit by measuring the resistance value between a CAN_L line and H line. CAN BUS LINE RESISTANCE SPECIFICATION NORMAL VALUE MEASUREMENT VALUE TROUBLE WHEN THE MEASUREMENT VALUE DOES NOT MEET THE NORMAL VALUE NOTE 60 +/- 10 ohms 120 +/- 20 ohms Trouble in a CAN main bus line or terminator resistor If only one terminator resistor is broken at either side, the CAN communication will continue although noise suppression is deteriorated. If a CAN main bus line is open circuit, the CAN communication is suspended at that open circuit point. No continuity Trouble in CAN main bus line or between the data link connector and main bus line - 2 ohms or less CAN bus line (between CAN_L and H lines) is shorted If a CAN bus line is shorted, all ECUs cease communicating each other (This fail-safe function is called "Bus off"). Other than above Poorly engaged connector - Checking the communication condition of ECUs REFERENCE CIRCUIT Scan tool MB991958 narrows down troubles in circuit by itself. Its strategy is as follows: CAN COMMUNICATION TROUBLE CHART ECU WHICH CAN NOT COMMUNICATE WITH THE SCAN TOOL POSSIBLE TROUBLE SPOT LOGIC FOR DETERMINING DOWN TROUBLE SPOT ECU A CAN bus line (a) and power supply system to ECU A ECU A communicates with scan tool MB991958 via CAN bus lines (a) and (b). Scan tool MB991958 judges that CAN bus line (b) is normal, because it can communicate with other ECUs. Possible trouble may be present in CAN bus line (a) or the power supply system to ECU A. ECU C CAN bus line (g) and power supply system to ECU C ECU C communicates with scan tool MB991958 via CAN bus lines (b), (c), (d) and (g). Scan tool MB991958 judges that CAN bus lines (b), (c) and (d) are normal, because it can communicate with ECUs B and D. Possible trouble may be present in CAN bus line (g) or the power supply system to ECU C. ECU C and ECU D Trouble in CAN bus line (d) ECUs C and D communicate with scan tool MB991958 via CAN bus lines (b), (c), (d), (e) and (g). Scan tool MB991958 judges that CAN bus lines (b) and (c) are normal, because it can communicate with ECU B. Possible trouble may be present in CAN bus line (d), (e) or (g) or the power supply system to ECU D. CAN bus line (d) is shared by ECUs C and D when they communicate with scan tool MB991958, so CAN bus line (d) is suspected as ultimate cause. CAN bus line (g) or (e) and power supply systems to ECU C or D are also suspected as second cause. ECU B and ECU D CAN bus line (e) or (f) or power supply system to ECU B or D ECUs C and D communicate with scan tool MB991958 via CAN bus lines (b), (c), (d), (e) and (g). Scan tool MB991958 judges that CAN bus lines (b), (c) and (d) are normal, because it can communicate with ECU C. Possible trouble may be present in CAN bus line (f) or (e) or the power supply system to ECU B or D.
2. If DTC code related to CAN communication is set as past trouble, isolate opens as described below. NOTE: If you pinpoint trouble spot according to DTC code, you should use time-out DTC code. DTC code related to failure information is set when the data to be set contains an error, so CAN bus line itself is probably normal. NOTE: Time-out DTC codes are stored in each ECU memory individually. Therefore, it is possible that these DTC codes have not been set simultaneously. If the trouble spot cannot be found when you diagnose by judging from multiple DTC codes, check the communication lines between each ECU. DTC CODE TROUBLE CHART DTC CODE TO BE SET POSSIBLE TROUBLE SPOT LOGIC FOR DETERMINING TROUBLE SPOT Time-out DTC code associated with ECU D is stored in ECU A, ECU B and ECU C Trouble in CAN bus line (e) and power supply system to ECU D When time-out DTC code associated with ECU D is stored in ECU A, B and C, or time-out DTC code associated with ECUs A, B and C is stored in ECU D, or "bus off" DTC code is stored in ECU D, CAN bus line (e) is suspected. When DTC code is not stored in ECU D, the power supply to ECU D is suspected. Time-out DTC code associated with ECUs A, B and C is stored in ECU D "Bus off" DTC code is stored in ECU D Time-out DTC code associated with ECU A is stored in ECUs B, C and D Trouble in CAN bus line (a) and power supply system to ECU A When time-out DTC code associated with ECU A is stored in ECUs B, C and D, or time-out DTC code associated with ECUs B, C and D is stored in ECU A, or "bus off" DTC code is stored in ECU A, CAN bus line (a) or (c) is suspected. When DTC code is not stored in ECU A, the power supply to ECU A is suspected. Time-out DTC code associated with ECUs B, C and D is stored in ECU A "Bus off" DTC code is stored in ECU A Time-out DTC codes associated with ECUs C and D are stored in ECU A and ECU B Trouble in CAN bus line (d) If time-out DTC codes associated with ECUs C and D are stored in ECUs A and B, or time-out codes associated with ECUs A and B are stored in ECUs C and D, CAN bus line (d) is suspected. CAN bus line (g) or (e) and power supply systems to ECU C or D are also suspected as second cause. Time-out DTC codes associated with ECUs A and B are stored in ECU C and ECU D

ON-BOARD DIAGNOSTICS

The CAN is a communication method which the ECUs use in order to communicate each other. The CAN-related diagnostic trouble codes will be stored in the following ECUs, which use the CAN communication.

1. ECM < M/T > or PCM < A/T >
2. ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system >
3. ETACS-ECU
4. A/C-ECU
5. SRS-ECU
6. Combination meter

HOW TO CONNECT THE SCAN TOOL (MUT-III)

Required Special Tools

1. MB991958: Scan Tool (MUT-III Sub Assembly) MB991824: Vehicle Communication Interface (V.C.I.) MB991827: MUT-III USB Cable MB991910: MUT-III Main Harness A

Scheme 12

1. Ensure that the ignition switch is at the "LOCK" (OFF) position.
2. Start up the personal computer.
3. Connect special tool MB991827 to special tool MB991824 and the personal computer.
4. Connect special tool MB991910 to special tool MB991824.
5. Connect special tool MB991910 to the data link connector.
6. Turn the power switch of special tool MB991824 to the "ON" position. NOTE: When special tool MB991824 is energized, special tool MB991824 indicator light will be illuminated in a green color.
7. Start the MUT-III system on the personal computer. NOTE: Disconnecting scan tool MB991958 is the reverse of the connecting sequence, making sure that the ignition switch is at the "LOCK" (OFF) position.

HOW TO DIAGNOSE THE CAN BUS LINE

Required Special Tools

1. MB991958: Scan Tool (MUT-III Sub Assembly) MB991824: Vehicle Communication Interface (V.C.I.) MB991827: MUT-III USB Cable MB991910: MUT-III Main Harness A

1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Select "CAN bus diagnosis" from the start-up screen.
4. When the vehicle information is displayed, confirm that it matches the vehicle whose CAN bus lines will be diagnosed. If they match, go to Step 8 . If not, go to step 5.
5. Select the "view vehicle information" button.
6. Enter the vehicle information and select the "OK" button.
7. When the vehicle information is displayed, confirm again that it matches the vehicle whose CAN bus lines will be diagnosed. If they match, go to step 8. If not, go to Step 5 .
8. Select the "OK" button.
9. When the optional equipment screen is displayed, choose the one which the vehicle is fitted with, and then select the "OK" button.

CAN BUS DIAGNOSTICS TABLE

This diagnosis applies only to the CAN bus lines. If a different system is defective, proceed to the applicable diagnosis section for each system. Observe the diagnosis procedure below only when the CAN bus line is defective.

CAN BUS DIAGNOSTICS SCAN TOOL SCREEN DIAGNOSIS DETAIL < Comment > Short circuit to battery in red displayed area is estimated. DIAGNOSTIC ITEM 1 Diagnose shorts in the power supply to CAN bus line < Comment > Grounding in red displayed area is estimated. DIAGNOSTIC ITEM 2 Diagnose shorts in the ground to CAN bus line < Comment > Short circuit between CAN_H and CAN_L in red displayed area is estimated. DIAGNOSTIC ITEM 3 Diagnose shorts between CAN_H and L lines < Comment > Disconnection in red displayed area is estimated. < Comment > Disconnection or terminating resistance in red displayed area is estimated. DIAGNOSTIC ITEM 4 Diagnose the terminator resistors < Comment > Harness disconnection or loose connection in red displayed area is estimated. DIAGNOSTIC ITEM 5 Diagnose when the scan tool cannot receive the data sent by combination meter. < Comment > Harness disconnection or loose connection in red displayed area is estimated. DIAGNOSTIC ITEM 6 Diagnose when the scan tool cannot receive the data sent by ETACS-ECU. < Comment > Harness disconnection or loose connection in red displayed area is estimated. DIAGNOSTIC ITEM 7 Diagnose when the scan tool cannot receive the data sent by A/C-ECU. < Comment > Harness disconnection or loose connection in red displayed area is estimated. DIAGNOSTIC ITEM 8 Diagnose when the scan tool cannot receive the data sent by SRS-ECU. < Comment > Harness disconnection or loose connection in red displayed area is estimated. DIAGNOSTIC ITEM 9 Diagnose when the scan tool cannot receive the data sent by the ECM < M/T > or the PCM < A/T >. < Comment > Harness disconnection or loose connection in red displayed area is estimated. DIAGNOSTIC ITEM 10 Diagnose when the scan tool cannot receive the data sent by ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system >. < Comment > Harness disconnection or loose connection in red displayed area is estimated. DIAGNOSTIC ITEM 11 Diagnose when the scan tool cannot receive the data sent by the ECM < M/T > or the PCM < A/T > and ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system >. < Comment > Malfunction in red displayed area is estimated. Please refer to service manual and inspect with 'CAN Detail Diagnosis'. DIAGNOSTIC ITEM 12 Diagnose CAN bus lines thoroughly

Scheme 13

Scheme 14

Scheme 15

Scheme 16

Scheme 17

Scheme 18

Scheme 19

Scheme 20

Scheme 21

Scheme 22

Scheme 23

Scheme 24

Scheme 25

Note. If the screen other than above is displayed, troubles are present at two or more spots. In this case, diagnose CAN bus lines by referring to the trouble spot pinpoint procedures.

