Jaguar E Pace Diesel Glow Plug Module Failure Symptoms

Had similar issues on a 2016 Jaguar XF diesel. The persistent preheat light combined with engine light typically indicates problems with the glow plug system. A diagnostic test revealed faulty connections at the control unit, causing intermittent glow plug operation. The smoke during acceleration often happens when glow plugs fail to properly heat the combustion chamber, especially during cold start conditions. The repair involved replacing corroded wiring harness connectors and recalibrating the glow plug control module. This is generally not a major repair but requires proper diagnostic equipment to pinpoint the exact issue. The control unit needs testing to determine if its a simple connection problem or internal module failure. If left unaddressed, it can lead to starting problems and potential engine damage. Would recommend getting it checked soon, as faulty glow plugs can affect fuel economy and emissions. Make sure the shop has experience with Jaguar diesel engines and proper diagnostic tools. Ask them to check all glow plug resistance values and control module signals during testing.

Thanks for sharing your experience. Had nearly identical symptoms with my E Pace last winter, persistent preheat light and engine misfires during cold starts. The heating element problems eventually caused vehicle stalling. The fix included replacing two faulty glow plugs and the control module. The diesel engine runs perfectly now, no smoke or warning lights. Just curious, do you remember roughly what you paid for the repair? Also, have you noticed any other issues pop up since getting it fixed? Worth having it checked soon before winter sets in, as glow plug problems tend to get worse in cold weather.

Thanks for asking about the repair costs. Since having the control unit defective fixed at the shop, my Jaguar XF has been running flawlessly. The mechanic found a loose cable connection at the glow plug control unit which was causing the intermittent heating element failures. The total repair came to 95€, which covered diagnosing and fixing the faulty connection. Much cheaper than replacing the entire control unit, which I initially feared might be necessary. They also checked all glow plugs during the service, all tested within normal resistance ranges. No issues have surfaced in the 8 months since the repair. The engine starts perfectly even in cold conditions, and car maintenance has been routine only. The check engine light has stayed off, and the preheat system works exactly as designed now. You made the right call getting yours fixed before potential damage occurred. Regular glow plug system checks are essential for diesel engine longevity, especially before winter weather arrives.

Thanks for the responses and sharing repair costs. After putting it off for a few weeks, I finally took my E Pace to a diesel specialist shop last month. The diagnostic test confirmed what we suspected, faulty glow plug control module and two bad glow plugs. Total repair came to 680€ including parts and labor. More than I hoped but less than I feared. The mechanic showed me the corroded connections on the old module and explained how this caused the cold start issues and vehicle stalling. Been about 3 weeks since the repair. Engine fires up instantly now, even on cold mornings. No more smoke or warning lights. Car maintenance schedule is back to normal intervals. Definitely worth fixing before winter, the car runs better than it has in months. Lesson learned about not waiting too long when diesel engine problems first appear. Better to catch these issues early before they cause more expensive damage.