C1543 BMW Fault Code

Description:

Engine Coolant Temperature (ECT) Circuit High Input Indicates the sensor signal is greater than Self-Test maximum. The ECT sensor maximum is 4.6 volts or -50 C (-58 F). Note on some vehicles that are not equipped with an ECT sensor, CHT can be used and can set this DTC. Open circuit in harness Sensor signal short to power Damaged PCM Improper harness connection Damaged sensor ECT V PID reading greater than 4.6 volts with key ON and engine OFF or during any engine operating mode indicates a hard fault.

C1543 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 C1543 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 C1543

C1543 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 C1543 code ?

• Camshaft advance mechanism binding (VCT unit)
• Faulty select solenoid
• Air fuel ratio (A/F) Sensor 1 Bank 1 circuit poor electrical connection
• Faulty Mass Air Flow (MAF) sensor

Circuit High Input codes like C1543 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.