Car DC2 runing P28

Ok guys so this is a most odd problem I have ever encountered.

Car will turn over and with some gas pedal play I can get it to run (around 2k RPM) however the car will throw a code 5 "map sensor or circuit" and the car dies IMMEDIATELY after the car throws the code...

With the ignition switch still in the ON position I have found the following.

The resistance in the ground wires on the T-stat are around 45 Ohms.
Continuity between the battaries positive and negative terminals is present.
I have noticed the IACV is constantly huming but this is probably related rather than causing the problem?
All grounds are not only clean but I have relocated the battary to the truck, 4 awg grounding wire from battary to frame, 4 gauge from frame to block.


I think this short is causing a high amount of resistance in the grounds. I"m just wondering how to trace this because all power within the fuse box is seeing continuity to ground.

THIS ONLY HAPPENS WITH THE IGNITION IN THE ON POSITION?!?!

Thats the odd part. THERE IS NO problem in the circuit until the ignition switch is turned to the on position. With the ignition turned off the problem is no longer present and resistance in the grounds is about .5 ohms and no continuity in power to grounds...

any ideas would be great. I originally thought it was the ignition, however; after replacing the ignition switch the problem is still present.
I'm thinking the problem can be found through Ign 1 or Ing 2 wires which supply power to many other on board accessories/computers.

I've searched for similar problems but many people forget to close the their threads with the solutions and most questions are left open. Anyone ever had a common problem?

 

Ok so I just dissconnected EVERYTHING in the fuse box except the center plug. I believe the three wires in this plug lead straight to the ignition. When I tested for continuity to ground the only wire showing continuity to ground is the white wire with the black stripe...

 

Well according to the service manual the Wht/Blk wire is fused to the battary and supplies voltage to the ignition switch.

From the swtich it supplies Start, ACC, Ign 1, Ign 2...

 

Well I have spent all night and day looking at the Service manual and previous FAQs and I have learned that I may not have the proper grounding locations. I'm currenty running


I dont have the trans to chasis... So I'm going to add a few ground wires tonight and I'm also going to remove the SRS controle Module, ABS controle module and trace down the ignition wires...

What is odd about this problem is it only occurs after the car has start and been running for about 15 seconds, CEL comes on and them the problem occurs..

Also I left 4 brwn/blk wires capped coming from the driver side. Is brwn/blk wires always a ground for Acura? if so I will try supplying them to a ground also and seeing what happens (doubt this is the issue.)

 

It sounds like a sensor wire is shorted. The problem gets worse after the computer starts making use of the shorted sensor. Check the MAP sensor voltages. Keep in mind when searching that a damaged sensor could have a short on its inside rather than the wires leading to it, connecting the power to the ground.

 

Yeah I resolved that question by disconnecting the engine wiring harness as well as both the drive, injector and passanger engine harness....

 

grats?

 

grats?

whatever the problem is its occuring through three wires/circuits

ACC, IGN 1, IGN 2, START and feeding back through the battary wire through the battary and to the grounds or vise versa

 

Guys I'm really lost... I have followed the wire schematic and cant seem to track this problem!!! The ground in the power circuit is coming from Ignition 1 wire (blk/ylw). I cant seem to find what main wire is supplying this line coming out of the back of the underdash fuse box, however I have narrow it down to 1 plug C439.

The funny thing is I can remove that plug from the back side of the fuse box and expect to check continuity to ground on all wires and I dont find any, however; when I plug it back into the fuse box I recieve continuity to ground. I'm wondering if the fuse box doesnt have a short inside?

For some reason I can copy and past a page of the online shop manual so if someone could take the time its page 23-56 Ign 1 wire. I've removed all links in this circuit (fuses, drives, ect) and the problem is still present. When I'm talking about continuity to ground I'm seeing around 100 Ohms of resistance with a completly dead system (no power what so ever)

 

If you disconnect the plug and it's no longer shorted, you know that the short is on the other side of that connection. Are you removing the connection leading to the engine bay or the ECU? That black/yellow wire should run into the distributor to the ICM. It would not be unheard of for an uncovered section of that wire to be arcing to bare metal inside the dizzy. Have a look behind the ignition rotor and make sure the wires are all covered well. Unfortunately, there's not alot the forum people can do to track down a short.

 

I understand that I'm just becoming frustrated in not figure this out....

That black yellow wire does go to ICM, however; it has to get there through the engine wire harness correct? If so I have that completly Disconnected.

Also when I remove the plug on the back side of the fuse box one would imagen that you could pin each wire and figure out which one is shorting to ground. NOT not a signal one except and black wire (which I'm going to assume is a ground do to the .4 ohms of resistance) but when I plug it back up I then have short to ground on the other side on Ign 1 wire...