Note. If a trouble cannot be solved after performing the diagnosis other than item 4, diagnose CAN bus line thoroughly.

DIAGNOSTIC ITEM 1: Diagnose shorts in the power supply to CAN bus line

Scheme 26

Scheme 27

TROUBLESHOOTING HINTS

1. The wiring harness may be defective (CAN bus lines for a short to the power supply, combination meter, ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system >, or open circuit in the SRS-ECU ground line).
2. Short to power supply of the connector
3. Each ECU may be defective (short to power supply in the ECU)

DIAGNOSIS

Required Special Tools

1. MB991223: Harness Set
2. MB992006: Extra Fine Probe
3. MB991958: Scan Tool (MUT-III Sub Assembly) MB991824: Vehicle Communication Interface (V.C.I.) MB991827: MUT-III USB Cable MB991910: MUT-III Main Harness A
4. MB991970: ABS Check Harness

Scheme 28

Scheme 29

Scheme 30

Scheme 31

Scheme 32

Scheme 33

Scheme 34

Scheme 35

Scheme 36

Scheme 37

Scheme 38

Scheme 39

Scheme 40

Scheme 41

Scheme 42

Scheme 43

Scheme 44

Scheme 45

Scheme 46

Scheme 47

Scheme 48

Scheme 49

Scheme 50

Scheme 51

Scheme 52

Scheme 53

Scheme 54

Scheme 55

Scheme 56

Scheme 57

Scheme 58

Scheme 59

Scheme 60

Scheme 61

Scheme 62

Scheme 63

Scheme 64

1. STEP 1. Check the CAN bus lines for a short to the power supply. Measure the voltage at data link connector C-125. CAUTION: A digital multimeter should be used. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). The test wiring harness should be used. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). NOTE: This inspection allows you to check that there is a short to power supply in either CAN_H line or CAN_L line. Disconnect ECM < M/T > or PCM < A/T > connector B-18 and combination meter connector C-04, and measure the voltage at the harness side of data link connector C-125. Turn the ignition switch to the "ON" position. Measure the voltage between data link connector terminal 6 (CAN_H) and body ground. OK: 4.0 volts or less Measure the voltage between data link connector terminal 14 (CAN_L) and body ground. OK: 4.0 volts or less Q: Is the check result normal? YES: Go to Step 14. NO: Go to Step 2.
2. STEP 2. Check the CAN line of the front wiring harness for a short to the power supply. Measure the voltage at intermediate connector C-24. Disconnect intermediate connector C-24, and measure the voltage at the male side (at front wiring harness side). Turn the ignition switch to the "ON" position. Measure the voltage between intermediate connector terminal 11 (CAN_H) and body ground. OK: 4.0 volts or less Measure the voltage between intermediate connector terminal 12 (CAN_L) and body ground. OK: 4.0 volts or less Q: Is the check result normal? YES : Go to Step 3. NO : Go to Step 11 .
3. STEP 3. Check the CAN line between joint connector (3) and the combination meter for a short to the power supply. Measure the voltage at joint connector (3) C-03. Disconnect joint connector (3) C-03, and measure the voltage at the wiring harness side of joint connector (3) C-03. Turn the ignition switch to the "ON" position. Measure the voltage between joint connector (3) terminal 4 (CAN_H) and body ground. OK: 4.0 volts or less Measure the voltage between joint connector (3) terminal 15 (CAN_L) and body ground. OK: 4.0 volts or less CAUTION: Strictly observe the specified wiring harness repair procedure. For details refer to «PRECAUTIONS ON HOW TO REPAIR THE CAN BUS LINES»(ref-241285-S35921930502006081100000). Q: Is the check result normal? YES: Go to Step 4. NO: Repair the wiring harness between joint connector (3) and the combination meter connector.
4. STEP 4. Check the CAN line between joint connector (3) and the ETACS-ECU connector for a short to the power supply. Measure the voltage at joint connector (3) C-03. Disconnect joint connector (3) C-03, and measure the voltage at the wiring harness side of joint connector (3) C-03. Turn the ignition switch to the "ON" position. Measure the voltage between joint connector (3) terminal 5 (CAN_H) and body ground. OK: 4.0 volts or less Measure the voltage between joint connector (3) terminal 16 (CAN_L) and body ground. OK: 4.0 volts or less Q: Is the check result normal? YES : Go to Step 5. NO : Go to Step 8 .
5. STEP 5. Check the CAN line between joint connector (3) and the A/C-ECU connector for a short to the power supply. Measure the voltage at joint connector (3) C-03. Disconnect joint connector (3) C-03, and measure the voltage at the wiring harness side of joint connector (3) C-03. Turn the ignition switch to the "ON" position. Measure the voltage between joint connector (3) terminal 6 (CAN_H) and body ground. OK: 4.0 volts or less Measure the voltage between joint connector (3) terminal 17 (CAN_L) and body ground. OK: 4.0 volt or less Q: Is the check result normal? YES : Go to Step 6. NO : Go to Step 9 .
6. STEP 6. Check the CAN line between joint connector (3) and the SRS-ECU connector for short to the power supply. Measure the voltage at joint connector (3) C-03. Disconnect joint connector (3) C-03, and measure the voltage at the wiring harness side of joint connector (3) C-03. Turn the ignition switch to the "ON" position. Measure the voltage between joint connector (3) terminal 3 (CAN_H) and body ground. OK: 4.0 volts or less Measure the voltage between joint connector (3) terminal 14 and body ground. OK: 4.0 volt or less Q: Is the check result normal? YES : Go to Step 7. NO : Go to Step 10 .
7. STEP 7. Check the CAN line between joint connector (3) and the data link connector for a short to the power supply. Measure the voltage at joint connector (3) C-03. Disconnect joint connector (3) C-03, and measure the voltage at the wiring harness side of joint connector (3) C-03. Turn the ignition switch to the "ON" position. Measure the voltage between joint connector (3) terminal 7 (CAN_H) and body ground. OK: 1.0 volt or less Measure the voltage between joint connector (3) terminal 18 (CAN_L) and body ground. OK: 1.0 volt or less CAUTION: Strictly observe the specified wiring harness repair procedure. For details refer to «PRECAUTIONS ON HOW TO REPAIR THE CAN BUS LINES»(ref-241285-S35921930502006081100000). Q: Is the check result normal? YES: Repair the wiring harness between joint connector (3) and the intermediate connector, or the intermediate connector. NO: Repair the wiring harness between joint connector (3) and the data link connector, or the data link connector.
8. STEP 8. Check the ETACS-ECU for a short to the power supply. Disconnect ETACS-ECU connector C-218. CAUTION: To 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 to the data link connector. Diagnose CAN bus lines, and check if scan tool MB991958 screen is as shown in the illustration. Q: Does scan tool MB991958 screen correspond to the illustration? YES: Repair the wiring harness between joint connector (3) and the ETACS-ECU connector. NO: Check the ETACS-ECU connector, and repair if necessary. If the ETACS-ECU connector is in good condition, replace the ETACS-ECU. When the ETACS-ECU is replaced, register the encrypted code. Refer to «ENCRYPTED CODE REGISTRATION CRITERIA TABLE»(ref-241292-S39211918422006081100000).
9. STEP 9. Check the A/C-ECU for a short to the power supply. Disconnect A/C-ECU connector C-14 < manual air conditioning system > or C-15 < automatic air conditioning system >. CAUTION: To 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 to the data link connector. Diagnose CAN bus lines, and check if scan tool MB991958 screen is as shown in the illustration. Q: Does scan tool MB991958 screen correspond to the illustration? YES : Repair the wiring harness between joint connector (3) and the A/C-ECU connector. NO : Check the A/C-ECU connector, and repair if necessary. If the A/C-ECU connector is in good condition, replace the A/C-ECU.
10. STEP 10. Check the SRS-ECU for a short to the power supply. Disconnect SRS-ECU connector C-123. CAUTION: To 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 to the data link connector. Diagnose CAN bus lines, and check if scan tool MB991958 screen is as shown in the illustration. Q: Does scan tool MB991958 screen correspond to the illustration? YES: Repair the wiring harness between joint connector (3) and the SRS-ECU connector. NO: Check the SRS-ECU connector, and repair if necessary. If the SRS-ECU connector is in good condition, refer to Supplemental restraint system - SRS Air Bag Diagnosis - «INSPECTION PROCEDURE 2: POWER SUPPLY CIRCUIT SYSTEM»(ref-241293-S29159199932006081100000).
11. STEP 11. Check the CAN line between intermediate connector C-24 and ABS-ECU connector < vehicles without traction control system > or ABS/TCL-ECU < vehicles with TLC > connector for a short to the power supply. Measure the voltage at intermediate connector C-24. Disconnect intermediate connector C-24 and ABS-ECU connector A-02 < vehicles without traction control system > or ABS/TCL-ECU connector A-03 < vehicles with traction control system >, and measure the voltage at the male side of intermediate connector C-24 (at front wiring harness side). Turn the ignition switch to the "ON" position. Measure the voltage between intermediate connector terminal 11 (CAN_H) and body ground. OK: 1.0 volt or less Measure the voltage between intermediate connector terminal 12 (CAN_L) and body ground. OK: 1.0 volt or less CAUTION: Strictly observe the specified wiring harness repair procedure. For details refer to «PRECAUTIONS ON HOW TO REPAIR THE CAN BUS LINES»(ref-241285-S35921930502006081100000). Q: Is the check result normal? YES: Go to Step 12. NO: Repair the wiring harness.
12. STEP 12. Check the CAN line between the ECM < M/T > or PCM < A/T > connector and ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > connector for a short to the power supply. Measure voltage at ECM < M/T > or PCM < A/T > connector B-18. Disconnect ECM < M/T > or PCM < A/T > connector B-18 and ABS-ECU connector A-02 < vehicles without traction control system > or ABS/TCL-ECU connector A-03 < vehicles with traction control system >, and measure the voltage at the harness side of ECM < M/T > or PCM < A/T > connector B-18. Turn the ignition switch to the "ON" position. Measure the voltage between ECM < M/T > or PCM < A/T > connector terminal 17 (CAN_H) and body ground. OK: 1.0 volt or less Measure the voltage between ECM < M/T > or PCM < A/T > connector terminal 18 (CAN_L) and body ground. OK: 1.0 volt or less CAUTION: Strictly observe the specified wiring harness repair procedure. For details refer to «PRECAUTIONS ON HOW TO REPAIR THE CAN BUS LINES»(ref-241285-S35921930502006081100000). Q: Is the check result normal? YES: Go to Step 13. NO: Repair the wiring harness between ECM < M/T > or PCM < A/T > connector and ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > connector.
13. STEP 13. Retest the system. CAUTION: To 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 to the data link connector. Diagnose CAN bus lines, and check if scan tool MB991958 screen shows normal state. Q: Is the check result normal? YES: Intermittent malfunction. NO: Check the ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > connector, and repair if necessary. If the ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > connector is in good condition, refer to Anti-skid Braking System - «INSPECTION PROCEDURE 2: ABS-ECU POWER SUPPLY CIRCUIT SYSTEM»(ref-241327-S22780094452006081100000).
14. STEP 14. Check the combination meter for a short to the power supply. Disconnect combination meter connector C-04. CAUTION: To 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 to the data link connector. Diagnose CAN bus lines, and check if scan tool MB991958 screen is as shown in the illustration. Q: Does scan tool MB991958 screen correspond to the illustration? YES : Go to Step 15. NO : Go to Step 16 .
15. STEP 15. Check the ECM < M/T > or PCM < A/T > connector for a short to the power supply. Disconnect ECM < M/T > or PCM < A/T > connector B-18. CAUTION: To 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 to the data link connector. Diagnose CAN bus lines, and check if scan tool MB991958 screen is as shown in the illustration. Q: Does scan tool MB991958 screen correspond to the illustration? YES : Intermittent malfunction. NO : Go to Step 17 .
16. STEP 16. Retest the system. CAUTION: To 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 to the data link connector. Diagnose CAN bus lines, and check if scan tool MB991958 screen shows normal state. Q: Is the check result normal? YES: Intermittent malfunction. NO: Check the combination meter connector, and repair if necessary. If the combination meter connector is in good condition, refer to Chassis Electrical - Combination Meter - «INSPECTION PROCEDURES»(ref-241292-S04931418222006081100000).
17. STEP 17. Retest the system. CAUTION: To 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 to the data link connector. Diagnose CAN bus lines, and check if scan tool MB991958 screen shows normal state. Q: Is the check result normal? YES: Intermittent malfunction. NO: Check the ECM < M/T > or PCM < A/T > connector, and repair if necessary. If the ECM < M/T > or PCM < A/T > connector is in good condition, replace the ECM < M/T > or PCM < A/T >. When the ECM < M/T > or PCM < A/T > is replaced, register the encrypted code. Refer to «ENCRYPTED CODE REGISTRATION CRITERIA TABLE»(ref-241292-S39211918422006081100000).

