R33 Fuel Pump & Brakes after alarm swap

[Jarsky]

Thought I would get some advice from others on this situation. 

 

Relevant info:
R33 GTS25t
Link G4x ECU
Walbro 255LPH w/ OEM FP Relay (No relay mod)

Scenario:

I accidentally messed up my old AVS S5 (rev.1) at the start of the year and the cars been immobilised. Also the siren BBU has completely failed; so I decided to upgrade it. 
I got a newer AVS S5 (rev.2?) installed on Friday. The guy removed the old one and its immobilisers. Tried to start it; the car cranks but doesnt start. 
The new one was installed and all the alarm functions seem to be working as they should; still wouldn't start

Went to bed; got up on Friday morning and decided to have a look into the no start problem. Found the car completely dead. 
Charged the battery; plugged it back in and found the brake lights were stuck on. 

Unplugging the brake pedal switch the lights turn off. Plug it back in and theyre stuck on again. I tested the switch (continuity test and resistance); all looks good (0-1kohm). 
On talking to AVS; found its because of the rubber stopper on the brake pedal; sure enough the middle of it is missing so have ordered a new one. One of those wear items; which was confusing what was going on

However when I try unplugging the STOP Light fuses (under the dash and under the hood) the brake light still stays on. Should those fuses not cut the brake light circuit? 
I then checked the ECU; FP Speed Error. 
Testing the pump again; I can hear the relay clicking every time I switch it to ON. I unplugged the pump and put the multimeter across the plug. No continuity; im seeing 0.6V (ECU signal?) and when it switches the relay I think its like 20mA or 200mA). Not seeing 12.4V / 7-9A.

As far as I know; the Fuel Pump was wired through one of the immobiliser relays on the old alarm. 
He pulled some thick gauged harness out with the old alarm wiring; which looks to me like it was to bridge connections into the immobilisers?

Before it got immobilised it was running just fine. 
Im at a loss to why the FP is getting no voltage; I thought maybe the FP was faulty (even though I havent even done 50km on the new pump) but no voltage at the harness plug. 

Questions:
Could it be he didnt reconnect the fuel pump when testing it after the old alarm removal (before installing the new alarm)? 
Is this a case of bridging to the brake lights instead of the fuel pump circuit?

It's a bit beyond me as I dont do a lot with electrical; so have tried my best to diagnose what I think seems to make sense. 
Seeking advice if theres for sure an issue with the alarm install to get him back here; or if I do infact, need an auto electrician to diagnose it. 

[GTSBoy]

Look, realistically, those are some fairly chunky connectors and wires so it is a reasonably fair bet that that loom was involved in the redirection of the fuel pump and/or ECU/ignition power for the immobiliser. It's also fair to be that the new immobiliser is essentially the same thing as the old one, and so it probably needs the same stuff done to make it do what it has to do.

Given that you are talking about a car that no-one else here is familiar with (I mean your exact car) and an alarm that I've never heard of before and so probably not many others are familiar with, and that some wire monkey has been messing with it out of our sight, it seems reasonable that the wire monkey should be fixing this.

[MBS206]

Who did you have do the installation?

I actually know someone who is VERY familiar with the AVS gear. The main point of contact though would be your installer.

 

Where are you based in NZ?

[Jarsky]

3 hours ago, GTSBoy said:

Look, realistically, those are some fairly chunky connectors and wires so it is a reasonably fair bet that that loom was involved in the redirection of the fuel pump and/or ECU/ignition power for the immobiliser. It's also fair to be that the new immobiliser is essentially the same thing as the old one, and so it probably needs the same stuff done to make it do what it has to do.

Given that you are talking about a car that no-one else here is familiar with (I mean your exact car) and an alarm that I've never heard of before and so probably not many others are familiar with, and that some wire monkey has been messing with it out of our sight, it seems reasonable that the wire monkey should be fixing this.

Its a well known brand in New Zealand; its a rebrand of the Rhino RAV3. 
I don't know what the wiring difference *is* between the rev.1 (installed about 15 years ago) and rev.2; but as you say I would think its reasonable that it uses the same immobiliser relay circuits. I had a look but couldnt see a similar harness; but didnt move things around since I didnt want to mess with it

 

2 hours ago, MBS206 said:

Who did you have do the installation?

I actually know someone who is VERY familiar with the AVS gear. The main point of contact though would be your installer.

 

Where are you based in NZ?

It was one of AVS well known Authorised Installers; I spoke to AVS themselves about it but theyre unsure hence seeking advice more so from the skyline community who are more familiar with the actual car and its wiring. Im in Auckland; but the installer is on the other side of the city so hes very reluctant to come back to even look at it to confirm something isnt connected into the wrong wire. 

