TDC Sensor

[snoopyloopy]

08 LED FLASH(s) 85-98 Accord
TDC Sensor (Top Dead Center)
defective circuit or unplugged / defective sensor

Alright gentlemen, I've decided that it's high time I get this car finished up since it hasn't been driven since July (except once when I brought it home). The title of this thread is the code I'm getting. For the longest, I wasn't even getting any codes. The engine would just be cranking with no sign of life until finally I got a CEL with that information. So now the big questions: where is the TDC sensor located and what would be some possible avenues to explore in attempting to bring it back?

[Susanoo]

TDC sensor is in the distributor, I'd say its got a dead distributor...

[Dr_Snooz]

^^ Ditto.

[snoopyloopy]

I've already tried two different ones, so I'm guessing it has something to do w/ the wiring harness. It was apparently cut and repaired w/ electrical tape, so now I know.

[Susanoo]

I've already tried two different ones, so I'm guessing it has something to do w/ the wiring harness. It was apparently cut and repaired w/ electrical tape, so now I know.

You'll have to check to make sure its all wired color to color. Theres 4 wires going to the distributor and I would recommend soldering the connections if they arent already and are wired correctly. If not pair it up correctly and then solder each connection.

EDIT: And use heat shrink tubing to cover the soldered connections. You can find it at like a Radioshack.

[ecogabriel]

TDC sensor: located lower half of distributor. See my thread for EFI distributor overhaul; there are photos of the lower chamber opened.

x2 for soldered and heat shrink the connections. The sensors can be probed with a multimeter; check the service manual for the values you should be seeing, and which color wires go to what location in the connector.

From what I have seen inside mine, it is not inconceivable a wire might have broken inside...

EDIT: Never mind I got it now! problem is in wiring: check the color wiring with the service manual anyway.

[Christofur]

i have this code on my 85 SEi i don't know how long its been there. but i have an a20 and im using my sei wiring harness. im 99.9% sure i have it hooked up right. but does anyone have a diagram. i cant seem to find the right one.

[ecogabriel]

i have this code on my 85 SEi i don't know how long its been there. but i have an a20 and im using my sei wiring harness. im 99.9% sure i have it hooked up right. but does anyone have a diagram. i cant seem to find the right one.

If your engine comes from an 88-89 you may use the USDM manual -search for it here.
If your distributor is the A20 distributor, the same manual would have the connector wiring color. But if you are using your car's own wiring harness then you have to figure out which wires connect the TDC sensor to your ECU (I am assuming you are using the 85 SE-i ECU, right?) Maybe the wires are swapped; I doubt the car would run at all otherwise since it tells when to fire the fuel injectors

[snoopyloopy]

TDC sensor: located lower half of distributor. See my thread for EFI distributor overhaul; there are photos of the lower chamber opened.

x2 for soldered and heat shrink the connections. The sensors can be probed with a multimeter; check the service manual for the values you should be seeing, and which color wires go to what location in the connector.

From what I have seen inside mine, it is not inconceivable a wire might have broken inside...

EDIT: Never mind I got it now! problem is in wiring: check the color wiring with the service manual anyway.

Yea so I've checked the wiring and the wires that had originally appeared to be the ones that had been repaired in the past were actually for one of the temp sensors. not TDC. TDC wiring is still fine so I figured that cutting into the harness more would do more harm than good. All the wires look good, not visibly damaged, yet I still keep getting the same TDC code. Only other thing I can think of is to go grab a harness from the jy (assuming I can find one unmolested and see if it works. Anyone else have any other ideas, do share. I've done it enough times to know that swapping harnesses is a pain.

[ecogabriel]

Did you check the sensor itself? The service manual tells you which wires in the plug are for what sensor, and the values you should see when testing with a multimeter.

I am not sure whether those sensors may go bad, but it would not be a bad idea to test the sensor BEFORE tinkering with the wiring.

[Dr_Snooz]

There is actually a diagnostic troubleshooting procedure in the manual. The CEL indicates a problem in the TDC circuit. You have to perform the troubleshooting procedure to find out what exactly is failing.