DIAGNOSTIC ITEM 2: Diagnose shorts in the ground to CAN bus line

Scheme 65

Scheme 66

1. The wiring harness may be defective (CAN bus lines or the wiring harness between the data link connector and joint connector (3) for short to ground)
2. The connectors may be defective (short to ground in the connector)
3. Each ECU may be defective (short to ground in the ECU)

Required Special Tools

1. MB991223: Harness Set
2. MB992006: Extra Fine Probe
3. MB991958: Scan Tool (MUT-III Sub Assembly) MB991824: Vehicle Communication Interface (V.C.I.) MB991827: MUT-III USB Cable MB991910: MUT-III Main Harness A
4. MB991970: ABS Check Harness

Scheme 67

Scheme 68

Scheme 69

Scheme 70

Scheme 71

Scheme 72

Scheme 73

Scheme 74

Scheme 75

Scheme 76

Scheme 77

Scheme 78

Scheme 79

Scheme 80

Scheme 81

Scheme 82

Scheme 83

Scheme 84

Scheme 85

Scheme 86

Scheme 87

Scheme 88

Scheme 89

Scheme 90

Scheme 91

Scheme 92

Scheme 93

Scheme 94

1. STEP 1. Check the CAN bus lines for short to ground. Measure the resistance at data link connector C-125. CAUTION: A digital multimeter should be used. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). The test wiring harness should be used. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). NOTE: This inspection allows you to check that there is a short to ground in either CAN_H line or CAN_L line. CAUTION: Disconnect the negative battery terminal. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). Disconnect the negative battery terminal. Disconnect ECM < M/T > or PCM < A/T > connector B-18 and combination meter connector C-04, and measure the resistance at the harness side of data link connector C-125. Measure the resistance between data link connector terminal 6 (CAN_H) and body ground. OK: 1 kohms or more Measure the resistance between data link connector terminal 14 (CAN_L) and body ground. OK: 1 kohms or more Q: Is the check result normal? YES: Go to Step 14. NO: Go to Step 2.
2. STEP 2. Check the CAN bus line of the front wiring harness for short to ground. Measure the resistance at intermediate connector C-24. CAUTION: Disconnect the negative battery terminal. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). Disconnect the negative battery terminal. Disconnect intermediate connector C-24, and measure the resistance at the male side (at front wiring harness side). Measure the resistance between intermediate connector terminal 11 (CAN_H) and body ground. OK: 1 ohms or more Measure the resistance between intermediate connector terminal 12 (CAN_L) and body ground. OK: 1 kohms or more Q: Is the check result normal? YES: Go to Step 3. NO: Go to Step 11.
3. STEP 3. Check the CAN line between joint connector (3) and the combination meter for short to ground. Measure the resistance at joint connector (3) C-03. CAUTION: Disconnect the negative battery terminal. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). Disconnect the negative battery terminal. Disconnect joint connector (3) C-03, and measure the resistance at the wiring harness side of joint connector (3) C-03. Measure the resistance between joint connector (3) terminal 4 (CAN_H) and body ground. OK: 1 kohms or more Measure the resistance between joint connector (3) terminal 15 (CAN_L) and body ground. OK: 1 kohms or more CAUTION: Strictly observe the specified wiring harness repair procedure. For details refer to «PRECAUTIONS ON HOW TO REPAIR THE CAN BUS LINES»(ref-241285-S35921930502006081100000). Q: Is the check result normal? YES: Go to Step 4. NO: Repair the wiring harness between joint connector (3) and the combination meter connector.
4. STEP 4. Check the CAN line between joint connector (3) and the ETACS-ECU connector for short to ground. Measure the resistance at joint connector (3) C-03. CAUTION: Disconnect the negative battery terminal. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). Disconnect the negative battery terminal. Disconnect joint connector (3) C-03, and measure the resistance at the wiring harness side of joint connector (3) C-03. Measure the resistance between joint connector (3) terminal 5 (CAN_H) and body ground. OK: 1 kohms or more Measure the resistance between joint connector (3) terminal 16 (CAN_L) and body ground. OK: 1 kohms or more Q: Is the check result normal? YES: Go to Step 5. NO: Go to Step 8.
5. STEP 5. Check the CAN line between joint connector (3) and the A/C-ECU connector for short to ground. Measure the resistance at joint connector (3) C-03. CAUTION: Disconnect the negative battery terminal. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). Disconnect the negative battery terminal. Disconnect joint connector (3) C-03, and measure the resistance at the wiring harness side of joint connector (3) C-03. Measure the resistance between joint connector (3) terminal 6 (CAN_H) and body ground. OK: 1 kohms or more Measure the resistance between joint connector (3) terminal 17 (CAN_L) and body ground. OK: 1 kohms or more Q: Is the check result normal? YES: Go to Step 6. NO: Go to Step 9.
6. STEP 6. Check the CAN line between joint connector (3) and the SRS-ECU connector for short to ground. Measure the resistance at joint connector (3) C-03. CAUTION: Disconnect the negative battery terminal. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). Disconnect the negative battery terminal. Disconnect joint connector (3) C-03, and measure the resistance at the wiring harness side of joint connector (3) C-03. Measure the resistance between joint connector (3) terminal 3 and body ground. OK: 1 kohms or more Measure the resistance between joint connector (3) terminal 14 and body ground. OK: 1 kohms or more Q: Does the resistance measure 1 kohms or more? YES: Go to Step 7. NO: Go to Step 10.
7. STEP 7. Check the CAN line between joint connector (3) and the data link connector for short to ground. Measure the resistance at joint connector (3) C-03. CAUTION: Disconnect the negative battery terminal. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). Disconnect the negative battery terminal. Disconnect joint connector (3) C-03, and measure the resistance at the wiring harness side of joint connector (3) C-03. Measure the resistance between joint connector (3) terminal 7 (CAN_H) and body ground. OK: 1 kohms or more Measure the resistance between joint connector (3) terminal 18 (CAN_L) and body ground. OK: 1 kohms or more CAUTION: Strictly observe the specified wiring harness repair procedure. For details refer to «PRECAUTIONS ON HOW TO REPAIR THE CAN BUS LINES»(ref-241285-S35921930502006081100000). Q: Does the resistance measure 1 kohms or more? YES: Repair the wiring harness between joint connector (3) and the intermediate connector. NO: Repair the wiring harness between joint connector (3) and the data link connector.
8. STEP 8. Check the ETACS-ECU for a short to ground. Disconnect ETACS-ECU connector C-218. CAUTION: To 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 to the data link connector. Diagnose CAN bus lines, and check if scan tool MB991958 screen is as shown in the illustration. Q: Does scan tool MB991958 screen correspond to the illustration? YES: Repair the wiring harness between joint connector (3) and the ETACS-ECU connector. NO: Check the ETACS-ECU connector, and repair if necessary. If the ETACS-ECU connector is in good condition, replace the ETACS-ECU. When the ETACS-ECU is replaced, register the encrypted code. Refer to «ENCRYPTED CODE REGISTRATION CRITERIA TABLE»(ref-241292-S39211918422006081100000).
