3.
Monitor signal waveform between terminal 3 & 4 of TCM harness connector and chassis ground.
A communication line exists between the Engine Control Module(ECM) and the Transaxle Control Module(TCM). The communication is through a Control Area Network(CAN). Without CAN communication, an independent pin and wiring is needed to receive a sensor information from a ECM. The more information to be communicated, the more wirings is required. In case of CAN communication type, all the information need to be communicated among control modules such as ECM and TCM use CAN lines.
After clearing the DTC, check the malfunction of TCM and 4WD ECM, if the DTC sets again. This code may set if there is no signal to 4WD ECM.
Item | Detecting Condition & Fail Safe | Possible Cause |
DTC Strategy | ● ECU-ITM Communication Line, or ECU side malfunction | ● ECM, 4WD ECM connector looseness and poor terminal to wire connection. ● CAN HIGH/LOW circuit open/short. ● ECM malfunction. ● 4WD ECM malfunction. |
Enable Conditions | ● IG SW ON ● No actuator test ● No holding ● No fail in input/output speed sensors ● Battery voltage ≥ 10V ● Engine speed ＞ Approx. 260 rpm | |
Threshold Value | ● Loss of Signal | |
Diagnostic Time | ● 1 Sec. | |
Fail safe | ● COMMUNICATION : STOP TCM transmitting ● LOGIC : NO INTELLIGENT SHIFT, NO hydraulic control learning, NO TORQUE RETARD |
IG KEY ON, ENG ON
TCM or 4WD ECM connector : Connect.
Monitor signal waveform between terminal 3 & 4 of TCM harness connector and chassis ground.
Many malfunctions in the electrical system may be caused from poor harness and terminals. These faults can 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?
▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure.
▶ Go to the next procedure.
ECM-TCM communication line open inspection
IG KEY OFF, ENG OFF
ECM connector and TCM connector: Disconnect.
Measure resistance between terminals 10 of the ECM harness connector and 3 of the TCM harness connector.
Measure resistance between terminals 9 of the ECM harness connector and 4 of the TCM harness connector.
Specification : Approx. 0Ω
Is resistance display near the specified value?
▶ Check if ECM-TCM communication line is short.
▶ Repair open circuit of CAN Low comm. Line.
ECM-TCM communication line short to ground inspection
IG KEY OFF, ENG OFF
TCM connector, ECM connector, 4WD ECM connector and TCS(or ESP) connector: Disconnect.
Measure resistance between terminal 4 of TCM harness connector and chassis ground.
Measure resistance between terminal 3 of TCM harness connector and chassis ground.
Specification : Approx. ∞Ω
Is resistance display near the specified value?
▶ Go to the "Component inspection".
▶ Repair ground to short circuit of CAN Low comm. Line.
▶ If problem is solved, go to the "Verification of Vehicle Repair".
TCM component inspection
IG KEY OFF, ENG OFF
Measure resistance between the terminal 3 and 4 with the specification below.
Specification: Without TCS, 4WD system
※ ECM connector and TCM connector: Connect -＞ 60Ω ± 1Ω
※ ECM connector: Disconnect and TCM connector: Connect -＞120Ω ± 2Ω
※ ECM connector: Connect and TCM connector: Disconnect -＞120Ω ± 2Ω
Specification: With TCS, 4WD system
※ ECM connector and TCM connector: Connect -＞120Ω ± 2Ω
Is resistance display near the specified value?
▶ Check if ECM-TCM communication line is short to ground.
▶ Check if ECM-TCM communication line is open.
ECM waveform inspection
IG KEY OFF, ENG OFF
TCM connector: Disconnect.
Connect the terminal 3 and 4 of TCM connector to a scan tool.
IG KEY ON
Is CAN Signal display near the specified value?
▶ Inspect TCM waveform.
▶ ECM communication signal malfunction - replace ECM.
▶ After checking 4WD ECM circuit, if any malfunctino is detected, replace 4WD ECM.
TCM waveform inspection
IG KEY OFF, ENG OFF
ECM connector: Disconnect.
Connect the terminal 9 and 10 of ECM connector to a scan tool.
IG KEY ON
Is CAN Signal display near the specified value?
▶ TCM is in a normal condition.
▶ TCM communication signal malfunction - replace TCM.
▶ After checking 4WD ECM circuit, if any malfunctino is detected, replace 4WD ECM.