I dont want to drop the name since they *did* do a really good job for the most part. Everything is very tidy and he fully replaced all the alarm wiring, all the sensors, the wiring to the door motors, installed a switch which was never installed in the first place...really happy with the alarm install itself..just not this one issue. We all make mistakes, if it is the alarm, I just want my fuel pump getting proper switched, fused, power as it was; without having to shell out for an auto electrician to switch a wire and tell me it was the alarm. 

Edited Wednesday at 07:45 AM by Jarsky

[GTSBoy]

Well, this is probably where a wiring diagram and a multimeter come into play.

[MBS206]

Either the installer needs to come back, you need an auto electrician, or you need to learn automotive electricals yourself.

 

First step Id look at is where that big thing came out of, is there still things unplugged at that location?

Maybe they just forgot to put a relay in or something?

[Jarsky]

2 hours ago, GTSBoy said:

Well, this is probably where a wiring diagram and a multimeter come into play.

Well this shows me the fuel pump relay is inside the base of the drivers A Pillar, and goes into the main power wire, and it connects to the ignition. The alarm is.... in the base of the drivers A Pillar. The issue is that I'm not getting 12v to the pump at ignition which tells me that relay isn't being triggered. AVS told me the immobiliser should be open until the ignition is active. So once ignition is active, the immobiliser relay should be telling that fuel pump relay to close which completes the circuit. But I'm not getting voltage at the relay in the rear triggered by the ECU, which leaves me back at the same assumption that that relay was never connected into the immobiliser. This is what I'm trying to verify, that my assumption is the most likely scenario and I'll go back to the alarm tech yet again that he needs to fix his work. 

 

 

Here is the alarms wiring diagram, so my assumption is IM3A, IM3B, or both, aren't connected or improper. But this is all sealed up, with black wiring, and loomed

 

Edited Wednesday at 11:27 AM by Jarsky

[GTSBoy]

When I said "wiring diagram", I meant the car's wiring diagram. You need to understand how and when 12V appears on certain wires/terminals, when 0V is allowed to appear on certain wires/terminals (which is the difference between supply side switching, and earth side switching), for the way that the car is supposed to work without the immobiliser. Then you start looking for those voltages in the appropriate places at the appropriate times (ie, relay terminals, ECU terminals, fuel pump terminals, at different ignition switch positions, and at times such as "immediately after switching to ON" and "say, 5-10s after switching to ON".

You will find that you are not getting what you need when and where you need it, and because you understand what you need and when, from working through the wiring diagram, you can then likely work out why you're not getting it. And that will lead you to the mess that has been made of the associated wires around the immobiliser.

But seriously, there is no way that we will be able to find or lead you to the fault from here. You will have to do it at the car, because it will be something f**ked up, and there are a near infinite number of ways for it to be f**ked up.

The wiring diagram will give you wire colours and pin numbers and so you can do continuity testing and voltage/time probing and start to work out what is right and what is wrong. I can only close my eyes and imagine a rat's nest of wiring under the dash. You can actually see and touch it.

[Duncan]

I feel like I'm missing something.

You had an authorised installer come out and install a new alarm. Post install the car doesn't start, and you aren't getting the installer back to fix what they did wrong?

[Jarsky]

I was using the wiring diagram I have

So 12.74V is coming into the rear Fuel Pump relay as I measured. 
When I turn the key to ON im getting 0.6V to the Fuel Pump plug; which i assume is backfeed voltage and doesnt include the 12V from ignition power. 
The rear relay is working and being triggered. 


From the diagram I clearly see the rear relay

80 = Rear Relay going into the Body/H loom (R-27)
27 = Fuel Pump plug going into the Body/H loom (T-20)
40 = Short Connector (R-27)

I'm reading 12.74V on the blue/black wire which is the power for the Fuel Pump

 

From this diagram I can see the Ignition relay goes into the front and up to the ignition 

2 = Fuel Pump Relay <1M> (R-27)
37 = ING Relay <1M>

I started from the pump using this reference

Which the way I read it (referencing Nissan wiring color codes) is:

Pin	Wire Color	Function
1	B/P (Black/Pink)	Ground
2	L/W (Blue/White)	ECU Trigger
3	SB (Sky Blue)	Fuel Pump
5	L/B (Blue/Black)	12V Constant

• Tested SB to SB on Fuel Pump for continuity - confirmed
• Tested negative on Fuel Pump to 12V battery and L/B - confirmed 12V
• Pulled the relay putting 12V between Pin 1 & 2 and testing continuity on Pin 3 & 4 - confirmed relay

 

So that has me looking at this part of the circuit to understand whats happening here...and im still confused.

From best I can tell; the disconnect is back to my previous diagram; between Ignition Relay and Fuel Pump Relay...which yet again; afaik is where the immobiliser should. 

