Cranks... no start. Only a P0125 DTC. No MIL. No other powertrain DTCs.

Checked ECT Sensor resistance... 35.1 ohms on 200k scale, at 20° Celsius.

Heated ECT Sensor base with hair dryer to 60° Celsius. Immediately went to turn key. Brief start, like 2 seconds.

Heated ECT Sensor base with heat gun to around 133° Celsius. Immediately went to turn key. Cranked and started, ran longer, but sputtered out. Repeated. Same result.

Got new ECT Sensor. Pre-checked resistance. 33.3 ohms on 200k scale at 20° Celsius.

Changed ECT Sensor. Just cranks, no start. Won't even start and sputter out after heating the new ECT Sensor.

Checked ECT Sensor ground circuit (ok); ground circuit for short to battery positive (ok); circuit for short to battery positive (ok).

Didn't check signal wire for open circuit, or short to ground... have to access ECM connector.

Why did heating the old sensor get the car to briefly turn over, but nothing with new sensor?

The 33.3 ohms at 20° Celsius on new sensor seems wrong; nearly same as old sensor. FSM says 2437 to 2464 ohms at 20° Celsius. Defective new sensor? Other issues?

 

What is the fuel pressure whilst the engine is cranking?

 

I'd like to check that. Can't find my schrader valve adapter for my gauge, but I can get live data on the scanner.

 

You can use the Torque app with a Bluetooth interface to access the PCM and read the fuel pressure. Should be around 300 kPa when cranking the engine.

 

I got it started. After several weeks of it corking up my driveway, I was able to move it out of the way.

I'm going to let it set overnight and see if it starts ok tomorrow. If it does, I'll let you know what the issue was.

 

It started right up today. Here's what I think the issue was...

I've had ABS/CATS issue for 4 months. Haven't got to check it because of a miserable winter. When I first got the issue, speedo & odo quit. I also remembered my fuel gauge reading dropped.

I never drive the car in winter. I start it, idle it, move it around driveway. Did that regularly til it wouldn't start 9 weeks ago.

Started thinking the other night about first thing to check on car that cranks but won't start. Does it have gas? Then, I thought about how the gauge read wrong after ABS/CATS issue began. Fuel gauge showed 1/4 all winter.

Yesterday... Scanned... scanner showed Fuel Level Signal 0%. Tried to hear fuel sloshing in tank by rocking car. Sounded weak. So, I put a 5 gallon can of gas in.

Fuel Level Signal went to 72%.

Scanner showed non-cranking Fuel Rail Pressure 2 psi.

Tried starting. Only cranked. FRP while cranking 1.3 to 2.6 psi.

Used heat gun to heat base of ECT Sensor. Cranked it. Sputtered. Sputtered again. Then, started.

FRP showed 38.7 to 41.3 psi, at idle.

Engine temp steady at 194°. Cluster gauge in middle.

Fuel gauge now shows 5/8ths. So, it magically took 5 gals and turned it into about 6.9 gals. Fuel gauge has become quirky since ABS/CATS Fault. I suspect tank had been near empty.

First time I ever neglected to check if there was gas in tank, but I blame the gauge.

Another goof... the can of gas I put in... 87 octane.

Today, FRP was 37.0 psi after sitting overnight. Fuel Level Signal was 0% again. ??? ECT Sensor showed 24 on scanner... I guess 24 ohms.

FRP while cranking, 29.6 to 43.9 psi. After start, 38.7 to 40.5 psi.

The car is still in closed loop mode because I had the battery out to charge recently. So I have the P1000 DTC. Only 3 monitors are complete. Misfire, Fuel, & Component Monitor.

So for now, I'm back to just the amber warning message CATS Fault, ABS Light, & flashing DSC Light.

Still have the ABS-related C1155; C1233; C1145 DTCs. See...
https://www.jaguarforums.com/forum/s...1/#post2476016

Still don't understand the correlation between heating the ECT, and it starting.

 

Won't help, but not the actual problem.

Not likely!! More likely 24C.

Probably Open Loop. Once warm, probably goes CL. Check via OBD.

It fuels depending on temperature.

 

I'm going to dump a few gallons of 93 octane in.

The ECT reading was when engine was cold. It was 9° Celsius out. I was thinking it was reading ohms. I'd have to look at chart for where the ohms should be at 9° Celsius because it should read 2437 to 2464 at 20° Celsius.

Here... I think I found it... at 10° Celsius, the ECT resistance should be 59 kΩ. So, I don't know what the 24 reading was on the scanner. It gave no symbols, just a 24.

The Loop... on scanner it showed ○L. Whatever that means. I saw circle and thought it means closed, cause the circle is closed.

 

Seems a very weird scanner. I could not trust it. An elm327 is cheap instead.

If it does think 24 is 24C when it should be 9 then clearly that is not going to help an engine to run!!