I'm looking for some answers about my code 8 TDC fault.

My ck eng light was on, had the codes read @ Autozone, 3 faults (P0171 fuel trim bank 1, p402 Cat efficiency low bank 1, p401 EGR valve sys fault). Cleaned o2 sen, reset codes, ck eng lt back on. Had codes read at Advanced Auto, only EGR valve insufficant flow now. Cleaned EGR valve, reset codes, ck eng lt back on, had codes read, still faulting EGR vlv. Bought new vlv and installed, ck eng lt back on.

I followed my Hanes book and read the codes myself, I get code 8 -TDS sensor. But the auto part store reads it as EGR vlv(p401), why is there a differance in the codes?

Do I need a TDC sensor or look at changing the EGR soleniod?

I have also researched TDC sensor and have found that it is the same thing as a crank position sensor and is located under the timing chain cover(lwr half). Is this info correct?


I would like to know which sensor is bad before I dump another $100.00 on the wrong sensor. Can anyone give me some direction on which one is bad and how to ck? Thanks,

Skuffknee Lee

Car is a 96 accord LX, 4 cyl, 263,000 m, auto

 

Be careful researching for what year. 1996-98 is about the time when Honda was moving some of those sensors around from inside the distributor to down at the crank.

I don't know why the OBD-1 code (jumper & flashing light) would be different from the OBD-2 code (from scanner).

You can check each sensor with an ohm-meter, but that's not as conclusive as using an oscilloscope. Or an OBD-2 scanner which can display live data.

 

The TDC sensor is not available as a part. It's in the distributor in 94 Accord manual and I think 94-97 are all the same.

I had this code occur once due to my improper installation of the distributor into the camshaft keyway. When i tightened the bolts I bent an internal frame cause sensor misalignment and code error. I remove distributor and was able to straighten the frame.

A new (aftermarket) or used distributor can be purchased very reasonably. I would go w/ a used as they will be much cheaper. Check ebay or car-part.com for one near your zipcode.

If you got the codes right, Autozone misread them. P0420 is catalytic converter efficiency problem, not P0402. Code 8 (Obd1) corresponds to three OBD2 codes (P1359, P1361, P1362). All are electrical faults in the TDC sensor circuit. Might be worth getting a 2nd opinion on the OBD2 codes. If you have a TDC sensor fault the OBD2 code will narrow the type of fault down; disconnected, intermittent, or no TDC signal.

good luck

 

I had it read at Auozone and Advanced Auto; both said the same thing. I have the print out from Autozone here now. P0401 - PCM determend that there is insufficient flow in the EGR system.

I'm pretty sure that I read on another forum that in '96 the TDC sensor/crank sensor was not on the distributor (but hope that it is).

 

Read your post and mine. I wasn't questioning P0401, but P0402.

good luck