Idle Goes Up And Down
Idle Problem On Dodge
Engine continues to idle high
Truck jerks into gear
Idle Gets Erratic
United States 2004 Dodge Ram 1500 Vehicle
Q: 2004 Dodge Ram 1500 QC SLT 4.7L automatic engine with 165,000 miles. Idle continues to fluctuate. Occasionally while coming to quick stop the engine continues to idle high. When I go to take off my truck moves slow for a few feet then jerks into gear. Also, when put it in park or drive it sometimes jerks into gear.
A: Throttle Position Sensor:
Most likely its a throttle position sensor (TPS) issue. The TPS is mounted on the left side of the throttle body and tells the engine and trans controllers how far the throttle is open.
Faulty TPS
When the sensor gets worn it will start to create small voltage spikes in it's signal and the engine controller things you are opening the throttle, so the idle can be erratic. If the voltage just stays high then so will the idle.
Trans Controller And TPS Signal:
The trans controller also receives the TPS signal and uses it for shifting control. If the idle fluctuation and the trans symptoms started at about the same time then the TPS is likely causing the shifting issues too.
TPS Signal Monitoring:
The TPS signal can be monitored with a scan tool or labscope. You can also try unplugging it while the idle is fluctuating, if it straightens up then replace the sensor. You can also tap on the sensor or wiggle the connector, if this has any effect on the engine then replace the sensor.
This details will help.
Thanks.
