where does relay 109 gets the power from

alh 99.5 wont fire it up, new relay 109, took realy 109 out and checked constant power , where does relay 109 get the power from? is it from battery fuses on top of the battery? any help

From my project Conversion notes...

This should be all you'll ever want to know...

Relay 109 and associated Circuits (Based on 2002 Jetta TDI)

Located at Position 12 in the upper relay panel
Relay 109 is identified as J317, Power Supply from Terminal B+ (hot at all times) with power activation to the ECU when the key is in the ON position.

Power Circuit to Relay 109
1. Power (6.0 size red wire) comes from Fuse S176 (110amps) at the plastic box on battery to Threaded Connection 500 at the relay plate -1- (30).
2. From the Relay Plate, at Connection 501 (not 500) the power (6.0 size red wire) goes to Splice A98
3. From Splice A98, the power (4.0 size red wire) goes to Terminal 2/30 of Relay 109

Relay Circuit (activated when the Ignition is turned ON) <<<<<<<<<<
1. Connection 9/85 goes to Blue Connector T10h/8 on to ECU at T121/18 (So, another power source to the ECU provides the current to Activate the Relay 109 which in turn activates the rest of the ECU.....make sense?)

Power Circuits away from Relay 109
1. Power away from Relay 109 (Terminal 6/87) is via 4.0 Blue Wire to Splice A71
2. At Splice A71, there are three circuit branches (A, B, & C, my terminology)
Circuit - A. 1.5 Wire goes to Fuse 34 (10 amp)
Circuit - B. 4.0 Wire goes to Fuse 32 (30 amp)
Circuit - C. 1.5 Wire goes to Fuse 43 (10 amp)

Circuit A (with two branches) ........ engine operation functions
From Fuse 34 goes to Splice 100, first branch provides power to: MAF (G70), Wastegate Bypass Regulator Valve (N75), EGR Vacuum Solenoid Valve (N18) and Change-over Valve for intake manifold flap (N239) Note: tied to this same circuit, is another circuit with a 1.0 size wire that goes to connection 6/87 of the GP relay. The second branch , Splice 100 goes to the 14 Pin Connector at T14a/6 on to Cold Start Injector (N108)

Circuit B (with two branches)
From Fuse 32 goes to Splice B168, first branch (4.0 wire) goes to Brown Connector point T6/4 on to splice D74 and provides power to: ECU at T121/1 and T121/2 via the two branches at Splice D74. The second branch goes to the 10 pin connector at the Injection Pump (G149), connection T10f/5

Circuit C (with three branches)
From Fuse 43 goes to Splice A155 , the first branch goes to Clutch Vacuum Vent Switch (F36). The second branch (page 10) goes to Brown Connector at T6/6 with double wire of which one goes to a 53 Relay J359 for Low Heat Coolant GP and the other goes to the Positive Crankcase Ventilation Heating Element (N79). The third branch goes to the Brake Vacuum Vent Valve Switch (F47)

(Below), Not part of the 109 Relay circuits that go to the ECU

Fuse 37 (15amp) - circuit to ECU 121/8, 0.35mm wire. The power comes from Terminal 501 on the relay plate (always hot) (This circuit was added/started in November of 2001.). Prior to that date, Fuse 37 had other functions, such as radio.

Fuse 29 (10amp) - circuit goes directly to ECU 131/37, 1.5mm wire. The power is from D15 in the ignition, Key On, provides power to the ECU.

Exception
Fuse 10 - Does not go to the ECU. Beginning in November of 2001, this circuit goes to the T32/30 at the Cluster. And, it may have also involved the Radio ..........very hard to determine!

everything works at relay 109 socket, blue/yellow wire is grounded, I get constant 12v Red wire, blue wire gets 12v when switch is on, and at fuse box fuse 29 gets power when key is switched on, but I am NOT getting power to fuse 32 when key is switched on, which I believe it trigers ECU and iP Solonoid current, any help here

My working papers are from May 1999. So, I assume they cover the 1999.5 ALH.

So, Fuse 29 is not powered by Relay 109.

Fuse 29 is powered from the D/15 of the Ignition Switch. Fuse 29 powers the ECU directly at T121/8.

The circuit also powers Fuses 5 and 7 ... which from there gets more involved than I want to type up here. But, those two fuses involve the VSS, Cruise, OBD, Fresh air controls, etc., to name a few.

So, in my opinion, Relay 109 or its circuits are not the issue!

Maybe a bad ignition switch..

Andy thxs for helping me i really appricate but i wrote that im getting power at fuse 29 (but im not getting 12v at fuse 32) when switch is on, where is fuse 32 getting it from the ignition switch as well? Thxs,ahead

Sorry, apparently I was reading too fast and misinterpreted your statement.

Fuse 32, gets power from the Relay 109 Circuits as described in my first post.

