What happened to my 1996 X300 back in January this year is worth sharing as at the time the fix for the intermittent fault had not been recognised worldwide.
The Symptom:
Jan 9 (89,500 km) I am making a right hand turn into the driveway of my home when the engine cuts out. I wait a few moments and restart the car. I am able to drive it into the garage when I notice the Auto Transmission Failure warning light was on. I phoned my service technician Michael Gill-Bailey at the Jag Workshop at Sandgate and arranged to have the car checked the next day. Before leaving for Sandgate my wife Lois sprinkled holy water on the car and during the drive via the gateway I prayed that the engine would get me to Michael’s without incident, I made it safely. Michael explained that it could be a component starting to fail or a fault in the wiring loom, the diagnostic time for an intermittent fault can be huge. To keep costs down and my car on the road he suggested trying a part at a time.
The Problem:
Michael’s initial diagnosis was a problem with the Engine Control Module which he replaced and asked me to check out over the next ten days. Leaving Sandgate on the freeway I lost throttle control at 90 kph, I was able to flick the throttle pedal and regain power. No warning light came on. I continued home with no problem, staying in the nearside lane in case I needed to pull over suddenly. Over the next ten days I had eight incidents of engine cut out or loss of throttle, fortunately I was always able to restart the car and get home. I became very alert, anticipating safe places to get out of the traffic.
Jan 22 – 24. Back to Michael’s and the engine cuts out on the Gateway at the Toombul turnoff, I manage to get out of the traffic flow. My anxiety level is increasing. I continue to Sandgate with the warning light on. Michael runs the diagnostic check and finds Fault Codes P0727 and P1775. He replaces the Transmission Control Module, checks engine speed signal from ECM to TCM and fits another Crankshaft Sensor and I test the car for another ten days. Unfortunately the engine cut outs continue and I have a growing concern as to my safety when driving the car.
The Remedy:
Feb 6 – 9. Car returned to Michael’s for replacement air meter, spark plugs, throttle body and check out of the wiring loom. He is looking for a continuity problem for the engine speed signal dropping out when the wiring was hot. Success, he finds a problem with the P1 Harness Plug (see white plastic plug to the left of the windscreen washer bottle neck in photo). The car runs great again!
It turns out that the good work Michael did in trouble shooting this problem has helped others worldwide. Thanks again Michael (ph: 3269 6363) for your persistence and determination in finding a fix for the problem, my Cat is purring happily again.
