Symptom Related Diagnostic Procedures

Troubleshooting for Communication Error with Scan Tool Using CAN

Perform this troubleshooting when it is not possible to communicate between scan tool and ECM / TCM.

NOTE:

- When performing this troubleshooting, be sure to have full understanding of Vehicle Damage Warnings Precaution of Troubleshooting for CAN
and observe it.
- It may be possible that CAN system has trouble because of fuse blown or low battery voltage. Before troubleshooting, check to make sure that fuse, battery voltage and generator status are normal.
- When disconnecting each control module connector in this troubleshooting, various DTCs will be detected. Be sure to clear DTCs in the following control modules after completing this troubleshooting.

- ECM
- BCM
- TCM (CVT model)
- Keyless start control module (keyless start model)
- 4WD control module (4WD model)
- ESP(R) control module (ESP(R) model)
- HVAC control module (Auto A/C model)
- P/S control module (EPS model)
- SDM (Advanced air bag model)

Wiring Diagram










Trouble area

- Scan tool
- Connector related to CAN line (included in DLC)
- CAN line
- Power or ground circuit of DLC
- Control module communicated by CAN

- ECM
- TCM (CVT model)
- ABS / ESP(R) control module
- BCM
- Combination meter
- Keyless start control module (keyless start model)
- 4WD control module (4WD model)
- ID controller (Canada model)
- SDM (Advanced air bag model)

- Sensor communicated by CAN

- Steering angle sensor (ESP(R) model)
- Yaw rate / G sensor assembly (ESP(R) model)

- Power or ground circuit of control module communicated by CAN
- Power or ground circuit of sensor communicated by CAN

Troubleshooting



1. Scan tool check

Disconnect scan tool from DLC with ignition switch turned OFF.
Check for proper connection to all terminals of scan tool connector.
If OK, connect scan tool to another vehicle of this type with ignition switch turned OFF.
Check communication between scan tool and BCM by checking BCM for DTC.

Is it possible to check BCM for DTC?
YES
Go to Step 2.
NO
Scan tool faulty. Refer to its operator's manual.

2. DLC power circuit check

Check for proper connection to all DLC (1) terminals with ignition switch turned OFF.
If OK, measure voltage between +B terminal (2) of DLC and vehicle body ground with ignition switch turned to ON position.






Is voltage 10 - 14 V?
YES
Go to Step 3.
NO
Repair power circuit.

3. DLC ground circuit check

Ignition switch turn to OFF position.
Check DLC (1) ground circuits as follows.
- Measure resistance between signal ground terminal (2) of DLC and vehicle body ground.
- Measure resistance between body ground terminal (3) of DLC and vehicle body ground.






Is resistance 1 ohms or less?
YES
Go to Step 4.
NO
Repair ground circuit(s).

4. DTC Check

Turn ignition switch to OFF position.
Connect scan tool to DLC.
Check DTC in the following control modules that communicate with scan tool by K-line.
- ABS / ESP(R) control module
- Keyless start control module
- 4WD control module

Is there any DTC other than CAN-DTC?
YES
Go to applicable troubleshooting of DTC other than CAN-DTC.
NO
Go to Step 5.

5. CAN line check between DLC and BCM

Turn ignition switch to OFF position.
Disconnect BCM connector from BCM.
Check for proper connection to all terminals of BCM connector.
If OK, check CAN lines between DLC and BCM connector for open, short to power circuit, short to ground circuit, short to other CAN line and high resistance.

Are CAN lines between DLC and BCM connector in good condition?
YES
Check CAN line.
NO
Repair CAN line.