 

1 hour ago, Duncan said:

I feel like I'm missing something.

You had an authorised installer come out and install a new alarm. Post install the car doesn't start, and you aren't getting the installer back to fix what they did wrong?

Thats what I was trying to explain to GTSboy; im not trying to fix it myself; yet I seem to have to get a Masters in Electrical Engineering (while im busy doing my actual job of DevOps & Cloud Engineering) somehow.  I just wanted more expert opinions; or more so that what I tested is correct and proves it to something around that area; to go back to the alarm tech (for a 3rd time) that he needs to fix it. He keeps telling me its not the alarm. He lives on the complete other side of the city so i understand not wanting to make a trip but as I said before if its the alarm it should be up to him to fix it. But he's adament its not; even though I pointed out the FP was immobilised through the original alarm. To my mind; it seems that the ECU is sending the signal; but the ignition is not getting 12V down the line. 

 

 

 

Edited Thursday at 11:44 PM by Jarsky

[MBS206]

If the FP immobiliser relay is in that APillar, open the APillar up and have a look.

It might be as simple as, someone forgot to put a relay in the relay holder.

 

Also when testing for the power/signal to activate the relay, are you doing this with just the key turned to on? If so, the ECU turns the FP off after about 3 seconds if the engine is not actually running (RPM > 0).

Also, unplug the actual fuel pump, and measure if you're getting 12V to the plug of the fuel pump. Removing the pump from the circuit will remove any variation in worrying about back feed etc etc.

 

I'd still be very much so pushing the installer to come back out. How did he get to leave the site without testing the car could physically start? That sounds like a standard thing to test if you install an immobiliser. "Immobiliser is immobilising, and immobiliser is now turned off, and car starts".

[Murray_Calavera]

27 minutes ago, Jarsky said:

Thats what I was trying to explain to GTSboy; im not trying to fix it myself; yet I seem to have to get a Masters in Electrical Engineering (while im busy doing my actual job of DevOps & Cloud Engineering) somehow.  I just wanted more expert opinions; or more so that what I tested is correct and proves it to something around that area; to go back to the alarm tech (for a 3rd time) that he needs to fix it. He keeps telling me its not the alarm. He lives on the complete other side of the city so i understand not wanting to make a trip but as I said before if its the alarm it should be up to him to fix it. But he's adament its not; even though I pointed out the FP was immobilised through the original alarm. To my mind; it seems that the ECU is sending the signal; but the ignition is not getting 12V down the line.

Was the car running before he touched the car?

[Jarsky]

14 minutes ago, MBS206 said:

If the FP immobiliser relay is in that APillar, open the APillar up and have a look.

It might be as simple as, someone forgot to put a relay in the relay holder.

If you mean the alarm immobiliser; theyre internal to the alarm itself which makes that difficult; I couldnt even see where he put it; its not in the same place as last time; but with all black wiring it might be very challenging to trace 

14 minutes ago, MBS206 said:

Also when testing for the power/signal to activate the relay, are you doing this with just the key turned to on? If so, the ECU turns the FP off after about 3 seconds if the engine is not actually running (RPM > 0).

I had someone turn the key for me as I know it only primes for a couple of seconds

14 minutes ago, MBS206 said:

Also, unplug the actual fuel pump, and measure if you're getting 12V to the plug of the fuel pump. Removing the pump from the circuit will remove any variation in worrying about back feed etc etc.

As my post above; I am getting no voltage to the pump at all; but I am testing continuity of the power line (SB) from the pump plug to the relay fine. As well as the negative from the pump plug to a 12V constant. 

 

14 minutes ago, MBS206 said:

I'd still be very much so pushing the installer to come back out. How did he get to leave the site without testing the car could physically start? That sounds like a standard thing to test if you install an immobiliser. "Immobiliser is immobilising, and immobiliser is now turned off, and car starts".

Yeah; he blammed the no start on a bad battery; said I needed to get a new battery and it'll start. Turns out the battery drained because the tail lights had been on for half the day during the install (the rubber cushion on the brake switch gave out while he was testing it as I have a picture of the car from that morning with the tail lights off..i've replaced that). The battery was turning over the engine just fine for a long time; but got low since lights were draining it so it was too low to test a start after he finished. I bought a new one on his advice...$250 wasted. My original battery charged up just fine and is healthy. 

 

5 minutes ago, Murray_Calavera said:

Was the car running before he touched the car?

It was running perfectly fine when I messed up the old alarm (programmed out the remotes). He couldnt start it after removing the old alarm; my assumption is that when he unhooked it; he didnt bridge the circuit back when trying to start it. Its always been perfectly fine. The ECU swap and pump were 2 years ago. It's never missed a beat in that time. 

