need help with 92 accord trans
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Newest Of Newbies
Joined: Apr 2013
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If you checked the 12V side of the D4 light with the electrical connector unplugged, then the other side (that would lead to the bulb) should have some resistance to ground. You don't want to see infinite resistance, just the resistance of the light bulb. EDIT: Depending on your meter, you may have to go through the different ranges of the resistance to determine if the circuit is open.
All the indicator bulbs work normally except D4 (which never works). I assume from these results D4 bulb is not blown?
What next? Thanks for your help and patience!
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Newest Of Newbies
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The TCU has two connectors, one with 26 slots and one with 22 slots. I unplugged only the 26 slot one and I probed the wires just behind the connector with the red lead. The black lead I had connected to a ground point on the passenger kick panel.
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Joined: Sep 2006
Posts: 16,331
From: Houston, TX
What you were testing was the resistance of the gear position switch. You weren't testing the bulb.
10 ohms seems high to me for a open/closed circuit. What is the wire color for the D4 light coming out of the TCU?
What does your wiring diagram have for the wire color for the 12V side of these bulbs? Is the 12V side the same for all of the bulbs?
I want to make sure the wiring diagram I am looking at is the same as yours.
10 ohms seems high to me for a open/closed circuit. What is the wire color for the D4 light coming out of the TCU?
What does your wiring diagram have for the wire color for the 12V side of these bulbs? Is the 12V side the same for all of the bulbs?
I want to make sure the wiring diagram I am looking at is the same as yours.
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Newest Of Newbies
Joined: Apr 2013
Posts: 21
What you were testing was the resistance of the gear position switch. You weren't testing the bulb. as you can tell, I am a novice at this stuff.
10 ohms seems high to me for a open/closed circuit. I have a cheapie meter with a pointer, I did not zero it out before testing. It was in the Rx1 position and reads about 1.9 ohms when I touch the red and black leads together. The readings ranged around 10 to about 5, I did not realize the readings were important at this stage and thought this was going to be an on/off kind of test. What is the wire color for the D4 light coming out of the TCU? There is one labeled "D4 IND CONTROL" that goes to the light, it is GRN. A different wire goes to the gear select switch D4 position, it is GRN-BLK.
What does your wiring diagram have for the wire color for the 12V side of these bulbs? Sorry, I am not sure which side is the 12V side. My diagram shows a dimming circuit box to the left of the bulbs, the wire leads to the box and then no detail inside the box is shown. To the right of the bulbs is an arrowhead pointing away from the bulb with a vertical line at the tip (diode?). At any rate, on the diode side the colors are: D1/LT GRN-WHT, D2/GRN-YEL, D3/GRN-BLU, D4/GRN, R/GRN-RED. Is the 12V side the same for all of the bulbs? Not sure, but the diode symbols are all on the same side and pointing the same direction.
I want to make sure the wiring diagram I am looking at is the same as yours.
10 ohms seems high to me for a open/closed circuit. I have a cheapie meter with a pointer, I did not zero it out before testing. It was in the Rx1 position and reads about 1.9 ohms when I touch the red and black leads together. The readings ranged around 10 to about 5, I did not realize the readings were important at this stage and thought this was going to be an on/off kind of test. What is the wire color for the D4 light coming out of the TCU? There is one labeled "D4 IND CONTROL" that goes to the light, it is GRN. A different wire goes to the gear select switch D4 position, it is GRN-BLK.
What does your wiring diagram have for the wire color for the 12V side of these bulbs? Sorry, I am not sure which side is the 12V side. My diagram shows a dimming circuit box to the left of the bulbs, the wire leads to the box and then no detail inside the box is shown. To the right of the bulbs is an arrowhead pointing away from the bulb with a vertical line at the tip (diode?). At any rate, on the diode side the colors are: D1/LT GRN-WHT, D2/GRN-YEL, D3/GRN-BLU, D4/GRN, R/GRN-RED. Is the 12V side the same for all of the bulbs? Not sure, but the diode symbols are all on the same side and pointing the same direction.
I want to make sure the wiring diagram I am looking at is the same as yours.
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Joined: Sep 2006
Posts: 16,331
From: Houston, TX
You are doing very well for being new to electrical troubleshooting.
Now that I know you have an analog meter, that makes more sense. You can touch the leads together, adjust the needle to 0 ohm, then measure.
You can try jumping the electrical connector for the a/t gear position switch under the shifter. You would jump the grn/blk wire that goes from the TCU to the gear position switch to the black ground wire. Then see if the D4 light turns on.
With the limp mode and the behavior of the D4 light, I suspect a problem with the TCU or possibly the ECU.
Now that I know you have an analog meter, that makes more sense. You can touch the leads together, adjust the needle to 0 ohm, then measure.
You can try jumping the electrical connector for the a/t gear position switch under the shifter. You would jump the grn/blk wire that goes from the TCU to the gear position switch to the black ground wire. Then see if the D4 light turns on.
With the limp mode and the behavior of the D4 light, I suspect a problem with the TCU or possibly the ECU.
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Jumping all positions of the gear selection switch to ground individually: D4 and P did not illuminate. R, N, D3, D2 and D1 all illuminated.
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Since D4 will not illuminate when grounded at the gear select switch, I see two possibilities: 1) bulb is burned out, 2) open circuit between gear select switch and the bulb. The only way to check these two possibilities is to pull the instrument cluster?
I guess a third possibility is faulty ECU or TCU.
Got a next step for me PA?
I guess a third possibility is faulty ECU or TCU.
Got a next step for me PA?
