VZ Calais: Not starting; fuel gauge error

[NicholasG]

Hey all,

I jumped in the VZ Calais today only for it to not start; it's not even cranking at all. With this, there's a fuel gauge error and there's also very low fuel - but the tank is full. Also, from time to time when it was running, there would be some instances of it not starting on the first time, but removing the key and doing it all over again seemed to work. Prior to today there was nothing to indicate anything was at fault.

I'm inclined to think it's the ECU; however, that's already been replaced about a year ago. Uncannily enough, it not starting and giving the fuel gauge error was the reason the ECU was replaced!

Would anyone have any idea on, A) how to get it started, and, B) what the cause of all this may be?

All help appreciated

Cheers,
Nicholas

 

[99notout]

Here is where you need to test the fuel sender unit, the two centre pins, the resistance should be between 40 and 250 ohms depending if the tank is full or empty. You can expose the 4 wire harness and de-pin the two centre pins and connect a 60 ohm resistor to them as a temp fix to see if the problem is the sender unit. Also check for a break in the harness or short to ground or power.

If it checks out fine, then it's more difficult to help without a hands on.

 

[NicholasG]

Here is where you need to test the fuel sender unit, the two centre pins, the resistance should be between 40 and 250 ohms depending if the tank is full or empty. You can expose the 4 wire harness and de-pin the two centre pins and connect a 60 ohm resistor to them as a temp fix to see if the problem is the sender unit. Also check for a break in the harness or short to ground or power.

If it checks out fine, then it's more difficult to help without a hands on.

Thanks for that, it's great. I gave it a try and it checks out and seems to operate normally. The harness and all wires look pretty good, nothing that would indicate a short.

Something that I didn't include in the original post is that the coolant temperature is 215 degrees.

Looks like it's off to the mechanics. Hopefully it's not the ECU again!

Thanks all the same

Cheers,
Nicholas

 

[99notout]

Something that I didn't include in the original post is that the coolant temperature is 215 degrees.

In Fahrenheit 215 is still below when the thermo fans kick in, that's at about 226, or 108 celsius. So normal operating temperature there, nothing to worry about, unless it thinks it's 215 celsius.

A lot of people just blame the ECU, and they are a bit frail, but as a rule something causes them to fail. It can be heat, but often it's 12v bleeding into a 5v reference cable, or a faulty ground. So try a good auto electrician rather than a mechanic this time.

 

[delcowizzid]

Turn the key on and bridge the start relay with a peace of wire to crank it if it runs ecu is cactus again my mates vz has had 5 ecus for this reason

 

[NicholasG]

In Fahrenheit 215 is still below when the thermo fans kick in, that's at about 226, or 108 celsius. So normal operating temperature there, nothing to worry about, unless it thinks it's 215 celsius.

A lot of people just blame the ECU, and they are a bit frail, but as a rule something causes them to fail. It can be heat, but often it's 12v bleeding into a 5v reference cable, or a faulty ground. So try a good auto electrician rather than a mechanic this time.

I should have said, it's definitely centigrade. The thing is, the car hasn't been started for a few days now, so it's totally wrong. Well this is the second ECU it's had, but the original one was damaged by water. I'll give the car's electrical system a good look over, if I can't find anything I'll give it to an electrician. Cheers anyway

Turn the key on and bridge the start relay with a peace of wire to crank it if it runs ecu is cactus again my mates vz has had 5 ecus for this reason

That's exactly what we did when the first ECU went! The first time -with its original ECU- it fired and ran normally. This time all it does is crank; it doesn't fire at all. Would you happen to know what caused it to go through 5!?

 

[delcowizzid]

Dodgy repairs and second-hand ecus lol

 

[NicholasG]

Dodgy repairs and second-hand ecus lol

Hahaha, yep that'll do it! How's it now?

Also, herewith are a few photos of the dash and some information if anyone knows how to interpret it

Cheers,
Nick

 

[NicholasG]

Just an update;

After a week and a bit, it's finally back from the mechanics. After a PIM, ECU, and $1,400, it's finally fixed.
It turns out that the PIM and ECU weren't communicating with each other and would time-out, thus not enabling the car to start.

Thanks for everyone's help


Cheers,
Nick

 

[Fu Manchu]

I always thought these issues were BCM related.