9. STEP 9. Check the A/C-ECU for a short to ground. Disconnect A/C-ECU connector C-14 < manual air conditioning system > or C-15 < automatic air conditioning system >. CAUTION: To 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 to the data link connector. Diagnose CAN bus lines, and check if scan tool MB991958 screen is as shown in the illustration. Q: Does scan tool MB991958 screen correspond to the illustration? YES : Repair the wiring harness between joint connector (3) and the A/C-ECU connector. NO : Check the A/C-ECU connector, and repair if necessary. If the A/C-ECU connector is in good condition, replace the A/C-ECU.
10. STEP 10. Check the SRS-ECU for a short to ground. Disconnect SRS-ECU connector C-123. CAUTION: To 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 to the data link connector. Diagnose CAN bus lines, and check if scan tool MB991958 screen is as shown in the illustration. Q: Does scan tool MB991958 screen correspond to the illustration? YES : Repair the wiring harness between joint connector (3) and the SRS-ECU connector. NO : Check the SRS-ECU connector, and repair if necessary. If the SRS-ECU connector is in good condition, replace the SRS-ECU.
11. STEP 11. Check the CAN line between intermediate connector C-24 and ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > connector for a short to ground. Measure the resistance at intermediate connector C-24. CAUTION: Disconnect the negative battery terminal. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). Disconnect the negative battery terminal. Disconnect intermediate connector C-24 and ABS-ECU connector A-02 < vehicles without traction control system > or ABS/TCL-ECU connector A-03 < vehicles with traction control system >, and measure the resistance at the male side of intermediate connector C-24 (at front wiring harness side). Measure the resistance between intermediate connector terminal 11 (CAN_H) and body ground. OK: 1 kohms or more Measure the resistance between intermediate connector terminal 12 (CAN_L) and body ground. OK: 1 kohms or more CAUTION: Strictly observe the specified wiring harness repair procedure. For details refer to «PRECAUTIONS ON HOW TO REPAIR THE CAN BUS LINES»(ref-241285-S35921930502006081100000). Q: Is the check result normal? YES: Go to Step 12. NO: Repair the wiring harness.
12. STEP 12. Check the CAN line between the ECM < M/T > or PCM < A/T > connector and ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > connector for a short to ground. Measure the resistance at ECM < M/T > or PCM < A/T > connector B-18. CAUTION: Disconnect the negative battery terminal. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). Disconnect the negative battery terminal. Disconnect ECM < M/T > or PCM < A/T > connector B-18 and ABS-ECU connector A-02 < vehicles without traction control system > or ABS/TCL-ECU connector A-03 < vehicles with traction control system >, and measure the resistance at the harness side of ECM < M/T > or PCM < A/T > connector B-18. Measure the resistance between ECM < M/T > or PCM < A/T > connector terminal 17 and body ground. OK: 1 kohms or more Measure the resistance between ECM < M/T > or PCM < A/T > connector terminal 18 and body ground. OK: 1 kohms or more CAUTION: Strictly observe the specified wiring harness repair procedure. For details refer to «PRECAUTIONS ON HOW TO REPAIR THE CAN BUS LINES»(ref-241285-S35921930502006081100000). Q: Is the check result normal? YES: Go to Step 13. NO: Repair the wiring harness between ECM < M/T > or PCM < A/T > connector and ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > connector.
13. STEP 13. Retest the system. CAUTION: To 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 to the data link connector. Diagnose CAN bus lines, and check if scan tool MB991958 screen shows normal state. Q: Is the check result normal? YES : Intermittent malfunction. NO : Check the ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > connector, and repair if necessary. If the ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > connector is in good condition, replace the ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system >.
14. STEP 14. Check the combination meter for a short to ground. Disconnect combination meter connector C-04. CAUTION: To 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 to the data link connector. Diagnose CAN bus lines, and check if scan tool MB991958 screen is as shown in the illustration. Q: Does scan tool MB991958 screen correspond to the illustration? YES : Go to Step 15. NO : Go to Step 16 .
15. STEP 15. Check the ECM < M/T > or PCM < A/T > for a short to ground. Disconnect ECM < M/T > or PCM < A/T > connector B-18. CAUTION: To 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 to the data link connector. Diagnose CAN bus lines, and check if scan tool MB991958 screen is as shown in the illustration. Q: Does scan tool MB991958 screen correspond to the illustration? YES : Intermittent malfunction. NO : Go to Step 17 .
16. STEP 16. Retest the system. CAUTION: To 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 to the data link connector. Diagnose CAN bus lines, and check if scan tool MB991958 screen shows normal state. Q: Is the check result normal? YES : Intermittent malfunction. NO : Check the combination meter connector, and repair if necessary. If the combination meter connector is in good condition, replace the combination meter.
17. STEP 17. Retest the system. CAUTION: To 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 to the data link connector. Diagnose CAN bus lines, and check if scan tool MB991958 screen shows normal state. Q: Is the check result normal? YES: Intermittent malfunction. NO: Check the ECM < M/T > or PCM < A/T > connector, and repair if necessary. If the ECM < M/T > or PCM < A/T > connector is in good condition, replace the ECM < M/T > or PCM < A/T >. When the ECM < M/T > or PCM < A/T > is replaced, register the encrypted code. Refer to «ENCRYPTED CODE REGISTRATION CRITERIA TABLE»(ref-241292-S39211918422006081100000).

DIAGNOSTIC ITEM 3: Diagnose shorts between CAN_H and L lines

Scheme 95

Scheme 96

1. The wiring harness may be defective [a short between CAN_H and CAN_L line, open circuit between the data link connector and the joint connector (3) or open circuit between the combination meter connector and the joint connector (3)] NOTE: The scan tool MB991958 cannot receive all the periodically sent data from each ECU by the open circuit of harness between the data link connector and the joint connector (3). In addition, the scan tool MB991958 measures the voltage itself and shows 2.5 volts due to the open circuit of harness. Therefore, it is judged as a short between CAN_H and CAN_L line.
2. The connector may be defective (short in the connector)
3. Each ECU may be defective (short between CAN_H and CAN_L line)

