C2974 BMW Fault Code

Description:

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 C2974 as an indication of a hard fault.

C2974 Code Symptoms :

OBD C2974 code and tailpipe testing are two different approaches to identify vehicles in need of repair. The OBD system looks for broken or malfunctioning emissions control components and C2974, while tailpipe tests sample a vehicle's exhaust to see if it is above or below certain prescribed limits. Given the robust nature of today's emissions control components, it is entirely possible for an individual component to malfunction without leading to an immediate increase in emissions at the tailpipe.

In such cases, other components (like the catalyst) can temporarily compensate for the part that is broken however, these other components can only do double duty for so long before they, too, begin to malfunction. In addition, OBD also monitors for and other malfunctions in the fuel system problems that traditional tailpipe tests were not designed to identify. Most state and local areas also include a gas cap pressure test as part of an emission inspection.

Diagnosis And Repairing C2974

C2974 OBD 2 code on vehicles with electronically controlled automatic transmissions, the 3-4 shift solenoid is responsible for actuating the hydraulic circuits to activate clutches or bands that change gears inside the automatic transmission.

How to fix C2974 code ?

• Dirty Oil
• Failures of clutch motion/travel sensors.
• EVAP system hose leaking
• Ignition misfiring

Some systems require that the actuator has an adequate supply of brake fluid. Low brake fluid levels can mimic the symptoms of code C2974, so consult the manual to locate the brake fluid reservoir.

Bear in mind that a low fluid level can set code C2974 on some applications, so make sure that on fluid operated systems the fluid level is up to the mark before starting an electrical diagnosis.