WEIRED

 

There are two connections to the fuse box for each wire. For example, if you pulled the plug attaching the fuse box to the motor, then there would still be wires running from the fuse box to the ECU. The same thing happens when you disconnect the ECU wires and leave the engine wires hooked up. Or another way of looking at it would be to test both sides of the connector you are removing- both the male and female ends. Unless, of course, you're saying that you get no short from either the male or female connector and then do have a short when it's connected. If that's the case, then you may only have a short when a relay is engaged.

 

thats what I'm saying, I dont have a short until I plug both those plugs up... If I remove the back side plug from the fuse box I can find any of the wires grounding out, except an actual ground wire. I will later take a picture to help eveyone understand.

If I have a bad relay which ones should I look at?

 

also to help everyone understand what is actually unhooked from the electrical circuit.

Battary positive
Both battary positive wires in the "under hood fuse box"
ALL plugs on the back side of the "under hood fuse box" except the the center plug (battary voltage to ignition)
All connections from the "under dash fuse box" exept C439 which is the center plug (6 cavities)
ECU
Engine Wiring Harness
Driver Side Wiring Harness
Passanger side harness is still intact with the main harness but there is only the radiator fan and headlights contained on this harness.

 

I'm not saying there's a bad relay. As you may know, a relay takes a low-power input signal to trigger a larger flow of electricity. If this higher current wire is shorted and the low-power signal is disconnected from the relay, it will only show continuity with the ground up to the relay. If you were to measure the relay on the side opposite the shorted side, you would find no short as long as there is no low-power signal activating the relay. Once the relay is engaged, the short can be measured on either side of the relay. Have a look at the engine bay fuse box and try to find a relay that's shorted on one side. If you find one, keep testing that side of the relay until you find the cause.

 

The only relay that power should be seen in this circuit without a fuseable link is the starter cut relay... I'll go remove it from the system and see where we stand.

 

Ok so I started unpluging one relay at a time and found that when i unplug the "power window relay" I have removed the grounding problem. This relay is contained on the "under hood fuse box" The odd thing is when I removed the relay and pin each cavity I found no short to ground (only the ground wire cavity is showing continuity which is how its supposed to be...)

So I took the relay apart and I didnt find anything abnormal, however; I dont rellay know what I'm looking for. I checked continuity between each terminal of the relay off the car and there was no continuity bettwen any two terminals...

AAHHH

 

Can you replace the power window relay with another one and see if the problem comes back?

 

No the housing is designed to accept the relay specificly....

Can a window Regulator/motor be interanly shorted and causing this?

 

remove your battery and check for cont. between the leads in all key positions. sounds like you have a bad batt.

 

No its not in the battary....

 

WTF is a "battary"? if you are not blowing fuses then you don't have a short. disconnect your fuel pump and see if your cont. between +&- goes away

 

sorry for miss spelling and sorry for calling you ignorant for not reading my thread, as i said MANY times. The problem ONLY ONLY ONLY occurs with the ignition switch in the ON position. This means that IT DOES NOT occur with the key off. and I have removed all possible causes until I found the POWER WINDOW CIRCUIT shorting out. There is a white/red wire that supplies "battery" voltage straight to the power window circuit.

So I dont have a short? is there always continuity to ground in the power supply of a circuit? interesting...

 

I will agree, I think it's the sensor itself.
You do know that if you check continuity to ground an any power lead that still has a load connected to it, it will show continuity to ground, [a short], all you are doing is "seeing" the ground on the other side of the load, EG; when the power window relay is plugged in and you test the 12V+ ign. lead to the relays coil, you will read the ground on the other side of the coil, switch meter to impedance and it will give you the resistance of that coil.
When you unplug the relay, the load, [relays coil] is no longer in line, so no continuity to ground is seen.

The same happens if you lift a ground and test it, the meter, [or test light] will indicate the 12V+ on the other side of the load, [whatever the ground is for], but that's another issue.

As I said, I agree that it is probably the sensor, no problem until you try and start the car, hard to start, a few seconds of info to the ECU/ECM from the sensor and you get a code and engine shuts down.
I would swap it out the sensor, just to eliminate it as the possible problem. 94

 

I get what you are saying. however I have never seen continuity to ground at the battary positive side in any electrical issue. I'm reading continuity withing everything unpluged EVERYTHING except the power window relay and still seeing a short circuit.

I've got a buddy with a parts car so I'm going to pic up his fuse box which contains the relays. I will figure this problem out by the end of the day