robin_smith5
F Pace No-Start: Terminal 15 Ignition System Alert
Summary of the thread
The F Pace is experiencing a no-start issue with a Terminal 15 ignition system alert, characterized by a complete lack of power when turning the key and silence from the starter solenoid. The problem may stem from a deteriorating relay switch or wiring harness, as similar symptoms were resolved by replacing a damaged relay switch assembly and wiring near the fuse box. A voltage drop test is recommended to identify any circuit breaks, and careful inspection of the wiring around the relay assembly is advised, especially since the issue developed gradually and worsened after recent maintenance.
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4 comment(s)
robin_smith5 (community.author)
Last service was 4 weeks ago at 141000 KM. Thanks for the detailed response. The power supply issues started gradually over the past weeks. The car would occasionally hesitate before starting, especially on cold mornings. At first I thought it was just battery terminal corrosion, but cleaning them made no difference. Our situations sound similar, especially the complete silence from the starter solenoid. The wiring harness suggestion makes sense given how the problem developed. Did you notice any visual damage to the wires when you found the faulty relay? The circuit break in my case seems to be preventing any power from reaching the starter. I will get the voltage drop test done as you suggested before proceeding with repairs. The complete lack of electrical response when turning the key definitely points to a power distribution issue rather than just a starter motor problem.
jana_phoenix53
Based on my experience with the F Type issue I mentioned, what you're describing sounds nearly identical to my situation. The gradual onset of starting problems is a classic sign of a deteriorating relay switch or wiring harness. In my case, the visual damage wasnt obvious at first. The wiring insulation looked intact, but the voltage drop test revealed the circuit break. The workshop found corroded wires inside the protective sleeve near where the relay switch connects to the main harness. Since your symptoms developed over time like mine did, and theres zero response from the starter solenoid, Id strongly suspect the same failure point. The complete silence when turning the key typically means the ignition power isnt reaching the starter circuit at all. The timing after your service is interesting, sometimes moving wiring harnesses during maintenance can aggravate an already weakened connection. The fact that cleaning the battery terminals didnt help also supports this being a wiring or relay issue rather than a simple connection problem. Get the voltage drop test done first, but be prepared that you might need the relay switch assembly and associated wiring replaced. The good news is that once fixed, the problem shouldnt return as long as quality parts are used.
robin_smith5 (community.author)
Thanks for the helpful information about your F Type experience. Its interesting how these power supply issues can start so subtly and worsen over time. My F Pace is a 2019 3.0L diesel. No warning lights appeared before the complete failure, but looking back there were signs. About 3 weeks ago I noticed the interior lights would sometimes flicker when first turning the key. The fuel pump sound was getting less noticeable too before it stopped completely. Your description of the wiring harness damage near the relay switch sounds exactly like what might be happening here. I am going to have the voltage drop test done tomorrow to check for any circuit break issues. The workshop suspects the complete lack of power when turning the key points to a break between the fuse box and starter circuit. Given how the problem developed gradually like yours did, I will ask them to carefully inspect all the wiring around the relay assembly. The fact that moving wires during maintenance might have sped up an existing issue makes a lot of sense, the timing fits with when things got noticeably worse. Will update once I know more after the tests. Hoping its just the wiring harness or relay switch and not something more extensive in the electrical system.
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JAGUAR
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FPACE
jana_phoenix53
I had a similar starting issue with my F Type from around the same period. With some experience working on Jaguars, I can share what worked in my case. The symptoms matched exactly, car won't start, no response from the starter solenoid, despite having good battery terminal connections. After a voltage drop test, my workshop found a damaged relay switch wiring harness near the fuse box that was causing an intermittent circuit break. The fix involved replacing the damaged wiring section and installing a new relay switch assembly. Total cost was 95€ for parts and labor. Since then, no more starting issues. Before suggesting specific fixes for your case, could you share: Build year of your F Pace, Engine size and type, Whether you notice any electrical issues before the complete failure, If any warning lights appeared on the dash, Whether you hear the fuel pump prime when turning key to ON These details would help narrow down if your issue matches what I experienced or if it might be something different in the ignition circuit.