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coconutmilk · Dec 3, 2012, 02:42 AM

Originally Posted by TxGreaseMonkey

41 = Primary oxygen sensor heater

Here's how to replace the oxygen sensor:

https://www.askmehelpdesk.com/cars-t...tml#post223376

Hi, TxGreaseMonkey,

I came to this site because I also have a "Check Engine" light on my Honda Civic. Before I start a new thread addressing my problem, may I ask you about this particular comment of yours to Jacob77.

When I check your hyperlink, it's about "25. Honda Oxygen Sensor Replacement"

I also checked the rest of the linked webpage and searched for "primary oxygen sensor heater" but found nothing.

Could you please help me?

Thanks.

ma0641 · Dec 3, 2012, 06:53 AM

There are 2 O2 sensors on the Honda, primary and secondary.

TxGreaseMonkey · Dec 3, 2012, 07:32 AM

When there's a DTC that indicates that there's a "Primary Oxygen Sensor Heater" problem, the solution invariably requires replacing the "upstream" sensor. Hence, the hyperlink on how to replace it.

coconutmilk · Dec 3, 2012, 09:06 AM

Dear ma0641 and TxGreaseMonkey,

Thank you for your replies to my question.

I'm perhaps missing something. But what I don't understand is how you went from
"4 short, 1 long" set of flashes" to "Primary Oxygen Sensor Heater" problem.

In other words, how did you know that " problem.

In other words, how did you know that " = "Primary Oxygen Sensor Heater" problem?

Thanks again.

TxGreaseMonkey · Dec 3, 2012, 09:43 AM

Here is Jacob77's original quote:

I counted the number of flashes from the "Check Engine Light" -- four long, one short.

That's a DTC 41, Primary Oxygen Sensor Heater.

ma0641 · Dec 3, 2012, 09:44 AM

Originally Posted by coconutmilk

Dear ma0641 and TxGreaseMonkey,

Thank you for your replies to my question.

I'm perhaps missing something. But what I don't understand is how you went from
"4 short, 1 long" set of flashes" to "Primary Oxygen Sensor Heater" problem.

In other words, how did you know that "4 short, 1 long" = "Primary Oxygen Sensor Heater" problem?

Thanks again.

That is the code the check engine light gives. It does not spell out the problem, it flashes a code which is then translated by book or OBD tester.

coconutmilk · Dec 3, 2012, 09:50 AM

ma0641,
Thanks for your reply.

Is this list of codes available online?

coconutmilk · Dec 3, 2012, 10:53 AM

Never mind. I found the list on The Codes Thread: How To Pull CEL, D4, SRS, and ABS Codes (with Code Lists) - Honda-Tech

Thanks.

coconutmilk · Dec 3, 2012, 11:20 AM

Dear AskMe community,

I have a 1995 automatic Civic. After doing some maintenance work on the Civic (replacing distribution cap and rotor; checking transaxle/transmission fluid; checking brake fluid level, adding coolant; cleaning battery terminals and battery clamps) the car now gives a "Check Engine" light when the car is running.

We didn't think we did any damage to the engine, so we thought maybe we just have to disconnect the battery temporarily, and turn ignition to II ("2") to remove any remaining electrical power and then reconnecting the battery. That didn't help.

I then tried to get the Engine Code by putting either end of a metal paper clip into a thingy on the right side of the front passenger seat. Below the glove box.

Here's a pic

I then turned the car key in the ignition to II ("2"), but I did not get any flashes at all.

Please help. I really want to know why I'm getting the "Check Engine" Light.

Thanks.

coconutmilk · Dec 3, 2012, 11:22 AM

Dear ma0641 and TxGreasemonkey,

I created my own post with my own problem at
https://www.askmehelpdesk.com/cars-t...es-720531.html

Please take a look. Thank you so much.

TxGreaseMonkey · Dec 3, 2012, 12:49 PM

When you turn the ignition switch to ON (Position II), does the Check Engine Light (CEL) come on and then go off after 2 seconds? If not, the problem is with the ACG (ALT) (S) fuse, in the under dash fuse/relay box; ECM (perform the K-Test, below); main relay; or the ignition switch.

