P148A BMW Fault Code

Description:

The Throttle Position sensor signals the Engine Control Module as to the current position of the engine throttle valve.
The current throttle valve opening is based on the driver's input from the gas pedal.

The ECM uses the information from this sensor to help calculate fuel delivery and spark timing.

P148A 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 P148A 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 P148A

Parts or components should not be replaced with reference to only a P148A DTC. The vehicle service manual should be consulted for more information on possible causes of the fault, along with required testing.

How to fix P148A code ?

• Faulty Air Flow Meter
• Faulty Crankshaft Position Sensor (POS)
• Improper ignition timing
• Oil flow restriction in the oil passages or the variable camshaft timing (VCT) valve body

On some transmissions, such as automated manual transmissions or automatic transmissions with manual mode, the GSP switch lets the TCM know whether or not the driver has selected automatic or manual function.

On manual transmissions, the GSP switch informs the TCM which gear the driver is selecting, and may function as a neutral safety switch, depending on system design. The TCM also uses the gate select position switch to monitor transmission operation. For example, if the driver selects manual mode and selects 3rd gear on an automatic transmission, the TCM may monitor speed sensors to detect clutch and brake slippage.