FuelPump Relay Issues. Another potential cause for bad fuel pump symptoms is a faulty fuel pump relay. This relay controls the power supply to your Sierra's fuel pump, and a faulty relay may lead to: Intermittent power loss to the fuel pump; Inability to start your truck; Unpredictable pump operation, leading to stalling or rough running Ihave a 2003 mercury sable that I have replaced the fuel pump and relay on it will run for a couple of days and still goes back to acting like its running out of gas. Any ideas ? Posted by Scott speck on Oct 03, 2013. Want Answer 0. Clicking this will make more experts see the question and we will remind you when it gets answered. Whenthe ECM receives the crank signal, it activates the fuel pump relay by either controlling power to the control side of the relay, but more commonly, the ECM controls the relay by supplying aground. That wasn't so bad. Nice work! Sum Up. Checking the fuel pump fuse is a simple process that can be done with basic tools. Howto test the fuel pump on a 1995-2000 Ford Explorer. May apply to various years of Ford Rangers as well.Because of the large variations in power distribut Inthis video we go over a super common issue with the fuel pump driver module causing a no start due to corrosion.These are the Parts and Supplies I Recomme Swapinjection pump relay with horn relay and retest. DTC P0216 - Fuel Injection Pump Timing Failure . 1. If supply pump previously failed (within the last 2-3 months) it could cause advance Bad fuel Supply pump will normally cause this code. 2. Could also cause a DTC P0216. 3. Afterrun coolant pump: 1/6: Fuel pump relay left: -2/3: Secondary air pump relay 2: 2/4-2/5-2/6: Vacuum pump: 19: Fuel pump relay right: 20: Starter relay term.50: Learn more: How to check the fuses? How to replace a blown fuse? Why do car fuses blow? Types of automotive fuses. Search for: Search Link to Wells WebsiteDiagnosing a late model vehicle with a Fuel Pump Driver Module can be a real challenge when you are unsure how t 3QWIh.