SureTrack Community Fix: Don’t Talk To Me

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 age of diagnostics, communication between the vehicle and your scan tool is critical. When this doesn’t happen, it can be a frustrating search for the cause of that before you can get down to fixing the vehicle’s problems. SureTrack community member BekarAuto had a Ford Super Duty pickup in the shop that wouldn’t start and the scan tool couldn’t communicate with the computer. They posed the question to the community, and with the help of fellow community member jhirz and others, they were able to resolve the issue quickly.

The following Community Fix summarizes the interaction between members of the community that led to the solution.

Vehicle
1999 Ford Pickup F250 Super Duty 7.3L

Title
No start, no communication, replaced exhaust back pressure sensor.

Complaint
Customer complains that truck won’t start.

Diagnostic Steps Performed/Parts Replaced
Truck came in as a no start. Checked all the typical no start electrical items. Tried to scan for codes but found no communication issue with the computer. Have power at DLC. No blown fuses and all relays check out as good. Any suggestions before I start ripping into wiring harness looking for shorted wiring?

Best Answer from Community Member jhirz
Try unplugging the exhaust back pressure sensor on front of engine. It’s a three-wire sensor, wire colors of BR/W, P/LG, GY/R.

Cause
Exhaust back pressure sensor was bad, unplugged and truck started.

Correction
Replaced exhaust back pressure sensor, truck starts normally and scan tool can communicate with computer.


SureTrack® adds to the power of ProDemand® with an exclusive combination of real-world knowledge and powerful diagnostic tools, all wrapped in an interactive community of professional technicians. 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.