Required Special Tools

1. MB991223: Harness Set
2. MB992006: Extra fine probe
3. MB991970: ABS Check Harness

Scheme 97

Scheme 98

Scheme 99

Scheme 100

Scheme 101

Scheme 102

Scheme 103

Scheme 104

Scheme 105

Scheme 106

Scheme 107

Scheme 108

Scheme 109

Scheme 110

Scheme 111

Scheme 112

Scheme 113

Scheme 114

Scheme 115

Scheme 116

Scheme 117

Scheme 118

Scheme 119

Scheme 120

Scheme 121

Scheme 122

1. STEP 1. Check joint connector (3) C-03 and intermediate connector C-24. CAUTION: The strand end of the twisted wire should be within 10 cm (4.0 inches) from the connector. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). Visually check if there is a short between lines due to the foreign obstacles or deformation of short pin in the connector. Q: Is the check result normal? YES: Go to Step 2. NO: Repair the connector, or replace the joint connector (3).
2. STEP 2. Check the lines between the CAN_H and L lines of the front wiring harness for a short circuit. Measure the resistance at intermediate connector C-24. CAUTION: A digital multimeter should be used. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). The test wiring harness should be used. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). CAUTION: Disconnect the negative battery terminal. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). Disconnect the negative battery terminal. Disconnect intermediate connector C-24, and measure the resistance at the male side (at front wiring harness side). Measure the resistance between intermediate connector terminals 11 and 12. OK: 120 +/- 20 ohms Q: Is the check result normal? YES: Go to Step 3. NO: Go to Step 12.
3. STEP 3. Check the CAN_H and L lines between joint connector (3) and the combination meter for a short circuit. Measure the resistance at joint connector (3) C-03. Disconnect the negative battery terminal. Disconnect joint connector (3) C-03, and measure the resistance at the wiring harness side of joint connector (3) C-03. Measure the resistance between joint connector (3) terminals 4 and 15. OK: 120 +/- 20 ohms Q: Is the check result normal? YES : Go to Step 4. NO : Go to Step 8 .
4. STEP 4. Check the CAN_H and L lines between joint connector (3) and the ETACS-ECU for a short circuit. Measure the resistance at joint connector (3) C-03. Disconnect the negative battery terminal. Disconnect joint connector (3) C-03, and measure the resistance at the wiring harness side of joint connector (3) C-03. Measure the resistance between joint connector (3) terminals 5 and 16. OK: 1 kohms or more Q: Is the check result normal? YES : Go to Step 5. NO : Go to Step 9 .
5. STEP 5. Check the CAN_H and L lines between joint connector (3) and the A/C-ECU for a short circuit. Measure the resistance at joint connector (3) C-03. Disconnect the negative battery terminal. Disconnect joint connector (3) C-03, and measure the resistance at the wiring harness side of joint connector (3) C-03. Measure the resistance between joint connector (3) terminals 6 and 17. OK: 1 kohms or more Q: Is the check result normal? YES : Go to Step 6. NO : Go to Step 10 .
6. STEP 6. Check the CAN_H and L lines between joint connector (3) and the SRS-ECU for a short circuit. Measure the resistance at joint connector (3) C-03. Disconnect the negative battery terminal. Disconnect joint connector (3) C-03, and measure the resistance at the wiring harness side of joint connector (3) C-03. Measure the resistance between joint connector (3) terminals 3 and 14. OK: 1 kohms or more Q: Is the check result normal? YES : Go to Step 7. NO : Go to Step 11 .
7. STEP 7. Check the CAN_H and L lines between joint connector (3) and the data link connector for a short circuit. Measure the resistance at joint connector (3) C-03. Disconnect the negative battery terminal. Disconnect joint connector (3) C-03, and measure the resistance at the wiring harness side of joint connector (3) C-03. Measure the resistance between joint connector (3) terminals 7 and 18. OK: 1 kohms or more Q: Is the check result normal? YES : Repair the wiring harness between joint connector (3) and the intermediate connector. NO : Repair the wiring harness between joint connector (3) and the data link connector.
8. STEP 8. Check the combination meter for short circuit. Measure the resistance at combination meter connector C-04. NOTE: The failure could be caused by the open circuit of harness between combination meter and joint connector (3), therefore, check the open circuit as well as the short. Disconnect the negative battery terminal. Disconnect combination meter C-04, and measure the resistance at the component side of combination meter connector C-04. Measure the resistance between combination meter connector terminals 3 and 4. OK: 120 +/- 20 ohms Q: Is the check result normal? YES : Check the combination meter connector, and repair if necessary. Repair the open circuit of harness between the joint connector (3) and the combination meter connector or the short between lines if the combination meter connector is normal. NO : Check the combination meter connector, and repair if necessary. If the combination meter connector is in good condition, replace the combination meter.
9. STEP 9. Check the ETACS-ECU for short circuit. Measure the resistance at ETACS-ECU connector C-218. Disconnect the negative battery terminal. Disconnect ETACS-ECU connector C-218, and measure the resistance at the component side of ETACS-ECU connector C-218. Measure the resistance between ETACS-ECU connector terminals 72 and 73. OK: 1 kohms or more Q: Is the check result normal? YES: Check the ETACS-ECU connector, and repair if necessary. If the ETACS-ECU connector is in good condition, repair the wiring harness between joint connector (3) and the ETACS-ECU connector. NO: Check the ETACS-ECU connector, and repair if necessary. If the ETACS-ECU connector is in good condition, replace the ETACS-ECU. When the ETACS-ECU is replaced, register the encrypted code. Refer to «ENCRYPTED CODE REGISTRATION CRITERIA TABLE»(ref-241292-S39211918422006081100000).
10. STEP 10. Check the A/C-ECU for short circuit. Measure the resistance at A/C-ECU connector C-14 < manual air conditioning system > or C-15 < automatic air conditioning system >. CAUTION: A digital multimeter should be used. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). Disconnect the negative battery terminal. Disconnect A/C-ECU connector C-14 < manual air conditioning system > or C-15 < automatic air conditioning system >, and measure the resistance at the component side of A/C-ECU connector C-14 < manual air conditioning system > or C-15 < automatic air conditioning system >. Measure the resistance between A/C-ECU connector terminals 5 and 6. < manual air conditioning system > OK: 1 kohms or more Measure the resistance between A/C-ECU connector terminals 14 and 15. < automatic air conditioning system > OK: 1 kohms or more Q: Is the check result normal? YES: Check the A/C-ECU connector, and repair if necessary. If the A/C-ECU connector is in good condition, repair the wiring harness between joint connector (3) and the A/C-ECU connector. NO: Check the A/C-ECU connector, and repair if necessary. If the A/C-ECU connector is in good condition, replace the A/C-ECU.
11. STEP 11. Check the SRS-ECU for short circuit. Measure the resistance at SRS-ECU connector C-123. Disconnect the negative battery terminal. Disconnect SRS-ECU connector C-123, and measure the resistance at the component side of SRS-ECU connector C-123. Measure the resistance between SRS-ECU connector terminals 32 and 43. OK: 1 kohms or more Q: Is the check result normal? YES : Check the SRS-ECU connector, and repair if necessary. If the SRS-ECU connector is in good condition, repair the wiring harness between joint connector (3) and SRS-ECU connector. NO : Check the SRS-ECU connector, and repair if necessary. If the SRS-ECU connector is in good condition, replace the SRS-ECU.
12. STEP 12. Check the ECM < M/T > or PCM < A/T > for short circuit. Measure the resistance at ECM < M/T > or PCM < A/T > connector B-18. Disconnect the negative battery terminal. Disconnect ECM < M/T > or PCM < A/T > connector B-18, and measure the resistance at the component side of ECM < M/T > or PCM < A/T > connector B-18. Measure the resistance between ECM < M/T > or PCM < A/T > connector terminals 17 and 18. OK: 120 +/- 20 ohms Q: Is the check result normal? YES: Check the ECM < M/T > or PCM < A/T > connector, and repair if necessary. If the ECM < M/T > or PCM < A/T > connector is in good condition, go to Step 13. NO: Check the ECM < M/T > or PCM < A/T > connector, and repair if necessary. If the ECM < M/T > or PCM < A/T > connector is in good condition, replace the ECM < M/T > or PCM < A/T >. When the ECM < M/T > or PCM < A/T > is replaced, register the encrypted code. Refer to «ENCRYPTED CODE REGISTRATION CRITERIA TABLE»(ref-241292-S39211918422006081100000).
13. STEP 13. Check the ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > for short circuit. Measure the resistance at ABS-ECU connector A-02 < vehicles without traction control system > or ABS/TCL-ECU connector A-03 < vehicles with traction control system >. Disconnect the negative battery terminal. Disconnect ABS-ECU connector A-02 < vehicles without traction control system > or ABS/TCL-ECU connector A-03 < vehicles with traction control system >, and measure the resistance at the component side of ABS-ECU connector A-02 < vehicles without traction control system > or ABS/TCL-ECU connector A-03 < vehicles with traction control system >. Measure the resistance between ABS-ECU connector terminals 2 and 8. < vehicles without traction control system > OK: 1 kohms or more Measure the resistance between ABS/TCL-ECU connector terminals 13 and 27. < vehicles with traction control system > OK: 1 kohms or more Q: Is the check result normal? YES : Check the ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > connector, and repair if necessary. If the ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > connector is in good condition, go to Step 14. NO : Check the ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > connector, and repair if necessary. If the ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > connector is in good condition, replace the ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system >.
14. STEP 14. Check the CAN_L and H lines between the ECM < M/T > or PCM < A/T > connector and the ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > connector for a short circuit. Measure the resistance at ABS-ECU connector A-02 < vehicles without traction control system > or ABS/TCL-ECU connector A-03 < vehicles with traction control system >. Disconnect the negative battery terminal. Disconnect ECM connector < M/T > or PCM connector < A/T > B-18 and ABS-ECU connector A-02 < vehicles without traction control system > or ABS/TCL-ECU connector A-03 < vehicles with traction control system >, and measure the resistance at the harness side of ABS-ECU connector A-02 < vehicles without traction control system > or ABS/TCL-ECL connector A-03 < vehicles with traction control system >. Measure the resistance between ABS-ECU connector terminals 4 and 6. < vehicles without traction control system > OK: 1 kohms or more Measure the resistance between ABS/TCL-ECU connector terminals 11 and 15. < vehicles with traction control system > OK: 1 kohms or more Q: Is the check result normal? YES : Go to Step 15. NO : Repair the wiring harness between ECM connector < M/T > or PCM connector < A/T > and ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > connector.
15. STEP 15. Check the CAN_L and H lines between the ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > connector and the intermediate connector for a short circuit. Measure the resistance at intermediate connector C-24. Disconnect the negative battery terminal. Disconnect intermediate connector C-24 and ABS-ECU connector A-02 < vehicles without traction control system > or ABS/TCL-ECU connector A-03 < vehicles with traction control system >, and measure the resistance at the male side of intermediate connector C-24 (at front wiring harness side). Measure the resistance between intermediate connector terminals 11 and 12. OK: 1 kohms or more Q: Is the check result normal? YES : Repair the wiring harness between joint connector (3) and data link connector. NO : Repair the wiring harness between intermediate connector C-24 and ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > connector.

