B1602
DTC B1602 CAN BUS PHYSICAL ERROR, BUS FAILUREComponent Location:
GENERAL DESCRIPTION
To make system be more efficient, Body Control Module (hereinafter referred to BCM) applies CAN (Controller Area Network) communication system. CAN is a kind of communication system which can make related component share system information with just two line instead of complex individual signal line. It consists of related component and CAN BUS which consists of CAN high line and CAN low line. Each component can send and receive information by binary signal via CAN BUS. The related components for BCM are IPM, ADM, DDM, FAM, RAM, IMS and cluster module.
DTC DESCRIPTION
The ECM sets DTC B1602 if there's any short circuit in CAN high line and CAN low line including short to each other.
DTC Detecting Condition:
MONITOR DTC STATUS
1. Connect scantool to Data Link Connector(DLC).
2. Ignition "ON" & engine "OFF".
3. Select "Diagnostic Trouble Codes(DTCs)" mode and monitor "DTC Status" parameter.
4. Is the DTC B1602 present?
YES - Go to "Inspection & Repair" procedure.
NO - Fault is intermittent caused by poor contact in the sensor's and/or ECM's connector or was repaired and ECM memory was not cleared. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.
TERMINAL AND CONNECTOR INSPECTION
1. 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.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?
YES - Repair as necessary and go to "Verification Vehicle Repair" procedure.
NO - Go to "W/Harness Inspection" procedure.Testing and Inspection
SIGNAL CIRCUIT INSPECTION
1. Check CAN high communication circuit
1. Ignition "ON" and Engine "OFF".
2. Connect scantool and select VEHICLE SCOPEMETER function.
3. Measure waveform between terminal "BCM-IF-30" of IPM and chassis ground.
Specification : CAN communication waveform is displayed
4. Is the measured waveform within specifications?
- The existance of CAN communication waveform itself shows there's no trouble in CAN communication circuit. If there's any short in harness, no signal is detected.
YES - Go to "Check CAN low communication circuit" procedure.
NO - Check for short circuit in signal harness. Repair as necessary and go to "Verification Vehicle Repair" procedure.
2. Check CAN low communication circuit
1. Ignition "ON" and Engine "OFF".
2. Connect scantool and select VEHICLE SCOPEMETER function.
3. Measure waveform between terminal "BCM-IF-39" of BCM ECU and chassis ground.
Specification : CAN communication waveform is displayed
4. Is the measured waveform within specifications?
- The existance of CAN communication waveform itself shows there's no trouble in CAN communication circuit. If there's any short in harness, no signal is detected
YES - Go to "Component Inspection" procedure.
NO - Check for short circuit in signal harness. Repair as necessary and go to "Verification Vehicle Repair" procedure.
COMPONENT INSPECTION
1. Check Related component
1. Connect scantool to Data Link Connector (DLC).
2. Ignition "ON" & engine "OFF".
3. Select "Diagnostic Trouble Codes (DTCs)" mode and monitor "DTC Status" parameter.
4. Check if the DTC is erased while disconnecting related component one after another.
- Related component :IPM, ADM, DDM, FAM, RAM, IMS, Cluster module.
5. Is the DTC erased?
YES - Substitute with a known-good pertinent component and check for proper operation. If the problem is corrected, replace pertinent component and then go to "Verification of Vehicle Repair" procedure.
NO - Check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.
VERIFICATION OF VEHICLE REPAIR
After a repair, it is essential to verify that the fault has been corrected.
1. Connect scantool and select "Diagnostic Trouble Codes (DTCs)" mode and then clear DTC.
2. Operate the vehicle and monitor the DTC on the scantool.
3. Are any DTCs present?
YES - Go to the applicable troubleshooting procedure.
NO - System is performing to specification at this time.