The Single Big Blue wire (power away (leaving) Relay 109 goes a short distance to a factory splice. At that splice (labeled as Splice A71), the Big Blue wire splits into three circuits..... Those three circuits provide power to Fuses 32, 34 and 43.

So, I doubt the splice is bad.

Do Fuses 34 and 43 have 12 volts?

Back up some here. Does the MIL and glow lamp come on when you turn the key on, yes or no?

If yes, then the ECU is powering up. Next step would be to check for crank RPM signal with a scan tool during cranking. I would actually first make sure no DTCs are present while in there, just to rule that out. But a dead CKP sensor will not set a DTC but will show "0" RPM during cranking if it is not sending a signal.

Rpm is not moving, glow plug light is on, ecu is not fried, got a back up one and does the same symptoms, and to make sure i installed another ecu with stock parameters and does the same thing. Now turbo actuator does not move when switch is on, so im trying to get to the bottom and as of now Andy, im away from golf for a couple days i will check on the other fuses and see if they have current when i get back home,

Oilhammer
CKP sensor=crank sensor? Sorry for my ignorance

I should've described the sympthon of my golf from the begining, my bad, car drove fine then i parked it home next morning it would not start, got fuel going , do not have power at IP solenoid when switched on, rpm does not work, glow plug light on, i did the micky mouse to power the solenoid with a wire connected from battery, sometimes it fires up for 30 seconds then dies, and i see that a actuator does not move, so i am partially not having a lot of sensor not being triggered, golf has left me stranded in the past i must've had it on the tow truck at least 4 times, so now i decided to find the the culprit here, thx for all your help

The power drops off at the IP solenoid once the ignition is turned on. I've proved that with my ALH Van and my 2000 Jetta. The power (initially 12+ volts) will rapidly drop to less than 2 volts when the ignition is turned ON (I have photos for documentation). Thus, turning ON the ignition walking out front and placing a multi-meter on it to check voltage will give you a false reading/impression.

The Solenoid (N 109) receives it's power directly from the ECU, Pin 121/120. If you jump power to the Solenoid without disconnecting it, current will back-feed to the ECU. This procedure can "by-pass" an electrical issue back upstream, thus, possibly allowing the engine to start.

The Actuator doesn't come into play with starting the engine. Without vacuum, it is not going to move anyway. Once the engine fires and there is vacuum produced by the pump, the Actuator arm is pulled down fully against the set-screw. But, none of this has anything to do with the engine starting properly.

You need to confirm whether or not all three of those Fuses (32, 34 & 43) have 12 volts. All three of them provide power to "key" components with respect to starting and running the engine as outlined in my initial post!

When you crank over the engine, if the RPM (Tach) shows zero, then, the sensor is most likely the culprit as Oilhammer indicated. The Engine Speed Sensor (RPM) is located below and to the right of the Oil Filter Housing on the block near where the transmission mates to the block. The wire leads up behind the IP and plugs to the big wiring bundled there. Other than observation on the Tach, I do not know of any way to test it. However, if certain parts of the ECU are not getting power due to one of the Relay 109 circuits being bad, then, the RPM sensor may not function.

Again, I say do the simple first.... check the power coming off those three fuses !

If there is no cranking RPM being displayed in the data block via scan tool, then the engine will not start. Period. The ECU sees no rotational RPM, so it will not deliver any fuel.

CKP = crankshaft position sensor, or G28 engine speed sensor. Located in the block, the wire is about a foot long and goes to a gray connector in the same holder where the #3 injector lift sensor wire connector sits, as well as the injection pump connector.

So fuses 32 34 43 needs to have constant current? Or when ignition is on?

When the ignition is turned ON, D15 of the Ignition activates the ECU, then the ECU activates Relay 109.

At that instant, all three of those Fuses "should" have at least 12 volts on them. Refer to the info I posted. It is really not that complicated. I put that info together in order to understand how to install a 2002 ALH in my Vanagon.... it is accurate info!

so now I did check and fuse 29 got power, but I do not NOT have power on 32 34 and 43 when switched on, I also noticed now that glow plug is not coming on now, it was before though, so most likely it is not communicating with ecu, and thxs about crank sensor explanation, I do know where it is located and I changed quite a few through out the years, I just did not know what CKP meant,,,,, now 109 got all the power needed with the grounds so it is definitely NOT the relay109,, could the culprit be the ignition switch now?

Well, I did think about the ignition switch as a possible source of the issue!

D15, one of several circuits coming off the ignition switch, is very important. Without digging back into those schematics, as I recall, Fuse 29 provides power to a number of things besides the ECU.

The Glow Plug Relay has a big red wire from the battery (one of the flat fuses on top of the battery). It has a ground, two connections from the ECU and one connection from Relay 109 through Fuse 34<<<<<<< So, if you have no power on Fuse 34 the GPs are not going to operate.

Double check Fuse 29 for power... if no power, the suspect has to be the Ignition as you suggested!