DIAGNOSTIC ITEM 4: Diagnose the terminator resistors

Scheme 123

1. The combination meter may be defective (malfunction of the terminator resistor)
2. The ECM < M/T > or PCM < A/T > may be defective (malfunction of the terminator resistor)
3. The wiring harness may be defective (larger resistance of harness between the combination meter and the ECM < M/T > or PCM < A/T >)

Required Special Tools

1. MB991223: Harness Set
2. MB992006: Extra fine probe

Scheme 124

Scheme 125

1. STEP 1. Check the terminator resistor inside the combination meter. Measure the resistance at combination meter connector C-04. CAUTION: A digital multimeter should be used. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). Disconnect combination meter C-04, and measure the resistance at the component side of combination meter connector C-04. Measure the resistance between combination meter connector terminals 3 and 4. OK: 120 +/- 20 ohms Q: Does the resistance measure 120 +/- 20 ohms? YES: Go to Step 2. NO: Replace the combination meter.
2. STEP 2. Check the terminator resistor inside the ECM < M/T > or PCM < A/T >. Measure the resistance at ECM < M/T > or PCM < A/T > connector B-18. Disconnect ECM < M/T > or PCM < A/T > connector B-18, and measure the resistance at the component side of ECM < M/T > or PCM < A/T > connector B-18. Measure the resistance between ECM < M/T > or PCM < A/T > connector terminals 17 and 18. OK: 120 +/- 20 ohms Q: Does the resistance measure 120 +/- 20 ohms? YES: Repair the wiring harness between combination meter connector and the ECM < M/T > or PCM < A/T > connector. NO: Replace the ECM < M/T > or PCM < A/T >. When the ECM < M/T > or PCM < A/T > is replaced, register the encrypted code. Refer to «ENCRYPTED CODE REGISTRATION CRITERIA TABLE»(ref-241292-S39211918422006081100000).

DIAGNOSTIC ITEM 5: Diagnose when the scan tool cannot receive the data sent by combination meter.

Scheme 126

1. The wiring harness may be defective [open circuit between combination meter and joint connector (3) ]
2. The connector may be defective [poor connection of joint connector (3) or combination meter connector]
3. Power supply circuit malfunction of the combination meter
4. The combination meter may be defective

Required Special Tools

1. MB991223: Harness Set
2. MB992006: Extra fine probe

Scheme 127

Scheme 128

Scheme 129

Scheme 130

Scheme 131

Scheme 132

1. STEP 1. Check joint connector (3) C-03 and combination meter connector C-04 for loose, corroded or damaged terminals, or terminals pushed back in the connector. Check the joint connector at the wiring harness side for loose, corroded or damaged terminals, or terminals pushed back in the connector, and also check the short pin behind the connector for corrosion, deformation and delamination. Q: Are joint connector (3) C-03 and combination meter connector C-04 in good condition? YES : Go to Step 2. NO : Repair the damaged parts. Replace the joint connector as necessary.
2. STEP 2. Check the CAN bus lines between joint connector (3) and the combination meter. Measure the resistance between joint connector (3) C-03 and combination meter connector C-04. CAUTION: A digital multimeter should be used. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). The test wiring harness should be used. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). Disconnect joint connector (3) C-03 and combination meter connector C-04, and measure the resistance between each wiring harness side connector. Measure the resistance between joint connector (3) terminal 4 and combination meter connector terminal 3. OK: 2 ohms or less Measure the resistance between joint connector (3) terminal 15 and combination meter connector terminal 4. OK: 2 ohms or less CAUTION: Strictly observe the specified wiring harness repair procedure. For details refer to «PRECAUTIONS ON HOW TO REPAIR THE CAN BUS LINES»(ref-241285-S35921930502006081100000). Q: Do all the resistances measure 2 ohms or less? YES: Go to Step 3. NO: Repair the wiring harness between joint connector (3) and the combination meter connector.
3. STEP 3. Check the terminator resistor inside the combination meter. Measure the resistance at combination meter connector C-04. Disconnect combination meter C-04, and measure the resistance at the component side of combination meter connector C-04. Measure the resistance between combination meter connector terminals 3 and 4. OK: 120 +/- 20 ohms Q: Does the resistance measure 120 +/- 20 ohms? YES: Refer to Chassis Electrical - Combination Meter - «INSPECTION PROCEDURES»(ref-241292-S04931418222006081100000). NO: Replace the combination meter.

DIAGNOSTIC ITEM 6: Diagnose when the scan tool cannot receive the data sent by ETACS-ECU.

Scheme 133

1. The wiring harness may be defective [open circuit between ETACS-ECU and joint connector (3)]
2. The connector may be defective [poor connection of joint connector (3) or ETACS-ECU connector]
3. Power supply circuit malfunction of the ETACS-ECU
4. The ETACS-ECU may be defective

Required Special Tools

1. MB991223: Harness Set
2. MB992006: Extra fine probe

Scheme 134

Scheme 135

Scheme 136

Scheme 137

Scheme 138

1. STEP 1. Check joint connector (3) C-03 and ETACS-ECU connector C-218 for loose, corroded or damaged terminals, or terminals pushed back in the connector. CAUTION: The strand end of the twisted wire should be within 10 cm (4.0 inches) from the connector. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). Check the joint connector at the wiring harness side for loose, corroded or damaged terminals, or terminals pushed back in the connector, and also check the short pin behind the connector for corrosion, deformation and delamination. Q: Are joint connector (3) C-03 and ETACS-ECU connector C-218 in good condition? YES: Go to Step 2. NO: Repair the damaged parts. Replace the joint connector as necessary.
2. STEP 2. Check the CAN bus lines between joint connector (3) and the ETACS-ECU. Measure the resistance between joint connector (3) C-03 and ETACS-ECU connector C-218. CAUTION: A digital multimeter should be used. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). The test wiring harness should be used. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). Disconnect joint connector (3) C-03 and ETACS-ECU connector C-218, and measure the resistances at the wiring harness sides of joint connector (3) C-03 and ETACS-ECU connector C-218. Measure the resistance between joint connector (3) terminal 5 and ETACS-ECU connector terminal 72. OK: 2 ohms or less Measure the resistance between joint connector (3) terminal 16 and ETACS-ECU connector terminal 73. OK: 2 ohms or less CAUTION: Strictly observe the specified wiring harness repair procedure. For details refer to «PRECAUTIONS ON HOW TO REPAIR THE CAN BUS LINES»(ref-241285-S35921930502006081100000). Q: Do all the resistances measure 2 ohms or less? YES: Diagnose the SWS. Refer to «SYMPTOM PROCEDURES»(/mitsubishi/eclipse/iv-2005-2008/remont/communication-devices/#simplified-wiring-system). NO: Repair the wiring harness between joint connector (3) and the ETACS-ECU connector.

DIAGNOSTIC ITEM 7: Diagnose when the scan tool cannot receive the data sent by A/C-ECU.

Scheme 139

1. The wiring harness may be defective [open circuit between A/C-ECU and joint connector (3)]
2. The connector may be defective [poor connection of joint connector (3) or A/C-ECU connector]
3. Power supply circuit malfunction of the A/C-ECU
4. The A/C-ECU may be defective

Required Special Tools

1. MB991223: Harness Set
2. MB992006: Extra fine probe

Scheme 140

Scheme 141

Scheme 142

Scheme 143

Scheme 144

Scheme 145

Scheme 146

Scheme 147

Scheme 148

1. STEP 1. Check joint connector (3) C-03 and A/C-ECU connector C-14 < manual air conditioning system > or C-15 < automatic air conditioning system > for loose, corroded or damaged terminals, or terminals pushed back in the connector. CAUTION: The strand end of the twisted wire should be within 10 cm (4.0 inches) from the connector. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). Check the joint connector at the wiring harness side for loose, corroded or damaged terminals, or terminals pushed back in the connector, and also check the short pin behind the connector for corrosion, deformation and delamination. Q: Are joint connector (3) C-03 and A/C-ECU connector C-14 < manual air conditioning system > or C-15 < automatic air conditioning system > in good condition? YES: Go to Step 2. NO: Repair the damaged parts. Replace the joint connector as necessary.
2. STEP 2. Check the CAN bus lines between joint connector (3) and the A/C-ECU. Measure the resistance between joint connector (3) C-02 and A/C-ECU connector C-10 < manual air conditioning system > or C-15 < automatic air conditioning system >. CAUTION: A digital multimeter should be used. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). The test wiring harness should be used. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). Disconnect joint connector (3) C-03 and A/C-ECU connector C-14 < manual air conditioning system > or C-15 < automatic air conditioning system >, and measure the resistances at the wiring harness sides of joint connector (3) C-03 and A/C-ECU connector C-14 < manual air conditioning system > or C-15 < automatic air conditioning system >. Measure the resistance between joint connector (3) terminal 6 and A/C-ECU connector terminal 5 < manual air conditioning system > or 15 < automatic air conditioning system >. OK: 2 ohms or less CAUTION: Strictly observe the specified wiring harness repair procedure. For details refer to «PRECAUTIONS ON HOW TO REPAIR THE CAN BUS LINES»(ref-241285-S35921930502006081100000). Measure the resistance between joint connector (3) terminal 17 and A/C-ECU connector terminal 6 < manual air conditioning system > or 14 < automatic air conditioning system >. OK: 2 ohms or less Q: Do all the resistances measure 2 ohms or less? YES: Diagnose the air conditioning system. Refer to Manual A/C diagnosis «SYMPTOM PROCEDURES»(ref-241288-S40387139372006081100000) < manual air conditioning system > or Auto A/C diagnosis «SYMPTOM PROCEDURES»(ref-241328-S40977281592006081100000) < automatic air conditioning system >. NO: Repair the wiring harness between joint connector (3) and the A/C-ECU connector.

DIAGNOSTIC ITEM 8: Diagnose when the scan tool cannot receive the data sent by SRS-ECU.

