B1738 BMW Fault Code
Check B1738 OBD Fault Code ReasonFuel Rail Pressure Sensor in Range But Low The comprehensive component monitor (CCM) monitors the FRP pressure for acceptable fuel pressure. The test fails when the fuel pressure falls below a calibrated value.
Low fuel pressure Damaged BMW FRP sensor Excessive resistance in circuit Low or no fuel A FRP PID value below 551 kpa (80 psi) indicates a failure Low or no fuel A FRP PID value greater than 896 kpa (130 psi) indicates a failure.
B1738 Code Symptoms :
While fuel economy was increased, acceleration was seriously compromised, and the loss of engine vacuum led to a dangerous loss of braking assist when the B1738 code system was in four-cylinder mode. In addition to these issues, while the company proposed a hydraulically controlled system that could be switched from within the car, the version they implemented had to be manually changed in the engine compartment using hand tools.
Diagnosis And Repairing B1738
B1738 the main thing to check is to verify the operation of the VCT solenoid. You're looking for a sticking or stuck VCt solenoid valve caused by contamination. Refer to vehicle specific repair manual to perform component tests for the VCT unit.
How to fix B1738 code ?
- 1Camshaft Position Sensor circuit poor electrical connection
- Camshaft Position Sensor harness is open or shorted
- Incorrect Positive Crankcase Ventilation (PCV) hose connection
- Air fuel ratio (A/F) Sensor 1 Bank 1 circuit poor electrical connection
Circuit High Input codes like B1738 are mostly caused by defective alternators that develop excessive voltages, although there may be other causes as well, such as short circuits that 'leak' current into a particular system from other, unrelated systems that work on higher voltages. Note that in the case of short circuits that leak power into a control circuit, there is likely to be other, seemingly unrelated trouble codes present along with the code(s) being investigated. Diagnosing a 'high input' code will always involve a thorough testing of the charging system as a first step, followed by measures to isolate the system from all other possible sources of power during resistance, continuity, and reference voltage tests.