I double checked and fuse 29 got power, so you are advising me that i should check for grounds, since fuse 32 34 and 43 are dead no current.

I ordered the crank sensor just in case like oilhammer suggested., any more suggestions would be appreciated

The Circuits to and away from Relay 109 are fairly straight forward.

-Big Red Wire provides power to 109 (from Fuse 176 (110 amp) on top of the battery, flat silver color)
-Big Blue Wire sends power away from 109
-There is a splice in the wiring harness that breaks the Big Blue Wire down to three Circuits, one for each of these Fuses 32, 34 and 43.

There is one other wire (small) to 109 from the ECU (non-fused). That circuit activates 109 when the Ignition is turned On. That circuit goes through connector T10h/8, which I do not think would be the problem (the connection).

Of course, all those wires are on the back side of the panel and quite hard to access.

Yes, grounding can be a problem. However, I seriously doubt there is a ground issue causing no current on those three Fuses.

Considering Relay 109 is very inexpensive, I'd try another one for confirmation!

Got 3 relays, grey color and i tried them all

Let me go again Andy and double check blue wire at relay 109, if i got current then the culprit may be wire broken off between R 109 and fuses then

check for key on power on the blue wire at the relay, if you have power there then check for power @ the three fuses... if no power you have a break between r109 and fuses... the crimp splice is in the main fuse box taped bundle... another thing to check is the actual terminal in the r109 base, the terminals can push out and lose connectivity to the relay

ok so blue wire now does NOT have current when switch is on, this happened probably since my glow plug light stopped blinking when I tried firing her up about a week ago, so now what could the culprit be the ignition switch or grounds?? I had 3 Relays 109 even the one from my jetta that works so no relay 109 is at fault,, Andy you have the crystal ball rub it and tell me pls, and thx you so much for all your help along the way.

Don't post pics with Photobucket unless you are willing to pay the $400 fee for 3rd party posting rights. Please try and use the sites photoserver if possible. As you can see we can't see anything.

I haven't posted anything. Do not know what you are talking about

Lightflyer1 said:

Don't post pics with Photobucket unless you are willing to pay the $400 fee for 3rd party posting rights. Please try and use the sites photoserver if possible. As you can see we can't see anything.

Click to expand...

it's the photo in his signature are that your confusing with a thread related pic... got me a few times too

Relay Circuit (activated when the Ignition is turned ON) <<<<<<<<<<
1. Connection 9/85 goes to Blue Connector T10h/8 on to ECU at T121/18 (So, another power source to the ECU provides the current to Activate the Relay 109 which in turn activates the rest of the ECU.....make sense?)

MAXRPM said:

Relay Circuit (activated when the Ignition is turned ON) <<<<<<<<<<
1. Connection 9/85 goes to Blue Connector T10h/8 on to ECU at T121/18 (So, another power source to the ECU provides the current to Activate the Relay 109 which in turn activates the rest of the ECU.....make sense?)

Click to expand...

yes, small wire from ignition switch key on/start wakes up the ecm which in turn grounds the relay 109 which THEN sends main power to the ecm, various solenoids, and injection pump

I ordered the ignition switch, I'll be installing it when it arrives with crank sensor, hopefully this will fix the issue, ill keep you posted knock on woods

Sometimes the connector shell at the ignition switch is melted, and you need to make a new connector "pigtail" with the repair kit wires, a new shell, and splice it in.

Here's what i found when I had a similar problem. I'd checked everything you have already and finally I found that if I pulled the relay holder from the bracket underneath and inspected it, the blue (iirc) connector in the socket had been pushed into the socket to the point where contact was intermittent with the 109 relay. Was able to push it back into the socket so positive contact was held, haven't had a problem yet. It's been about a month now.
Good luck.

installed new ignition switch, at first did not have glow plug light on, so no power to fuses 32 34 and 43, I swapped to a different ecu from RC6 to RC7, still did not have any current, and obd2 was not communicating with either RC6 or RC7 through vag.com, pushed ecu plugs in and messed like for 10 minutes, got the plastic tabs outs and pins and wires exposed at ecu , continued to messed with ecu cables I went back and forth and finally got it to communicate with obd2 and lap top, glow plug blinking light came on dashboard, fuses 32 34 and 43 got power, but I knew that this blinking light had been working when I 1st posted this thread and I was not going to call it victory yet, until golf fires up, cranked for a while and nothing , so now I am at square one, got current and ecu is communicating but it is not firing up, like when I 1st posted, it is better than not having current but it is not running. (I haven't changed the crank sensor yet)

Codes that I got on ecu are

1) Accelerator position sensor (G79) Implausible signal
2)Intake pressure sensor (G71) Short to plus-Intermittent (I got no EGR)
3)Intake manifold temperature sensor (G72) open or short to plus
4)Solenoid Valve for boost pressure control (N75) open or short to ground

I cleared these codes and they came back.