Scheme 149

1. The wiring harness may be defective [open circuit between SRS-ECU and joint connector (3)]
2. The connector may be defective [poor connection of joint connector (3) or SRS-ECU connector]
3. Power supply circuit malfunction of the SRS-ECU
4. The SRS-ECU may be defective

Required Special Tools

1. MB991223: Harness Set
2. MB992006: Extra fine probe

Scheme 150

Scheme 151

Scheme 152

Scheme 153

Scheme 154

Scheme 155

1. STEP 1. Check joint connector (3) C-03 and SRS-ECU connector C-123 for loose, corroded or damaged terminals, or terminals pushed back in the connector. CAUTION: The strand end of the twisted wire should be within 10 cm (4.0 inches) from the connector. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). Check the joint connector at the wiring harness side for loose, corroded or damaged terminals, or terminals pushed back in the connector, and also check the short pin behind the connector for corrosion, deformation and delamination. Q: Are joint connector (3) C-03 and SRS-ECU connector C-123 in good condition? YES: Go to Step 2. NO: Repair the damaged parts. Replace the joint connector as necessary.
2. STEP 2. Check the CAN bus lines joint connector (3) and the SRS-ECU. Measure the resistance between joint connector (3) C-03 and SRS-ECU connector C-123. CAUTION: A digital multimeter should be used. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). The test wiring harness should be used. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). CAUTION: Disconnect the negative battery terminal. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). Disconnect the negative battery terminal. Disconnect joint connector (3) C-03 and SRS-ECU connector C-123, and measure the resistance between the wiring harness side connector of SRS-ECU connector C-123 and joint connector (3) C-03. Measure the resistance between joint connector (3) terminal 3 and SRS-ECU connector terminal 32. OK: 2 ohms or less Measure the resistance between joint connector (3) terminal 14 and SRS-ECU connector terminal 43. OK: 2 ohms or less CAUTION: Strictly observe the specified wiring harness repair procedure. For details refer to «PRECAUTIONS ON HOW TO REPAIR THE CAN BUS LINES»(ref-241285-S35921930502006081100000). Q: Do all the resistances measure 2 ohms or less? YES: Diagnose the supplemental restraint system. Refer to «DIAGNOSTIC TROUBLE CODE CHART»(ref-241293-S32081257212006081100000). NO: Repair the wiring harness between joint connector (3) and the SRS-ECU connector.

DIAGNOSTIC ITEM 9: Diagnose when the scan tool cannot receive the data sent by the ECM < M/T > or the PCM < A/T >.

Scheme 156

1. The wiring harness may be defective (open circuit between ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > and ECM < M/T > or PCM < A/T >)
2. The connector may be defective (poor connection of ECM < M/T > or PCM < A/T > connector and ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > connector)
3. Power supply circuit malfunction of the ECM < M/T > or PCM < A/T >
4. The ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > may be defective (internal open circuit)
5. The ECM < M/T > or PCM < A/T > may be defective

Required Special Tools

1. MB991223: Harness Set
2. MB992006: Extra fine probe
3. MB991970: ABS Check Harness

Scheme 157

Scheme 158

Scheme 159

Scheme 160

Scheme 161

Scheme 162

Scheme 163

Scheme 164

Scheme 165

Scheme 166

1. STEP 1. Check ABS-ECU connector A-02 < vehicles without traction control system > or ABS/TCL-ECU connector A-03 < vehicles with traction control system > and ECM connector < M/T > or PCM connector < A/T > B-18 for loose, corroded or damaged terminals, or terminals pushed back in the connector. CAUTION: The strand end of the twisted wire should be within 10 cm (4.0 inches) from the connector. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). Q: Are ABS-ECU connector A-02 < vehicles without traction control system > or ABS/TCL-ECU connector A-03 < vehicles with traction control system > and ECM connector < M/T > or PCM connector < A/T > B-18 in good condition? YES: Go to Step 2. NO: Repair the damaged parts.
2. STEP 2. Check the CAN bus lines between the ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > and the ECM < M/T > or PCM < A/T >. Measure the resistance between ABS-ECU connector A-02 < vehicles with traction control system > or ABS/TCL-ECU connector < vehicles with traction control system > and ECM connector < M/T > or PCM connector < A/T > B-18. CAUTION: A digital multimeter should be used. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). The test wiring harness should be used. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). Disconnect ABS-ECU connector A-02 < vehicles without traction control system > or ABS/TCL-ECU connector A-03 < vehicles with traction control system > and ECM < M/T > or PCM connector < A/T > B-18, and measure the resistance between each wiring harness side connector. Measure the resistance between ABS-ECU connector < vehicles without traction control system > terminal 4 and ECM connector < M/T > or PCM connector < A/T > terminal 17. OK: 2 ohms or less Measure the resistance between ABS-ECU connector < vehicles without traction control system > terminal 6 and ECM connector < M/T > or PCM connector < A/T > terminal 18. OK: 2 ohms or less Measure the resistance between ABS/TCL-ECU connector < vehicles with traction control system > terminal 11 and ECM connector < M/T > or PCM connector < A/T > terminal 17. OK: 2 ohms or less Measure the resistance between ABS/TCL-ECU connector < vehicles with traction control system > terminal 15 and ECM connector < M/T > or PCM connector < A/T > terminal 18. OK: 2 ohms or less CAUTION: Strictly observe the specified wiring harness repair procedure. For details refer to «PRECAUTIONS ON HOW TO REPAIR THE CAN BUS LINES»(ref-241285-S35921930502006081100000). Q: Do all the resistances measure 2 ohms or less? YES: Go to Step 3. NO: Repair the wiring harness between the ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > connector and the ECM connector < M/T > or PCM connector < A/T >.
3. STEP 3. Check the CAN bus lines inside the ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system >. Measure the resistance at ABS-ECU connector A-02 < vehicles without traction control system > or ABS/TCL-ECU connector A-03 < vehicles with traction control system >. Disconnect ABS-ECU connector A-02 < vehicles without traction control system > or ABS/TCL-ECU A-03 < vehicles with traction control system >, and measure the resistance at the component side of ABS-ECU connector A-02 < vehicles without traction control system > or ABS/TCL-ECU connector A-03 < vehicles with traction control system >. Measure the resistance between ABS-ECU connector < vehicles without traction control system > terminals 2 and 4. OK: 2 ohms or less Measure the resistance between ABS-ECU connector < vehicles without traction control system > terminals 8 and 6. OK: 2 ohms or less Measure the resistance between ABS/TCL-ECU connector < vehicles with traction control system > terminals 11 and 27. OK: 2 ohms or less Measure the resistance between ABS/TCL-ECU connector < vehicles with traction control system > terminals 13 and 15. OK: 2 ohms or less Q: Do all the resistances measure 2 ohms or less? YES : Diagnose the engine. Refer to MFI diagnosis «INSPECTION PROCEDURE 2: SCAN TOOL COMMUNICATION WITH ECM < M/T > OR PCM < A/T > IS NOT POSSIBLE.»(/mitsubishi/eclipse/iv-2005-2008/remont/testing-diagnostics/#multiport-fuel-injection-24l) < 2.4L engine > or MFI diagnosis «INSPECTION PROCEDURE 2: SCAN TOOL COMMUNICATION WITH ECM < M/T > OR PCM < A/T > IS NOT POSSIBLE.»(/mitsubishi/eclipse/iv-2005-2008/remont/testing-diagnostics/#multiport-fuel-injection-38l) < 3.8L engine >. NO : Replace the ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system >.

DIAGNOSTIC ITEM 10: Diagnose when the scan tool cannot receive the data sent by ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system >.

1. The wiring harness may be defective [open circuit between ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > and joint connector (3) ]
2. The connector may be defective [poor connection of joint connector (3) or ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > connector]
3. Power supply circuit malfunction of ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system >
4. The ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > may be defective (internal open circuit)
5. The ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > may be defective

Diagnose the ABS system. Refer to ABS diagnosis INSPECTION PROCEDURE 2: ABS-ECU POWER SUPPLY CIRCUIT SYSTEM.

DIAGNOSTIC ITEM 11: Diagnose when the scan tool cannot receive the data sent by the ECM < M/T > or the PCM < A/T > and ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system >.

Scheme 167

1. The wiring harness may be defective [open circuit between ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > and joint connector (3) ]
2. The connector may be defective [poor connection of joint connector (3) or ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > connector]
3. The ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > may be defective (internal open circuit)

