Diagnostic trouble code (DTC) information

Condition 

If engine speed (RPM) is above 3500 rpm and the engine is operating at a high load, the control signal to the turbocharger (TC) control valve is at maximum and the boost pressure (from boost pressure sensor) is lower than a designated value (approximately 20 kPa (2.90 psi) under normal boost pressure - signal too low).

If the air mass (from mass air flow (MAF) sensor) is higher than a desired value (signal too high) it is interpreted as a fault and diagnostic trouble code (DTC) ECM-6806 is stored.

Substitute Value 

reduced boost pressure

Possible Source 

Signal too high: 

• air leakage after turbocharger (TC)

Signal too low: 

• hoses between turbocharger (TC) and turbocharger (TC) control valve respectively turbocharger (TC) control valve and pressure servo are loose or are blocked/damaged
• faulty turbocharger (TC) control valve
• faulty boost pressure control (BPC) valve pressure servo
• sticking boost pressure control (BPC) valve

Fault symptom[s] 

• none