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P0229 is a diagnostic trouble code (DTC) for "Throttle/Pedal Position Sensor/Switch C Circuit Intermittent". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.
Throttle/Pedal Position Sensor/Switch C Circuit Intermittent
P0229 is an OBD-II generic code indicating the throttle/pedal position sensor/switch C circuit has an intermittent input problem causing the sensor input to the engine control module (ECM) to be intermittent and within the the expected voltage input when compared to the throttle position sensor A.
The engine control module (ECM) detects erratic input voltage from the sensor circuit to the ECM, but still within the specified range for the sensor when it is working.
Corrosion in the connections to the sensor can cause the erratic voltages from the sensor.
Loose connections to the sensor can cause the voltage to be erratic.
The Check Engine and Electronic Throttle Control (ETC) Light will be illuminated
The ECM will go into failure limp home mode and drive complaints may vary depending on manufacturer programming
The throttle is shut completely during stops to prevent excessive RPM’s when stopping the vehicle
The throttle may be set to a fixed position during acceleration to limit throttle opening
Uneven idle or jerking during braking due to the closed throttle position
Very poor throttle response during acceleration or no response at all limiting acceleration
The vehicle speed will be limited to 32 mph or less
The symptoms may go away if the vehicle is restarted, but the Check Engine Light will remain until repairs are done or codes are erased
Scans codes and documents the freeze frame data in order to verify the problem
Clears the engine and ETC codes to verify concern comes back
Does a visual check of the wiring and connections to the throttle body sensors for loose or corroded connections
Checks scan data to see if sensor signal voltage is erratic while doing a wiggle test of the connector and wiring to find cause of the intermittent connection problem
Disconnects and checks the sensor resistance to see if the sensor is having an internal intermittent circuit failure by exercising the throttle plates and lightly tapping the sensor to simulate road shock
Follow these simple guidelines to prevent misdiagnosis:
Simulate road shock to sensor while monitoring data to isolate failure in the sensor or in the connection and wiring
Look for any problems with burnt or cut wiring to the sensor or corrosion in the connections that can cause erratic voltage output
Any problems with the throttle sensor causes the limp mode to be activated.
The engine will go into limp home mode and systems will be limited depending on manufacturer.
The vehicle speed will be limited to less than 35 mph.
The engine will lack acceleration or have limited acceleration.
The engine idle will be low and erratic when coming to a stop.
The vehicle fails emission testing.
Repairing or replacing wiring or connections to the sensor
Replacing a defective throttle body control assembly for internal faults
Replacing or reprogramming the ECM if directed by the pinpoint tests after all other tests pass and no other faults with the sensor or wiring is found
Code P0229 is caused by erratic or intermittent signals from the sensor to the ECM. These signals are still within the specified range of the sensor when the signal is being received by the ECM.
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