The PCM regularly checks the park/neutral position switch and compares its signal to pre-programmed values in its memory. If the computer doesn’t get the right response, it will set a code P0850. Note: The definition of code P0850 can differ according to the vehicle manufacturer. Check the appropriate repair manual or repair database for the In fact, symptoms of a faulty speed sensor may also result symptoms of other common components such as a defective coil pack or bad throttle position sensor. However, here is a list of the most common symptoms associated with a bad engine speed sensor: Transmission revs higher before it changes gears. The car's transmission engages into The throttle position sensor (TPS) monitors the position of the throttle body butterfly valve. This allows your vehicle's computer to regulate the air intake and manage the fuel and air mixture. Throttle position sensors are often mounted to the throttle body itself, and may have a lever arm that moves as the throttle changes position. It was a missing, yes missing, elbow on the vacuum line from the PCV to the manifold way in the back behind the throttle body. 2004 Jeep Grand Cherokee WJ Overland, 4.7V8 HO 125K miles. Symptoms: sudden onset of high idle (NOT rough idle) on startup (1000 rpm) and at warmup idle jumps to 1200-1500 depending on A/C on/off, drive or park/neutral. 400 RPM, but less than 1500 RPM, and Throttle Position Sensor (TPS) voltage must be less than one volt. Possible causes are: short to ground in MAP sensor signal circuit (Dark Green/Red wire on XJ and YJ bodies or Red/White wire on ZJ body), MAP sensor shorted internally or loss of MAP sensor 5-volt supply circuit (Violet/White wire). Go to Changed the pcm, and no more problems. If it is the pcm, you can get one as a plug n play (already coded) from 2005 Jeep Grand Cherokee PCM ECM ECU Engine Computer for less than $200. Another thing to check is the black connector from the accelerator cable / pedal to the system. Solution: The throttle control system controls the air-fuel mixture that your engine burns. If it starts sending the wrong signals, it can inject way more fuel than is needed. The associated trouble code should identify a problem with the throttle controller, which can then be repaired. What the P2172 code means. The P2172 code means that a large amount of airflow was suddenly inducted into the throttle actuator control system. The electronic control unit (ECU) detects this large amount of air and the P2172 diagnostic trouble code (DTC) is set. When the code is set, the Check Engine Light will be illuminated on the dashboard. lBFRP.

jeep grand cherokee throttle position sensor symptoms