Mil & t4
 

Posting on behalf on an owner in Stockholm whose 2003 V6 is playing up - misfire on No.2 cylinder with MIL light on, changed plug and pencil coil but fault remains. Owner doesn’t know of any fault codes, just what the garage told him about No.2 cylinder. He hasn’t been able to find any T4 equipped garages locally.

Will the MIL light go out as soon as the fault is rectified or does it need a number of start cycles ?

If there’s a wiring fault can a T4 identify where this fault is or are there any multimeter checks a home mechanic could do? I mention the T4 as I know where one is (or was) but no-one knows how to drive it and it’s up in a garage attic gathering dust.

Regards

Get it out of the attic and set it up, its pretty straightforward to read the issues when a misfire occurs.

Mike,

I had a misfire last year. The MIL didn't illuminate. T4 identified no. 5 but that's as far as its diagnosis goes. It simply lists every connector in the circuit and suggests that they're checked; useless really! The most likely culprit was the ignition coil and that proved to be the case.

Since you have no fault code and renewing the coil and its HT connector has not been successful, a T4 session would at least confirm or otherwise the no. 2 diagnosis.

Simon

Thanks guys, the T4 belongs to a local garage. I’ve known about the machine for some years and even offered to buy it from the previous workshop owner but his indecision and the release of TOAF meant that I lost interest.

If indeed as Simon says it merely lists the connectors in that circuit then it’s not that more than I can do with TOAF and the electrical library - if I could understand the modern circuit diagrams. No problems in the SD1 days but the layout seems to have changed and mystifies.

I’ve read the following by BigRuss: You can check the ECM outputs for the coils C0913 Pin 26 ignition coil (2) earth 0-12V, and Pin 52 ignition coil (1) earth 0-12V (digital meter)
On ECM connector C0371 pin 1 ignition coil has a PWM signal, Pin 15 is the earth for the Engine coolant temperature.
A short circuit or line break for the coils will light the MIL.

Presumably and with my el.library out in the garage, C0913 refers to the ECM connector, but does the bracketed (2) refer to two leads ? Should I expect 12v earth on these pins with the ignition on ?

Would also be helpful to know whether we can expect the MIL light to go out when the problem is sorted, or does it require several start cycles?

Doesn’t help that the owner is two hours away and I’ve not even seen the car, just trying to help him as best I can.

Mike

Hi Mike,

This might be of assistance.

My copy of RAVE gives the ECM connector as C0371. Physically this is two connectors which are "incorporated into one main connector". The total number of pins listed is 90. I haven't been easily able to locate C0913.

Ignition coil no. 2 is connected to ECM pin 62 using a black/green wire. All coils also have a direct earth connection as well as a 12v supply from the main relay via the brown/pink wires.

RAVE advises that there are many possible reasons for a misfire in the areas of ignition, fuelling, electrical, cranksahft sensor, mechanical and air restriction or leaks.

In the circuit description the MIL is mentioned but any requirement to complete ignition cycles following repairs is absent. I think it's reasonable to assume that it will extinguish immediately.

Simon

Thanks Simon, just brought in my copy of the electrical library from the garage, C0913 is the connector for the ECM on the 1.8, and I now see C0371 is, as you say, the connector for the KV6.

So we've got a black/green going to No.2 coil, I can at least check for continuity as well checking the 12v supply and earth connection - progress, gives me something to look at so many thanks.

Mike

ps Just found this post by BigRuss https://the75andztclub.co.uk/forum/s...ad.php?t=97817 where he talks about three drive cycles to reset the MIL.