graniteguru

iTrader: (1)

I have been working on the car for a while. I put an S5 JDM Turbo into an S5 NA auto.

The car has been running, but with with no power when it goes into boost. I found that when I re-wired, the Brown/White wire that goes to the AFM is grounding to the body of the car. In other words, with an ohm meter, it shows continuity between the black/white wire on the ECU and the brownwhite wire.

I spent some time tracking it down, and it only grounds out when the TPS is connected. Is this normal. Does the TPS ground this brown/white wire until the throttle opens or something or do I have the TPS wires crossed or what?

HAILERS

The brown/white wire if grounded won't let the car start. No spark and no fuel injection.

Try something different. Meter to volts dc. Key to ON. See if you have approx 5vdc at the brown/white wire on the AFM plug. Then pull the TPS plug on/off and see if the approx 5vdc stays there or not on the afm plug. For extra work, check to see if you read approx 5vdc on the TPS plug on it's brown/white wire.

You can go to the CONTROL UNIT page that lists the outputs/inputs of the ECU wires. Key to ON or idle and backprobe the wires with the plugs connected to the ECU. I'd do it at idle and check the output of the 2B at the ECU to see if the afm is in range with the figures in the FSM.

If you unbolt the ECU, you can tilt the ECU so you can backprobe the wires easier with??? a needle or paper clip or ????

Pins 3A and 3B on the ECU are grounds but there is another B/W wire at 1B that is 12vdc from the EGI fuse. Just FYI.

Check the TPS outputs at 2G and 2F and compare them to the FSM. Engine hot and idling.

graniteguru

iTrader: (1)

Interesting on the 3rd B/W wire. I may have these tied together. I will check to make sure that it is not going to ground as well. Get back in a little while with the results. Thanks Hailers.

graniteguru

iTrader: (1)

Checked the Volts at the AFM and the TPS. with the TPS plugged in , 4.95 volts on the AFM. Unplugged at the TPS and the reading drops to .25 volts/

HAILERS

See the diagram. The BrW comes out of 2I on the ECU and goes to several items, all tied together. Goes to the TPS, the OMP, pressure sensor and the afm. So if any of those items has a problem inside, the voltage drops for all the items and wherever the 2I goes inside the afm.

So let's say you disconnect all the items except the plug at the ECU. At each brown/white wire on those plugs you should read approx 5vdc. So if you plug one plug in at a time while reading from one of the other plugs, the voltage should not drop any significant amount. If it drops to a quarter volt then that's no good.

Are you saying you have the meter on the brown/white wire at the tps, and when you plug the afm plug on the afm, the voltage at the TPS plug falls from five volts to a quarter volt???????? Or vice versa? I'm missing what your saying for some reason. Whatever item you plug in, and see the voltage at the brown/white wire in one of the other items drop to a quarter volt, then the item you plugged into is bad or miswired.

HAILERS

I don't think this is your problem, but I noticed that, that brown/white wire also feeds the ECAT control unit. The automatic transmission unit. I'd make sure that was unplugged. I know not where it is in the car. Never seen one before.

Your problem seems to be TPS wire related or afm wire related.

I'm not sure if this is possible or not, but I remember a guy saying he connected the TPS plug to the OMP or vice versa on some thread. Never seen a series five TPS/OMP before myself.

graniteguru

iTrader: (1)

When I plugged the TPS sensor in, the voltage at the AFM drops. The TPS seems to be the problem area. I wonder on the TPS side of the plug if those wires are correct? I am using the JDM TPS with the american harness. I don't know which color wires go on the tps side of the plug. They change colors from one side to the other of the plug/harness.

graniteguru

iTrader: (1)

Quick question. I know that the bracket is different for the TPS mount on the Turbo vs the non turbo engine, but are the sensors themselves the same?

HAILERS

I'm GUESSING the two are the same. Sorry, I don't own a series five tps or I could tell you what the colors are on the pigtail and where they go.

There's ways to figure it out by looking at the plug in the FSM.

HAILERS

In the second jpg they are looking at the wire side of the plug. In the first jpg they are looking directly into the TPS plug or the half of the plug that is attached to the TPS pigtail..

A, B, C go to the narrow range tps. That would be the one that gets it's plunger fully extended first. So find the tps that is fully extended prior to full throttle. FInd it's three wires and deternine which wire is the wiper (A). Do the Full range the same way and make the wires go where they should.

That's about as far as I care to go with this right now.

graniteguru

iTrader: (1)

I have the electrical schematic that shows the plugs and wire color positions, but sometimes it is hard to tell which side of the plug they are looking at. IN the book, I think that they are looking at the back side of the plug on the harness. The little notch on the top of the picture I am assuming is the notch that clicks into the retainer on the TPS side.

I have two TPS's from S5's and they both appear to have the wires /colors in the right position, so now I have to figure out which side I am looking at in the picture.

graniteguru

iTrader: (1)

I don't get it. The car will start and run for 2 to 3 seconds. Pressing on the accelerator has no effect. I have checked every wire back to the ecu. This is so aggravating. I am really ready to dump this thing. I have spent a year and a half restoring this car, it is painted, interior complete and now the darn thing will not run.

HAILERS

Usually a engine that will start and die a couple of seconds later, has the afm plug disconnected.
RX start up not using the afm in any way. They use a internal ECU start fuel map. After the engine reaches 500rpm the ECU starts using the afm for fuel.

Sorta what is happening to you. Try leaving that TPS plug off when you start the next time and see what happens. If it still won't stay running, go to the wiring diagrams and look at where they show the wires in the afm plug. They show that at the side of the plug where the wires enter the plug. Compare that to your afm plugs wires.

Or try jumpering that yellow, two socket fuel pump check connector and then try starting. That'll assure you the pump will keep running.

graniteguru

iTrader: (1)

Hailers,

I jumpered the fuel pump bypass and disconnected the TPS and it started and ran. Good advice. What do you think this means? The TPS is bad? I checked the readings at the tps plug last night and all seemed to be in order as far as voltages.