Required Special Tools

1. MB991223: Harness Set
2. MB992006: Extra fine probe
3. MB991970: ABS Check Harness

Scheme 168

Scheme 169

Scheme 170

Scheme 171

Scheme 172

Scheme 173

Scheme 174

Scheme 175

Scheme 176

Scheme 177

Scheme 178

Scheme 179

Scheme 180

1. STEP 1. Check joint connector (3) C-03 and ABS-ECU connector A-02 < vehicles without traction control system > or ABS/TCL-ECU connector A-03 < vehicles with traction control system > for loose, corroded or damaged terminals, or terminals pushed back in the connector. CAUTION: The strand end of the twisted wire should be within 10 cm (4.0 inches) from the connector. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). Q: Are joint connector (3) C-03 and ABS-ECU connector A-02 < vehicles without traction control system > or ABS/TCL-ECU connector A-03 < vehicles with traction control system > in good condition? YES: Go to Step 2. NO: Repair the damaged parts. Replace the joint connector as necessary.
2. STEP 2. Check the CAN bus lines between intermediate connector C-29 and joint connector (3). Measure the resistance between intermediate connector C-24 and joint connector (3) C-03. CAUTION: A digital multimeter should be used. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). The test wiring harness should be used. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). Disconnect intermediate connector C-24 and joint connector (3) C-03, and measure the resistance between the wiring harness side connector of joint connector (3) C-03 and the male side connector of intermediate connector C-24 (at front wiring harness side). Turn the ignition switch to the "LOCK" (OFF) position. CAUTION: Disconnect the negative battery terminal. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). Disconnect the negative battery terminal. Measure the resistance between intermediate connector terminal 11 and joint connector (3) terminal 9. OK: 2 ohms or less Measure the resistance between intermediate connector terminal 12 and joint connector (3) terminal 20 OK: 2 ohms or less CAUTION: Strictly observe the specified wiring harness repair procedure. For details refer to «PRECAUTIONS ON HOW TO REPAIR THE CAN BUS LINES»(ref-241285-S35921930502006081100000). Q: Do all the resistances measure 2 ohms or less? YES: If all the resistances measure 2 ohms or less, go to Step 3. NO: If either of the resistances measures more than 2 ohms or all the resistances measure more than 2 ohms, repair the wiring harness between intermediate connector C-29 and the joint connector (3).
3. STEP 3. Check the CAN bus lines between intermediate connector C-29 and the ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system >. Measure the resistance between intermediate connector C-24 and ABS-ECU connector A-02 < vehicles without traction control system > or ABS/TCL-ECU connector A-03 < vehicles with traction control system >. CAUTION: A digital multimeter should be used. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). The test wiring harness should be used. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). Disconnect intermediate connector C-24 and ABS-ECU connector A-02 < vehicles without traction control system > or ABS/TCL-ECU connector A-03 < vehicles with traction control system >, and measure the resistance between the wiring harness side connector of ABS-ECU connector A-02 < vehicles without traction control system > or ABS/TCL-ECU connector A-03 < vehicles with traction control system > and the male side connector of intermediate connector C-24 (at front wiring harness side). Turn the ignition switch to the "LOCK" (OFF) position. CAUTION: Disconnect the negative battery terminal. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). Disconnect the negative battery terminal. Measure the resistance between intermediate connector terminal 11 and ABS-ECU connector terminal 2. < vehicles without traction control system > OK: 2 ohms or less Measure the resistance between intermediate connector terminal 12 and ABS-ECU connector terminal 8. < vehicles without traction control system > OK: 2 ohms or less Measure the resistance between intermediate connector terminal 11 and ABS/TCL-ECU connector terminal 27. < vehicles with traction control system > OK: 2 ohms or less Measure the resistance between intermediate connector terminal 12 and ABS/TCL-ECU connector terminal 13. < vehicles with traction control system > OK: 2 ohms or less CAUTION: Strictly observe the specified wiring harness repair procedure. For details refer to «PRECAUTIONS ON HOW TO REPAIR THE CAN BUS LINES»(ref-241285-S35921930502006081100000). Q: Do all the resistances measure 2 ohms or less? YES: If all the resistances measure 2 ohms or less, go to Step 4. NO: If either of the resistances measures more than 2 ohms or all the resistances measure more than 2 ohms, repair the wiring harness between intermediate connector C-29 and the ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system > connector.
4. STEP 4. Check the CAN bus lines inside the ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system >. Measure the resistance at ABS-ECU connector A-02 < vehicles without traction control system > or ABS/TCL-ECU connector A-03 < vehicles with traction control system >. Disconnect ABS-ECU connector A-02 < vehicles without traction control system > or ABS/TCL-ECU A-03 < vehicles with traction control system >, and measure the resistance at the component side of ABS-ECU connector A-02 < vehicles without traction control system > or ABS/TCL-ECU connector A-03 < vehicles with traction control system >. Measure the resistance between ABS-ECU connector < vehicles without traction control system > terminals 2 and 4. OK: 2 ohms or less Measure the resistance between ABS-ECU connector < vehicles without traction control system > terminals 8 and 6. OK: 2 ohms or less Measure the resistance between ABS/TCL-ECU connector < vehicles with traction control system > terminals 11 and 27. OK: 2 ohms or less Measure the resistance between ABS/TCL-ECU connector < vehicles with traction control system > terminals 13 and 15. OK: 2 ohms or less Q: Do all the resistances measure 2 ohms or less? YES : Intermittent malfunction. NO : Replace the ABS-ECU < vehicles without traction control system > or ABS/TCL-ECU < vehicles with traction control system >.

DIAGNOSTIC ITEM 12: Diagnose CAN bus lines thoroughly

Scheme 181

Scheme 182

1. Each ECU may be defective
2. The wiring harness may be defective
3. The connector may be defective

Required Special Tools

1. MB991223: Harness Set
2. MB992006: Extra Fine Probe
3. MB991958: Scan Tool (MUT-III Sub Assembly) MB991824: Vehicle Communication Interface (V.C.I.) MB991827: MUT-III USB Cable MB991910: MUT-III Main Harness A
4. MB991970: ABS Check Harness

Scheme 183

Scheme 184

Scheme 185

Scheme 186

1. STEP 1. Check the CAN bus lines at the data link connector. Measure the resistance at the data link connector C-125. CAUTION: A digital multimeter should be used. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). The test wiring harness should be used. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). CAUTION: Disconnect the negative battery terminal. For details refer to «SERVICE PRECAUTIONS»(ref-241285-S19445224772006081100000). Disconnect the negative battery terminal. Measure the resistance at the data link connector. Measure the resistance between data link connector terminals 6 and 14. OK: 60 +/- 10 ohms Q: How much resistance is measured? YES (60 +/- 10 ohms): Go to Step 2. NO (2 ohms or less or 200 ohms or more): Diagnostic Item 3: Check the CAN_H and L lines for a short circuit. Refer to «DIAGNOSTIC ITEM 3: DIAGNOSE SHORTS BETWEEN CAN_H AND L LINES»(ref-241285-S10010173262006081100000). NO (other than them resistance): Diagnostic Item 4: Diagnose terminator resistors at both ends. Refer to «DIAGNOSTIC ITEM 4: DIAGNOSE THE TERMINATOR RESISTORS»(ref-241285-S25848671062006081100000).
2. STEP 2. Using scan tool MB991958, diagnose the CAN bus line (Disconnect combination meter connector C-04, and check the combination meter system). Disconnect combination meter connector C-04. CAUTION: To 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 to the data link connector. Diagnose CAN bus lines, and check if scan tool MB991958 screen is as shown in the illustration. Q: Does scan tool MB991958 screen correspond to the illustration? YES: Go to Step 3. NO: Refer to «DIAGNOSTICS ITEM 5: DIAGNOSE WHEN THE SCAN TOOL CANNOT RECEIVE THE DATA SENT BY COMBINATION METER»(ref-241285-S27885840022006081100000).
3. STEP 3. Using scan tool MB991958, diagnose the CAN bus line (Disconnect ETACS-ECU connector C-218, and check the ETACS-ECU system). Disconnect ETACS-ECU connector C-218. Diagnose CAN bus lines, and check if scan tool MB991958 screen is as shown in the illustration. Q: Does scan tool MB991958 screen correspond to the illustration? YES: Go to Step 4. NO: Refer to «DIAGNOSTICS ITEM 6: DIAGNOSE WHEN THE SCAN TOOL CANNOT RECEIVE THE DATA SENT BY ETACS-ECU»(ref-241285-S12493765492006081100000).
4. STEP 4. Using scan tool MB991958, diagnose the CAN bus line (Disconnect A/C-ECU connector C-14 < manual air conditioning system > or C-15 < automatic air conditioning system >, and check the A/C-ECU system). Disconnect A/C-ECU connector C-14 < manual air conditioning system > or C-15 < automatic air conditioning system >. Diagnose CAN bus lines, and check if scan tool MB991958 screen is as shown in the illustration. Q: Does scan tool MB991958 screen correspond to the illustration? YES: Go to Step 5. NO: Refer to «DIAGNOSTICS ITEM 7: DIAGNOSE WHEN THE SCAN TOOL CANNOT RECEIVE THE DATA SENT BY A/C-ECU»(ref-241285-S04793643222006081100000).
5. STEP 5. Using scan tool MB991958, diagnose the CAN bus line (Disconnect SRS-ECU connector C-123, and check the supplemental restraint system). Disconnect SRS-ECU connector C-123. Diagnose CAN bus lines, and check if scan tool MB991958 screen is as shown in the illustration. Q: Does scan tool MB991958 screen correspond to the illustration? YES: Go to Step 6. NO: Refer to «DIAGNOSTICS ITEM 9: DIAGNOSE WHEN THE SCAN TOOL CANNOT RECEIVE THE DATA SENT BY SRS-ECU»(ref-241285-S04191979172006081100000).
6. STEP 6. Using scan tool MB991958, diagnose the CAN bus line (Disconnect ECM connector < M/T > or PCM connector < A/T > B-18, and check the ECM system < M/T > or the PCM system < A/T >). Disconnect ECM connector < M/T > or PCM connector < A/T > B-18. Diagnose CAN bus lines, and check if scan tool MB991958 screen is as shown in the illustration. Q: Does scan tool MB991958 screen correspond to the illustration? YES: Refer to «DIAGNOSTICS ITEM 11: DIAGNOSE WHEN THE SCAN TOOL CANNOT RECEIVE THE DATA SENT BY THE ECM < M/T > OR THE PCM < A/T > AND ABS-ECU < VEHICLES WITHOUT TRACTION CONTROL SYSTEM > OR ABS/TCL-ECU < VEHICLES WITH TRACTION CONTROL SYSTEM >»(ref-241285-S20943324662006081100000). NO: Refer to «DIAGNOSTICS ITEM 9: DIAGNOSE WHEN THE SCAN TOOL CANNOT RECEIVE THE DATA SENT BY THE ECM < M/T > OR THE PCM < A/T >»(ref-241285-S04191979172006081100000).

CAN CMMUNICATION-RELATED DTC CODE (U CODE) TABLE

CAN CMMUNICATION-RELATED DTC CODE (U CODE) TABLE

See also:
• SYMPTOM PROCEDURES
• INSPECTION PROCEDURE 2: SCAN TOOL COMMUNICATION WITH ECM < M/T > OR PCM < A/T > IS NOT POSSIBLE.
• INSPECTION PROCEDURE 2: SCAN TOOL COMMUNICATION WITH ECM < M/T > OR PCM < A/T > IS NOT POSSIBLE.