[Murray_Calavera]

Did you pay with a credit card? I'd be putting a charge back through then finding a new sparky to sort it out. 

[GTSBoy]

4 hours ago, Jarsky said:

So that has me looking at this part of the circuit to understand whats happening here...and im still confused.

From best I can tell; the disconnect is back to my previous diagram; between Ignition Relay and Fuel Pump Relay...which yet again; afaik is where the immobiliser should. 

Power is fed to the ECU when the ignition switch is switched to IGN, at terminal 58. That same wire also connects to the ECCS relay to provide both the coil power and the contact side.

When the ECU sees power at 58 it switches 16 to earth, which pulls the ECCS relay on, which feeds main power into the ECU and also to a bunch of other things. None of this is directly involved in the fuel pump - it just has to happen first.

The ECU will pull terminal 18 to earth when it wants the fuel pump to run. This allows the fuel pump relay to pull in, which switches power on into the rest of the fuel pump control equipment. The fuel pump control regulator is controlled from terminal 104 on the ECU and is switched high or low depending on whether the ECU thinks the pump needs to run high or low. (I don't know which way around that is, and it really doesn't matter right now). The fuel pump control reg is really just a resistor that controls how the power through the pump goes to earth. Either straight to earth, or via the resistor. This part doesn't matter much to us today.

The power to the fuel pump relay comes from one of the switched wires from the IGN switch and fusebox that is not shown off to the left of this page. That power runs the fuel pump relay coil and a number of other engine peripherals. Those peripherals don't really matter. All that matters is that there should be power available at the relay when the key is in the right position. At least - I think it's switched. If it's not switched, then power will be there all the time. Either way, if you don't have power there when you need it (ie, key on) then it won't work.

The input-output switching side of the relay gains its power from a line similar (but not the same as) the one that feeds the ECU. SO I presume that is switched. Again, if there is not power there when you need it, then you have to look upstream.

And... the upshot of all that? There is no "ground" at the fuel pump relay. Where you say:

4 hours ago, Jarsky said:

 

Which the way I read it (referencing Nissan wiring color codes) is:

Pin	Wire Color	Function
1	B/P (Black/Pink)	Ground
2	L/W (Blue/White)	ECU Trigger
3	SB (Sky Blue)	Fuel Pump
5	L/B (Blue/Black)	12V Constant

and say that pin 1 Black/Pink is ground, that is not true. The ECU trigger is AF73, is black/pink, and is the "ground". When the ECU says it is.

The Blue/White wire is the "constant" 12V to power the relay's coil. And when I say "constant", I mean it may well only be on when the key is on. As I said above.

So, when the ECU says not to be running the pump (which is any time after about 3s of switching on, with no crank signal or engine speed yet), then you should see 12V at both 1 and 2. Because the 12V will be all the way up to the ECU terminal 18, waiting to be switched to ground. When the ECU switches the fuel pump on, then AF73 should go to ~0V, having been switched to ground and the voltage drop now occurring over the relay coil.

3 & 5 are easy. 5 is the other "constant" 12V, that may or may not be constant but will very much want to be there when the key is on. Same as above. 3 goes to the pump. There should never be 12V visible at 3 unless the relay is pulled in.

As to where the immobiliser might have been spliced into all this.... It will either have to be on wire AF70 or AF71, whichever is most accessible near the alarm. Given that all those wires run from the engine bay fusebox or the ECU, via the driver's area to the rear of the car, it could really be either. AF70 will be the same colour from the appropriate fuse all the way to the pump. If it has been cut and is dangling, you should be able to see that  in that area somewhere. Same with AF71.

 

You really should be able to force the pump to run. Just jump 12V onto AF72 and it should go. That will prove that the pump itself is willing to go along with you when you sort out the upstream.

You really should be able to force the fuel pump relay on. Just short AF73 to earth when the key is on. If the pump runs, then the relay is fine, and all the power up to both inputs on the relay is fine. If it doesn't run (and given that you checked the relay itself actually works) then one or both of AF70 and AF71 are not bringing power to the game.

[Jarsky]

Appreciate the correction on the "ground", that will make a huge difference to looking at this. That makes complete sense about AF70/AF71 which is what I had come down to being the issue, one of these. I'll have another look in the ignition wiring when I get a chance next week. I'll also make up a jumper wire for running that AF73 test. 

ECU is fine, relay itself is fine, pump harness is fine and the pump itself is fine. I am going to upgrade the Walbro 255 anyway with a DW300 I have since I need to replace the fuel sender and I'm going to upgrade the FPR with my chasebays kit ready for new plenum/injectors/dbw, but I'll get this working first. That's why this is so frustrating.