Several control units are applied to electronically controlled vehicles. These units perform each control with informations from various sensors. Thus, sharing signal information from sensors is needed, so CAN communication type whose communication speed is high and insensitive to electrical noise by spark generation is adopted to controlling power-train(TCM, ECM, CLUSTER,VDC,4WD,EAS,SAS, EPS)
CAN communication consists of CAN BUS HIGH, CAN BUS LOW and two 120Ω resistances in circuit.
TCM set this code If detected error in CAN communication line. (MIL OFF)
Item | Detecting Condition | Possible Cause |
DTC Strategy | ● Check function | ● CAN communication line open of TCM side ● CAN communication line short of TCM side ● ECM ● CLUSTER ● Mechatronics(E-module + Valvebody) |
Enable Conditions | ● Battery voltage > 9V ● 0.5 second after IG ON | |
Threshold Value | ● CAN BUS가 OFF (Not properly work CAN BUS) ● CAN time-out | |
Diagnostic Time | ● 0.56 second | |
Fail Safe | ● Maximum line pressure control (D : 14kg/㎠, R : 20kg/㎠) ● Vehicle speed is subtituted wheel speed ● Release "Shift lock" ● Maintain present gear position at fault detecting. ● Fixed at 3rd gear after stop ● No control Torque convertor clutch ● No learning control (Priority : 3) |
Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
Has a problem been found?
 | ▶ Fault is intermittent caused by poor contact in the sensor's and/or TCM(PCM)'s connector or was repaired and TCM(PCM) memory was not cleared. Throughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration or damage.Repair or replace as necessary and go to "Verification Vehicle Repair" procedure |
 | ▶ Go to "W/Harness Inspection" procedure |
IG KEY OFF .
Connect ECM, TCM, 4WD, VDC(ABS/TCS), EAS, SAS and CLUSTER connector.
Measure resistance between #3 terminal and #11 terminal of "DLC".
Specification : Approx. 60 Ω
Is measured resistance within specifications ?
| ▶ Check TCM connector as necessary and then go to "Verification of Vehicle Repair" procedure. |
| ▶ Go to next procedure. |
IG KEY OFF .
Disconnect ECM connector.
Measure resistance between #3 terminal and #11 terminal of "DLC"..
Specification : Approx. 120 Ω
Is measured resistance within specifications ?
| ▶ Go to next procedure. |
| ▶ Check TCM connector as necessary and then go to "Verification of Vehicle Repair" procedure. ▶ Perform open/short test with CAN communication line of TCM and ECM. ▶ Perform resistance test with CAN communication line of ECM. |
IG KEY OFF .
Disconnect CLUSTER connector.
Measure resistance between #3 terminal and #11 terminal of "DLC".
Specification : Approx. 120 Ω
Is measured resistance within specifications ?
| ▶ Go to next procedure. |
| ▶ Check BMS connector as necessary and then go to "Verification of Vehicle Repair" procedure. ▶ Perform open/short test with CAN communication line of TCM and CLUSTER. ▶ Perform resistance test with CAN communication line of CLUSTER. |
.IG KEY OFF .
Connect TCM, ECM, CLUSTER connector.
Measure voltage between TCM CAN HIGH and CAN LOW terminal.
Specification : Approx. 2.3V
Is measured voltage within specifications ?
| ▶ Go to next procedure. |
| ▶ Repair shorted circuit in CAN communication line as necessary and then go to "Verification of Vehicle Repair" procedure. |
IG KEY OFF .
Disconnector TCM, ECM and CLUSTER connector.
Measure resistance between TCM CAN HIGH or CAN LOW and CLUSTER CAN HIGH or CAN LOW terminal.
Specification : Approx. 0Ω
Is measured resistance within specifications ?
| ▶ Go to next procedure. |
| ▶ Repair opened circuit in CAN communication line of CLUSTER as necessary and then go to "Verification of Vehicle Repair" procedure. |
IG KEY OFF .
Disconnector TCM, ECM and CLUSTER connector.
Measure resistance between ECM CAN HIGH or CAN LOW and CLUSTER CAN HIGH or CAN LOW terminal.
Specification : Approx. 0Ω
Is measured resistance within specifications ?
| ▶ Go to next procedure. |
| ▶ Repair opened circuit in CAN communication line of ECM as necessary and then go to "Verification of Vehicle Repair" procedure. |
IG KEY OFF .
Disconnector TCM, ECM and CLUSTER connector.
Measure resistance between ECM CAN HIGH or CAN LOW and CLUSTER CAN HIGH or CAN LOW terminal.
Specification : Approx. 120Ω
Is measured resistance within specifications ?
| ▶ Check poor connection between TCM and other component Rapiar as necessary and then go to "Verification of Vehicle Repair" procedure. |
| ▶ Substitute with a known-good TCM or CLUSTER and check for proper operation. If the problem is corrected, replace PCM/TCM as necessary and then go to "Verification of Vehicle Repair" procedure. |
After a repair, it is essential to verify that the fault has been corrected.
Connect scantool and select "Diagnostic Trouble Codes(DTCs)" mode.
Using a scan tool, Clear DTC.
Operate the vehicle within DTC Enable conditions in General information.
Are any DTCs present ?
| ▶ Go to the applicable troubleshooting procedure |
| ▶ System performing to specification at this time. |