The K-Test: Remove the MAP Sensor connector and turn the ignition switch to ON (Position II). Using a multimeter, check for 5 volts going between the MAP Sensor connector's reference wire (+) and ground. As you look at the connector, this is the socket on the right. Really press the black test lead into a cleaned main ECM ground on the thermostat housing. If the voltage is low, it's probably indicating ECM failure. Most failed ECMs will record a fraction of a volt.

I suspect ECM failure, which is common on these older Civics. You will likely need to remove the old ECM, get the Honda Part No. and buy a remanufactured ECM (shop for price and warranty).

coconutmilk · Dec 3, 2012, 01:09 PM

Hello, TxGreaseMonkey,

When I turn the ignition switch to On, Position II, yes, the Check Engine Light comes on and then goes off after 2 seconds.

I did this without any paper clip in the blue plastic thingy.

TxGreaseMonkey · Dec 3, 2012, 01:25 PM

If a code is thrown, the CEL will stay on. It sounds like your CEL is not staying on, however. Hence, no code was stored in the ECM.

coconutmilk · Dec 3, 2012, 01:32 PM

TxGreaseMonkey,
I figured out what I was doing wrong. I was not inserting my paperclip the right way. When I moved the paper clip tips to the other side of that metal barrier in the middle, then I got some blinking.

And here's how it blinked: 9 short, 0 long, then pause (no CEL light) for about 2 or 3 seconds. Then this would repeat. According to The Codes Thread: How To Pull CEL, D4, SRS, and ABS Codes (with Code Lists) - Honda-Tech, "9-0" means "Evaporative Emission Control System Leak". How do I fix this?

Thank you.

TxGreaseMonkey · Dec 3, 2012, 01:47 PM

90--Evaporative Emission Control System leak detected in the fuel tank area.

Ensure the gas cap is tight and not leaking.

coconutmilk · Dec 3, 2012, 01:56 PM

Originally Posted by TxGreaseMonkey

90--Evaporative Emission Control System leak detected in the fuel tank area.

Ensure the gas cap is tight and not leaking.

Hi, TxGreaseMonkey.
Thanks for your reply.
I pulled the lever for the fuel "mini-door" and tightened the gas cap until it clicked about 10-15 times. Then I started the car (position III) again. But I still see the CEL light. :-( Does this mean there's still some other problem?

:-(

TxGreaseMonkey · Dec 3, 2012, 02:06 PM

Disconnect the negative battery cable, or pull the 7.5A Backup Fuse in the under hood fuse box, for 10 seconds and that will clear the code. Then, see if the code returns.

coconutmilk · Dec 3, 2012, 02:08 PM

TxGM,

1995 Civic shows "Check Engine" light. I put paper clip into 2 holes but no flashes - HondaCivicForum.com

says that the problem probably is with CYP (distribution/rotor) and not Gas Cap. The poster's conclusion fits well with the maintenance work that my friend performed on my Civic.

I've asked him how he determined that 9 short , 0 long flashes = CYP and not EVAP.

If you know, please advise.

:-)

TxGreaseMonkey · Dec 3, 2012, 02:19 PM

Codes 1 through 9 are indicated by individual short blinks. Codes 10 and above are indicated by a series of long and short blinks. The number of long blinks equals the first digit; the number of short blinks equals the second digit. Therefore, I think you have a Code 9 = CYP--Cylinder Position Sensor.

The CYP is an unserviceable sensor, located in the distributor. You need to buy a new genuine Honda distributor housing and install your current Ignition Control Module (ICM) and coil in it. Be sure to apply silicone heat transfer compound to the back of the old ICM. Don't waste your time or money installing an aftermarket distributor, which are junk and unreliable.

coconutmilk · Dec 3, 2012, 02:19 PM

[QUOTE=coconutmilk;3338782]TxGM,

I just talked to my friend who replaced my Civic's distributor cap and rotor and he admitted using much force. He thinks he did break some plastic part that was acting as a shield. :-(

He'll be coming by in 10 minutes.

:-(