C1978 Volkswagen Kombi OBD Code

OBD/2 C1978 error code description and symptoms.

EGR Flow Insufficient Detected The EGR system is monitored during steady state driving conditions while the EGR is commanded on.
The test fails when the signal from the DPF EGR sensor indicates that EGR flow is less than the desired minimum. Vacuum supply EGR valve stuck closed EGR valve leaks vacuum EGR flow path restricted EGRVR circuit shorted to PWR VREF open to D.P.F. EGR sensor D.P.F. EGR sensor downstream hose off or plugged EGRVR circuit open to PCM VPWR open to EGRVR solenoid D.P.F. EGR sensor hoses both off D.P.F. EGR sensor hoses reversed Damaged EGR orifice tube Damaged EGRVR solenoid Damaged PCM Perform KOER self-test and look for DTC C1978 as an indication of a hard fault.

In most cases, the TCM is integrated into a single housing with the PCM. Nevertheless, the section of the module which controls (automatic) transmission function may be powered up separately. In any case, the TCM is typically powered using switched (only present with the ignition switch in the ON, start, or run position) voltage. This circuit is normally equipped with a fuse, fusible link, and/or a relay. Frequently, the PCM and TCM are powered using the same relay albeit by separate circuits. Access to a reliable vehicle information source will yield necessary details of the TCM power circuit for the specific vehicle in question.

C1978 Volkswagen Kombi Error Code Repair Process :

If your cooling fan circuit over current check engine light is illuminated, it's best to take it in for diagnostic testing, which can feel like a hassle. Because while the lights vary in appearance from vehicle to vehicle, all have the same basic meaning: There's a problem with the car's emissions system. The on-board diagnostics system C1978 and engine control unit are in charge of monitoring a bunch of different cooling fan circuit over current, and if they get a reading that's a little out of whack, up pops the check engine light.

Common Causes of Volkswagen Kombi C1978 OBD2 Code

A common cause of code C1978 is the failure of Cooling Fan Circuit Over Current, but there are several other possible causes as well, such as ;

Air fuel ratio (A/F) Sensor 1 Bank 1 circuit poor electrical connection
Faulty front heated oxygen sensor
Intake Valve Timing Control Solenoid Valve harness is open or shorted
Damaged camshaft position (CMP) sensor

C1978 is a kind of Chassis Trouble Code

Diagnosing chassis noises can be one of the most frustrating problems technicians face. Fortunately, manufacturers have engineered noise, vibration and harshness (NVH) diagnostic techniques and equipment to find the source of the noise.

C1978 Volkswagen Kombi OBD Code

C1978 Volkswagen Kombi Error Code Repair Process :

Common Causes of Volkswagen Kombi C1978 OBD2 Code

C1978 code for other Volkswagen cars