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  #31  
Old 02-17-2015, 05:28 PM
josh_s13 josh_s13 is offline
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See page 165 for resistance checking on the knock sensor. Check in from the white wire on ecu pin 27 with the ecu unplugged ( measure on the harness side of the connector) vs directly at the knock sensor. This will check the wiring and the sensor together. This may increase the odds of misdiagnoses, but eliminates the dissambly required.
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  #32  
Old 02-17-2015, 06:02 PM
zack11122 zack11122 is offline
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Hm. I'm gunna go through and re do my readings when it's warmer. I'm not sure what's up. But my harness is un touched


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  #33  
Old 02-19-2015, 01:06 PM
zack11122 zack11122 is offline
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Haven't gotten to resistance checking but I did check voltage. White wire was at 12 volts. Black was at 12.8 volts. Black/white was at 14 volts. All tests were performed on a warm motor. Engine running. Black lead on the negative terminal. Cleaned the maf with maf cleaner. Same results.


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  #34  
Old 02-19-2015, 03:13 PM
zack11122 zack11122 is offline
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So I did some digging around. Ran a new ground for the maf and now the white wire runs about 4 volts now. Grounds resistance is about .1-.5


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  #35  
Old 02-20-2015, 05:53 AM
josh_s13 josh_s13 is offline
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From looking at the FSM the only thing on the MAF that should be grounded directly is the shielding on the harness. Which wire did you take to ground?
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  #36  
Old 02-20-2015, 06:18 AM
zack11122 zack11122 is offline
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The black ground wire. Looked around on google and some people have had that ground being the problem.


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  #37  
Old 02-20-2015, 06:42 AM
josh_s13 josh_s13 is offline
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I don't think that's a good idea. If that's what it takes to fix it, you still ave a problem. Unless you (or anyone else around here) understand the internal architecture of your ECU, grounding that black wire is like applying a risky bandaid to the problem. You could be bypassing internal circuits. I.E. the ECU may measure voltage drop on the negative leg of the MAF to determine fuel metering. IF that was how the ECU was designed, then grounding that leg would drop the ECU's "seen" voltage drop to near zero.
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  #38  
Old 02-20-2015, 07:48 AM
Def Def is online now
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Sensor ground must go back to the ECU.

I think you might have fried something by putting your meter from a 12V+ leg across the MAF and potentially the ECU circuit.

Isn't the MAF on a 5V circuit? I know its max output is 5V.
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  #39  
Old 02-20-2015, 08:49 AM
Z28ricer Z28ricer is online now
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Power feed to the maf is 12v

Output signal is 5v max
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  #40  
Old 02-20-2015, 09:20 AM
zack11122 zack11122 is offline
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Hope I didn't fry anything. I'll hook it back up and see where it goes from there I guess.


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