B1127 Chevrolet Suburban OBD Code

OBD/2 B1127 error code description and symptoms.

Low Speed Fuel Pump Primary Circuit Malfunction The PCM monitors the low speed fuel pump (LFP) primary circuit output from the PCM.
The test fails if: When the LFP circuit is commanded on (grounded), excessive current draw is detected on the LFP circuit; or when the LFP circuit is commanded off, voltage is not detected on the LFP circuit (the PCM expects to detect VPWR voltage coming through the low speed fuel pump relay coil to the LFP circuit). Open or shorted low fuel pump (LFP) circuit Open VPWR to low speed fuel pump relay Damaged low speed fuel pump relay Damaged PCM An open circuit or short to ground can only be detected with the low speed fuel pump.

As the engine heats up and combustion becomes easier and more complete, the PCM will command the idling control valve to increase the amount of air entering the engine to suit the changing conditions. However, when the load on the engine changes, say, when some electrical consumers or other systems are either turned on or off, the PCM adapts the signal voltage to the idle control valve to ensure that the idling speed remains stable, and at the RPM specified by the manufacturer.

B1127 Chevrolet Suburban Error Code Repair Process :

If your vehicle failed a B1127 test and the B1127 Check Engine Light is NOT on, chances are you have a problem with the OBDII system, a burned out MIL lamp, or a faulty catalytic converter. The converter is essentially an afterburner that cleans up the exhaust after it exits the engine. The OBDII system uses servo motor potentiometer defrost circuit short to battery a ownstream oxygen sensor to monitor the efficiency of the converter, and it should detect a drop in converter efficiency if the converter has been contaminated or is failing (ignition misfiring, leaky exhaust valves, and oil burning can all damage the converter). What you want to look servo motor potentiometer defrost circuit short to battery: Any conditions that might cause ignition misfire, an overly rich or lean fuel condition, or loss of compression. Use your OBD Express DIY to look at the oxygen sensor outputs, coolant temperature, airflow, calculated engine load, and inlet air temperature.

Common Causes of Chevrolet Suburban B1127 OBD2 Code

A common cause of code B1127 is the failure of Servo Motor Potentiometer Defrost Circuit Short To Battery, but there are several other possible causes as well, such as ;

EVAP canister or fuel tank leaks
Camshaft Position Sensor harness is open or shorted
Insufficient cylinders compression
Variable Camshaft Timing solenoid stuck open

B1127 is a kind of Body Trouble Code

Auto body problems aren't always easy to spot. Diagnosing auto body problems sometimes requires a little know-how. In this section you'll find articles dedicated to teaching you how to diagnose auto body problems.

Engine OBD 2 Codes website is a freeware resource center for engine trouble codes.

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B1127 Chevrolet Suburban OBD Code

B1127 Chevrolet Suburban Error Code Repair Process :

Common Causes of Chevrolet Suburban B1127 OBD2 Code

B1127 code for other Chevrolet cars