2004 Dodge Ram 1500 Idles High

Idles High

Dodge Engine jerks into gear

Q: 2004 Dodge Ram 1500 QC SLT 4.7L automatic engine with 165,000 miles. My idle continues to fluctuate. When I come to a quick stop the engine continues to idle high. While take off  truck moves slow for a few feet then jerks into gear. Also, in park or drive it sometimes jerks into gear.

A: It is most likely  throttle position sensor (TPS) issue. 

For 2004 Dodge Ram model truck 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.

Why Such Problem Occurs:

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.

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.

Monitoring TPS Signal:

The TPS signal can be monitored with a scan tool or lab scope. 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 will help.

Thanks.