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In order to close the starter solenoid, relay the ignition positive relay in the corner of the right engine bay fuse box must close . this will be point 32 double hash circle ( fuse # 12 / 10 amp right engine bay fuse box )
This power source must pass through the Papa Indy 1 connector which was subject of a TSB on the connector corrosion
68 square is fuse # 3 / 25 amp left engine bay fuse box which the fuse is hot at all times
I have my BPM exposed and can read what I get on the Light Green / Black wire to the ECM as there is some confusion on which of the 2 BPM connectors on the wiring guide picture page 25
This will be a resistance reading as I have no tools for digital , retired from job
Although the triangle symbol for the Light Green / Black wire does not have a D in it for a digital signal I would suspect the signal is in fact a digital
I don't think that's the case. According to all of the manuals and diagrams, the signal from ECU to BPM is a voltage signal (either B+ inactive, or Ground when active).
You're right that the immobiliser signal is digital - but that goes to the Security module. The security module returns a digital signal to the ECU and the ECU is then providing the Voltage signal to the BPM.
I don't think that's the case. According to all of the manuals and diagrams, the signal from ECU to BPM is a voltage signal (either B+ inactive, or Ground when active).
You're right that the immobiliser signal is digital - but that goes to the Security module. The security module returns a digital signal to the ECU and the ECU is then providing the Voltage signal to the BPM.
That's my understanding anyway.
Hello again!
Now i am back with the car for the weekend. I have done the following: checked the voltage between ground and the ecu pin, it was indeed B+ 11+ volts =immobilised?
I moved on to the bpm and forced ground into the mentioned pin. I was glad to see the CEL light up signaling no immobilisation but the joy was short lived as it would still not crank. I don't think I hear the starter relay clicking but I will try to get another person to turn the key for me so I can really know.
Side note: When ignition is turned on I hear a buzzing from LH engine bay. Is this normal?
I will send a pic roughly where the noise is and the rest of what I've done.
Thanks again for the help it means alot.
I feel the noise vibration about where my finger are pointing. Ground into the bpm pin. CEL no crank ECU pin B+
I should have been clear with my previous posts, but all of your measurements need to be taken with the connectors in place on the Modules (ECU and BPM) by back-probing the connector. i.e. placing your test lead in to the back of the connector (the cable side). To do this you will need some Needle Probe leads for your multi meter, or you can use T Pins in the connector and then attach crocodile clips to them.
Try the tests again using this method and let us know.
I suspect the buzzing may be the IACV and if so is normal. Whatever it is, don't worry about it for now as it will have nothing to do with the check engine light that you need to keep focus on.
I should have been clear with my previous posts, but all of your measurements need to be taken with the connectors in place on the Modules (ECU and BPM) by back-probing the connector. i.e. placing your test lead in to the back of the connector (the cable side). To do this you will need some Needle Probe leads for your multi meter, or you can use T Pins in the connector and then attach crocodile clips to them.
Try the tests again using this method and let us know.
I suspect the buzzing may be the IACV and if so is normal. Whatever it is, don't worry about it for now as it will have nothing to do with the check engine light that you need to keep focus on.
I suspected that the connectors should be connected and I will see if I have something fitting for the measurement tomorrow. The noise has always been there i just thougt i'd mention it incase something was up.
May be the cruise control pump located under the air filter box , can be ignored for now
Do you mean that the noise might come from there? because my Cruise control does in fact not work.
It's one of the non-critical issues on the car that i hope to fix but until I get it to start I dont feel like it's worth it to focus on other issues .
1. It can be confusing to identify the correct pin when back-probing and using the electrical diagrams for pin numbers. Always cross check with the wire colour of the pin cable, and the neighbouring pins to verify you have the correct one.
2. If B+ is really 11.3v then you should charge up your battery.
3. A small paperclip or a sewing needle may be useful to use if you don't have T pins or Needle probes
1. It can be confusing to identify the correct pin when back-probing and using the electrical diagrams for pin numbers. Always cross check with the wire colour of the pin cable, and the neighbouring pins to verify you have the correct one.
