Inspect the preheating system when engine does not start at cold starting. If there is problem in the preheating system, engine hard starting occurs at cold starting or initial engine hesitation occurs after starting and exhaust fumes are discharged.
GCU (Glow plug Control Unit) is installed on the upper side of timing cover in the S-engine. Glow plug control current is optimized by GCU. And also GCU retrieves DTC after diagnosing each glow plug corresponding to engine condition.
IG KEY "OFF", ENGINE "OFF"
Connect a scantool to Data Link Connector (DLC).
Check DTC related to preheating system.
☞ U0106 CAN communication malfunction (ECM/PCM - Glow control module)
☞ P0670 Glow relay circuit malfunction
☞ P0671 Cylinder #1 - Glow plug circuit malfunction - open/short
☞ P0672 Cylinder #2 - Glow plug circuit malfunction - open/short
☞ P0673 Cylinder #3 - Glow plug circuit malfunction - open/short
☞ P0674 Cylinder #4 - Glow plug circuit malfunction - open/short
☞ P0675 Cylinder #5 - Glow plug circuit malfunction - open/short
☞ P0676 Cylinder #6 - Glow plug circuit malfunction - open/short
Symptom | Inspection procedure | |
Case1 | ● If DTC "U0106 CAN communication malfunction (ECM/PCM - Glow control module" is displayed. | ● IG "ON" power or CAN communication problem in the GCU circuit, ☞ Refer to DTC guide. |
Case2 | ● If DTC "P0670 Glow relay circuit malfunction" is displayed. | ● Main power or ground problem in the glow relay circuit, ☞ Refer to DTC guide. |
Case3 | ● If DTC "P0671~6 Cylinder # - Glow plug circuit malfunction - open/short" is displayed. | ● Glow plug poor connection, glow plug circuit or glow plug component problem. ☞ Refer to each DTC guide. |
