U3457 BMW Fault Code
Check U3457 OBD Fault Code ReasonThe Camshaft Position sensor will signal the Engine Control Module when the #1 cylinder is ready for the spark plug to fire (top-dead-center on compression stroke).
The ECM uses the information from this sensor to help calculate fuel delivery and spark timing.
U3457 Code Symptoms :
The rule of U3457 code when it comes to emissions-related vehicle repair is that any modification that changes the vehicle from a certified configuration to a non-certified configuration is considered tampering: this applies to both vehicle owners and repair facilities and is, therefore, a Federal offense. Replacing a catalyst with a straight pipe is one traditional example of U3457.
Likewise, overriding the OBD system through the use of high-tech defeat devices or non-certified computer chips, for example, would also be considered tampering. The OBD system may, however, be repaired back to its original certified configuration with certified performance chips or appropriate aftermarket parts.
Diagnosis And Repairing U3457
Parts or components should not be replaced with reference to only a U3457 DTC. The vehicle service manual should be consulted for more information on possible causes of the fault, along with required testing.
How to fix U3457 code ?
- Exhaust gas leaks
- Faulty starter motor
- Faulty spark plug (s)
- Faulty Air Flow Meter
A good starting point in your diagnosis is checking all system fuses and fusible links. This can be done using the BMW DVOM on the voltage setting. You will want to test the fuses with circuits loaded.
Some fuses will appear normal until a load is placed on their respective circuit; at which point they will fail. This has been the cause of many 'phantom malfunctions'. Consult your vehicle information source for fuse and fusible link locations. If all fuses are in working order, you may want to check TCM relay operation by swapping identical relays. Usually the horn relay, starter relay, fuel pump relay, air conditioning clutch relay, and controller relays are similar enough in design to swap for diagnostic purposes.