2. If B+ is really 11.3v then you should charge up your battery.
3. A small paperclip or a sewing needle may be useful to use if you don't have T pins or Needle probes
Now I've redone the tests with backprobing and connected connectors. The ecu pin reads the same positive about 11.3 V which is a bit weird because I have the car connected to a smart charger over time so the battery is fully charged.
With the bpm connector now connected and the pin backprobed with ground the starter engages!
However the engine does not turn over so I guess something is still inhibiting the fueling.
A new light also popped up on the dash, (Top left). As I understand it, it's some form of automatic transmision warning. This has popped up and gone off before. As the engine does not turn over i can't see if it would dissappear or not after start. Could it have something to do with the engine start or is it completely separate? 11.3v ECU pin Fully charged battery Top left new warning light.
Can you just clarify what you are actually seeing now. You say the Starter engages but it does not turn over. To me, Starter Engaging, Turning Over, Cranking all mean the same thing, i.e. the engine is turning on the starter motor.
Starting, Firing Up, Lighting Off all mean the same to me to, i.e the engine runs. Which do you have?
Just to be clear on the forced ground to the BPM - that is not by-passing the immobiliser totally. The ECU will still be inhibiting fueling. The test was just to prove the rest of the starting circuit. So you prove the BPM, Starter Relay, Starter Motor and Solenoid, Starter Cable, Park/Neutral Switch etc. etc. so they can be ticked off your worry list.
On the 11.3v, do a test of the voltage at some key points - Battery itself, Engine Bay fuse box main terminals L & R, Alternator post, Starter Post, and see what readings you get.
Can you just clarify what you are actually seeing now. You say the Starter engages but it does not turn over. To me, Starter Engaging, Turning Over, Cranking all mean the same thing, i.e. the engine is turning on the starter motor.
Starting, Firing Up, Lighting Off all mean the same to me to, i.e the engine runs. Which do you have?
Just to be clear on the forced ground to the BPM - that is not by-passing the immobiliser totally. The ECU will still be inhibiting fueling. The test was just to prove the rest of the starting circuit. So you prove the BPM, Starter Relay, Starter Motor and Solenoid, Starter Cable, Park/Neutral Switch etc. etc. so they can be ticked off your worry list.
On the 11.3v, do a test of the voltage at some key points - Battery itself, Engine Bay fuse box main terminals L & R, Alternator post, Starter Post, and see what readings you get.
Sorry for being unclear. The starter spins but the engine does not fire and so when turning back the key the engine is dead. So the starter circuit works but the fuel is still inhibted by immobiliser.
I will go back and measure the voltage on the mentioned points.
But now that we know the starter circuit works what would be the next step? Can I bypass the fuel inhibition in some way?
I've suspected that there is something wrong with the security module because sometimes it does not want to lock/unlock with the fob and obviously this starter immobilisation is security related.
This does however not explain how i could unlock the immobilisation by fiddling with the cables under the steering wheel before.
Agreed, it looks like it's the immobiliser. But that's a tricky thing. I will have a look later this evening at what things could be tested with basic tools. I still suspect there could be a broken wire somewhere and that's what we need to confirm or eliminate.
Ignition iis powered by the large ECU controlled relay ( right # 5 ) and can be swapped as a couple have the same 7606 number like a headlight
With the starter spinning we can look at the fueling
There is no fuel pressure test point readily avail so we work around that
With initial ignition key rotation, the # 1 fuel pump only comes on for 3 seconds only then off
The fuel pressure will be trapped in the fuel lines by a check valve in each fuel pump and the fuel pressure regulator
It will come back on when the CKPS seee engine rotation for the duration of your drive , safety design
So you will get 3 clicks of the # 1 fuel pump relay .on - off - on
Your # 2 fuel pump will not come on until 4000 RPM
Some details or modes of failure are ......................
Inertia / crash switch can trip for no reason ,it can be bypassed with a paper clip between the 2 white wires on the connectorr
battery must remain in a good charged state
eiting
update. I do not hear the 3 second initial fuel pump. This is something ive always heard even whene there was no CEL (immobilised). I have jumped the inertia switch but it made no difference.
I also found what makes the noise in the engine room i will attach a photo, i unplugged It and It went silent then plugged it back in. Close up
02-28-2023, 07:17 AM
