SureTrack Real Fix: Put the Pedal Down

Real Fixes from ShopKey’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 currently available free with the purchase of a current Snap-on® diagnostic software version or in our ShopKey Pro product.


Uh oh! You got a code for a ECU malfunction, that could get expensive. But it’s not always that simple. Follow this Real Fix to see how this code was caused by another component on this GMC Envoy.

Vehicle
2004 GMC Envoy 4.2L

Title
P1680, Replaced Accelerator Pedal Position Sensor

Complaint
The customer states the check engine light is on.

Cause
Connected a scan tool and found code P1680 – ECU Malfunction. With the key on, engine off, used the scan tool to monitor live data and found the accelerator pedal position sensor 2 signal parameter was not present. Disconnected the accelerator pedal position sensor connector, visually inspected the connector and terminals and found no obvious signs of damage. With the accelerator pedal in the rest position, used a multi-meter to measure the resistance of the accelerator pedal position sensor 2 between the 5 volt reference circuit and the accelerator pedal sensor 2 signal circuit and found the measured resistance was above the maximum specification of 450 Ohms. These test results verified the accelerator pedal position sensor was faulty.

Correction
Replaced the accelerator pedal position sensor, cleared codes, performed a road test and verified the vehicle operated properly. The check engine light did not illuminate and no fault codes returned.


SureTrack® adds to the power of ShopKey Pro with an exclusive combination of expert knowledge and detailed parts replacement records, all wrapped in an interactive community. Designed to help automotive shops increase accuracy and efficiency from diagnosis to completed repair, the industry’s most comprehensive repair information resource is just a few clicks away.

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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.