Button Engine Start System

General Description

This is DTC which is related with communication error between PDM and other units.
(** Control Units : BCM (Body Control Module), PDM(Power Distribution Module), SMK(Smart Key) ECU.
* CAN (Controller Area Network) : CAN is serial bus communication type which links not only communication system but also control units each other.
*2 LIN (Local Interconnect Network) : LIN is serial communication type which is used in electrical control system. (This is less expensive.)






DTC Description






Communication is normal but DTC set if PDM detects 7 error status as follows.
1. Short to battery in CAN High circuit
2. Short to ground in CAN High circuit
3. Short to battery in CAN Low circuit
4. Short to ground in CAN Low circuit
5. Short between CAN High and Low circuit
6. Open or Poor connection in CAN Low circuit
7. Open or Poor connection in CAN High circuit

DTC Detecting Condition






Diagnostic Circuit Diagram






Signal Waveform & Data










Fig.1) Signal waveform of CAN Low and HIGH
Fig.2) CAN BUS VOLTAGE LEVEL (LOW SPEED CAN)

Monitor Scantool Data

Check DTC
1. Connect GDS.
2. IG "ON" and engine "OFF".
3. Select "DTC Analysis" mode.
4. After erase DTC, keep the vehicle condition within "the enable conditions"







5. Is the same DTC occurred again?






Terminal & Connector Inspection

1. Many malfunctions in the electrical system are caused by poor harness(es) 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?






Signal Circuit Inspection

Check CAN high circuit
1. IG "ON" & ENG "OFF".
2. Connect GDS and select Scope meter function.
3. Measure signal waveform of PDM CAN High line.

Specification :Refer to signal waveform and data

4. Is the measured signal waveform of CAN high circuit normal ?





Check CAN Low circuit
1. IG "ON" & ENG "OFF"
2. Connect GDS and select Scope meter function.
3. Measure signal waveform of PDM CAN Low line.

Specification :Refer to signal waveform and data

4. Is the measured signal waveform of CAN low circuit normal ?






Component Inspection

Check internal errors of CAN communication units
1. Connect GDS.
2. IG "ON" and engine "OFF".
3. Select "DTC Analysis" mode.
4. Disconnect CAN communication units one by one and monitor DTC to find the cause.
*CAN communication units : BCM(Body Control Module), PDM(Power Distribution Module), CLU(Cluster), SMK(Smart Key) ECU.
5. Is the code erased?






Verification of Vehicle Repair

After a repair, it is essential to verify that the fault has been corrected.
1. Connect scan tool and select "DTC Analysis" mode.
2. Clear the DTCs and Operate the vehicle within DTC Enable conditions in General information.
3. Is any DTC outputted again?