Erratic Throttle: SureTrack Real Fix

June 22, 2021 by Nick Taylor

Real Fixes from Mitchell 1’s SureTrack® expert information resource are documented issues from actual shop repair orders and community discussions. Read on to see how SureTrack can help you correct issues that are not easily diagnosed using OEM information alone. SureTrack is available at no additional cost in our ProDemand product.

In the “good ole days”, the gas pedal was physically connected to the carburetor or throttle body. Now most vehicles connect the throttle pedal through the wiring and throttle control issues can require a lot of testing. Follow this Real Fix to see how codes P2110 and P2118 on a 2016 Jeep Patriot were diagnosed to find the components causing the issue.

Vehicle
2016 Jeep Patriot Sport 2.0L

Title
P2110, P2118, Replaced Throttle Body, Throttle Body Gasket

Complaint
The customer states the check engine light is on.

Cause
Connected a scan tool and found codes: P2110 – Electronic Throttle Control – Forced Limited RPM and P2118 – Electronic Throttle Control Motor Current Performance. With the engine running used the scan tool to monitor live data and found the throttle position 1 (TP1) and the throttle position 2 (TP2) specified TP1 0.5 to 4.5 Volt and TP2 4.5 to 0.5 Volt sensor signal parameters were erratic as the accelerator pedal was depressed. Commanded a throttle sweep with the scan tool, monitored the throttle position sensor signal parameters using the lab scope and found the throttle position sensor signal parameters produced an erratic signal and waveform pattern. Performed a visual inspection of the throttle body connector, terminals and wiring harness, but found no obvious faults. Key on, engine off, used the multi-meter back-probed the TPS connector TPS 1 and TPS 2 on the throttle body, voltage should be below 0.5 Volt with the throttle closed. Open throttle to wide open throttle (WOT) a clean voltage sweep should be seen to 4.5 Volts with no dropouts or glitches. At all throttle openings, the sum of the voltage outputs from TPS 1 and TPS 2 should equal 5 Volts. Key on, engine off, used the multi-meter to probe the connector for the throttle actuator control (TAC) 1 and 2. Voltage should be 12 Volts and polarity should reverse when throttle is snapped. With the intake tube removed, commanded a throttle sweep with the scan tool and found the throttle valve operation was erratic and intermittently sticking. The TPS 1, TPS 2 and TAC motor are integrated into the throttle body and are replaced as an entire unit. Removed the throttle body for inspection and found the throttle body gasket was damaged. The results of these tests verified the throttle body and the throttle body gasket were faulty.

Correction
Replaced the throttle body and throttle body gasket, cleared codes, performed a road test and verified the vehicle operated properly. The check engine light did not illuminate and no fault codes returned.

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About the Author Nick Taylor  

Nick Taylor is the SureTrack Community Administrator and a Senior Applications Specialist at Mitchell 1 with over 25 years of experience with electronic repair data systems. Nick previously worked in the automotive dismantling and engine rebuilding industries.