Pontiac Bonneville U0121 Engine Error Code

When you check Pontiac Bonneville car engine light came on code U0121 the reason should be Engine Light ON (or Service Engine Soon Warning Light). However Pontiac manufacturer may have a different definition for the U0121 OBD-II Diagnostic Network (U) Trouble Code. So you should chech it on our car models.

To solve U0121 Pontiac Bonneville problem, you'll have to remove the muffler, crankcase and other components blocking the valve chamber. Then, remove the cylinder head bolts (label for easy re-installation) Adjust the jaws of the valve spring compressor until they touch the top and bottom of the valve chamber Push the tool in to compress the spring and tighten the jaws Remove the retainers and lift out the valves , compressors and springs

Pontiac Bonneville U0121 OBD-II Diagnostic Network (U) Trouble Code Description Pontiac Bonneville car U0121 OBD-II Trouble Code Modules connected to the high speed General Motor Local Area Network (GMLAN) serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and comm Reason For Pontiac Bonneville U0121 Code The reason of Pontiac Bonneville U0121 OBD-II Engine Error Code is U0121 Lost Communication With Electronic Brake Control Module.

If your vehicle failed a U0121 Pontiac Bonneville test and the 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 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 U0121 Pontiac Bonneville: Any conditions that might cause ignition misfire, an overly rich or lean fuel condition, or loss of compression.

Pontiac Bonneville U0121 Possible Solution :

Power Steering Pressure (PSP) Switch Signal Malfunction The PCM counts the number of times vehicle speed transitions from 0 to a calibratable speed. After a calibratable number of speed transitions the PCM expects that the PSP input should have changed. This DTC is set if the transition is not detected. Vehicle towed with engine running Power steering hydraulic concern was repaired but DTC was not erased PSP switch/shorting bar damaged SIG RTN circuit open PSP circuit open or shorted to SIGRTN PCM damaged Check, if possible, if vehicle was towed or power steering service was performed. Observe PSP V PID while checking wires for intermittents.

What does fault code U0121 mean for Pontiac Bonneville ? What does a diagnostic reading U0121 mean for Pontiac Bonneville ? How to fix OBD2 Code U0121 for Pontiac Bonneville ? What do we know about U0121 code for Pontiac Bonneville ?