U1821 BMW Fault Code

Description:

Brake Switch Circuit Input Malfunction Indicates PCM did not receive a brake pedal position (BPP) input. Open or short in BPP circuit Open or short in stoplamp circuits damaged PCM Malfunction in module(s) connected to BPP circuit.

(Rear Electronic Module [REM] Windstar and LS6/LS8 or Lighting Control Module (LCM) Continental and Town Car. Damaged brake switch Misadjusted brake switch Check for proper function of stoplamps.

U1821 Code Symptoms :

The scent may U1821 signal oil or coolant leaking from their normally closed-loop systems, or it may indicate dangerous exhaust gases invading your car's interior. Car and truck exhaust contains toxic gases such U1821, so if the inside of your car as if you were standing behind your car, get out and get it fixed.
Fight the urge to take a little nap first. So sleepy. That's the carbon monoxide talking, friends. At least open a window on your way to the shop.

Diagnosis And Repairing U1821

Parts or components should not be replaced with reference to only a U1821 DTC. The vehicle service manual should be consulted for more information on possible causes of the fault, along with required testing.

How to fix U1821 code ?

• Damaged ECM
• Faulty starter motor
• Intake Valve Timing Control Solenoid Valve harness is open or shorted
• Ignition coils harness is open or shorted

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.