Hi guys,

I've currently got a non-starting (UK) 1997 Civic Coupe 1.6i LS. I was driving it last week when the CEL came on. As I was a couple of minutes from home, I drove back and parked up, then when I came to try the car later that day, it refused to start.

When the ignition key is turned, the car turns over but won't fire up. There is a relatively strong/blue spark at the plugs, and there is fuel in the line. At the recommendation of an RAC mechanic, I have replaced the distributor unit including leads and coil/igniter. The car still won't start.

When turning the key to ON, The CEL comes on, I can hear a relay click, the fuel pump runs for 2 seconds, and then the relay clicks again as the fuel pump stops (is this the final click, or should I hear another one?) As the fuel pump stops, the CEL goes out, but a second later it lights up again permanently.

I have tried to locate the service connector (2P) to jump and check error codes, but can't find it in the passenger side kick panel, around the ECU or under the carpet. I've heard that it may be plugged into the back of the fuse box and that you can't jump it on this model - it has to be plugged into a diagnostic box? can anyone confirm that please?

Also - please can anyone shed some light on the Honda immobiliser system? Could this be causing the problem? Does the immobiliser allow sparks to the plugs or does it just cut the injectors? I have the 'red' key for the car - should I try using that or are there serious consequences of usign the master key in the ignition, i.e. will it render the other black key useless?


Any help or advice is greatly appreciated. :)

Read the ignition troubleshooting sections in the FAQ section below:

https://www.askmehelpdesk.com/cars-trucks/automotive-repair-maintenance-troubleshooting-frequently-asked-questions-46563.html

First, run the K-Test, then focus on the main relay. Sounds like you might have a bad ECM; regardless, your problem is likely one of these two components. I am unfamiliar with the UK immobiliser and location of the Service Check Connector. I tried helping another chap locate the SCC on a UK Civic in vain. To me, common sense would suggest the immobiliser would cut power to the main relay. This might tie into my suspicion about the main relay, if the ECM checks out OK.

Hi txgreasemonkey, thanks for the very speedy reply. From reading the other topics, you certainly seem to be the man to talk to about Hondas.

Unfortunately I haven't got a multimeter or test-light so I can't perform the K-test as yet. Is it worth me taking the Main Relay out and inspecting for dry joints anyway? WOuld you advise disconnecting the battery before taking the main relay out?

Also, if the ECU is bad as you suspect - how easy is it to replace? I can see the logistics of unplugging/removal and replacement being fairly straightforward but I was wondering what the issues would be with the immobiliser - are the 2 systems coded/linked together? Would I need to get the ECU or the Immobiliser reprogrammed or recalibrated?

I'm thinking that if its just a case or unpluygging one ECU and plugging in a new one then I'll do it myself - if there's a lot more to it, then I may as well 'bite the bullet' and pay for the car to be towed to a dealer and let them sort it out.

Many thanks again for your help.

Cheers
Duncan

It's definitely worth spending a few pounds to buy a digital multimeter. You really need one, if you are going to work on cars. If need be, borrow one from someone for a few minutes to run the K-Test. It's such a very important test. Personally, I would just replace the main relay. They are so problematic, anyhow. You have a 10 year old Civic now and my experience is that it needs to be replaced. I'm not a fan of DIY bench testing or resoldering of main relays. Yes, it can be done and is done all the time. In the long run, it is not prudent for most people to follow this approach. Reliability is worth something.

Yes, always disconnect the negative. Battery cable before doing anything electrical on your car. This especially applies for removing the ECM. Replacing the ECM is very straight-forward. Undo four 10 mm nuts, disconnect the harness, and plug the new one in. However, they are expensive and it's worth investing in a DMM to verify you need one first. If the K-Test proves you need a new ECM, get the Honda Part No. off the old ECM and get an exact replacement. Then, you are sure you won't have a compatibility problem with the immobiliser.

Hi again, hopefully you'll see this message quickly as its nearly 9pm here in the UK and I haven't got much more time tonight to be working on the car.

I've finally managed to locate the service connector. For anyone else looking for it on this model...

Honda Civic Coupe 1.6i LS Service Connector Location: The connector is plugged into a blue plastic storage block on the side of the dashboard fuse box (under the steering wheel to the right. NOT in the passenger side kick panel as on other Civics from 1997/1998. The connector can be jumped to show the codes on the dash/instrument display.


I jumped the connector and the CEL flashed 4 long and one short signals (41 - Primary Oxygen Sensor - Heater)

Would this error code cause the car to refuse to start or do I still need to perform the K-test to check the ECM and Main Relay. I have bought a multimeter today but haven't located the MAP sensor yet. Help would be very much appreciated!

Thanks again
Duncan

The heated oxygen sensor won't stop the car from running. It will run on "open loop", anyway, until the engine warms up. The MAP sensor is located in the middle of the firewall. It's the sensor with a vacuum hose going to it from the throttle body. It's about 4 cm x 3 cm x 2.5 cm.

Ok great, so I should now test for 5V going to the MAP sensor. I unplug the connector to the MAP sensor and check across the Power (+) and Ground (-) sockets in the connector harness - with the battery connected and ignition turned to ON... is that right?

Thanks again for your help and advice.

Yes. Disconnect the connector to the MAP sensor, turn ignition switch to ON, attach the red (+) test lead to the right female socket of the MAP sensor connector (as you look at the opened connector), and press the black (-) test lead into the main ECM ground on the thermostat housing. Set meter to DCV.

What voltage did you record?

Ok, I think I've found the MAP sensor. It was towards the back right of the engine compartment, to the left of the battery and below the air filter box. The multimeter showed a voltage or around 0.4V. I'm just going to check the wire colourings to confirm it's the right sensor. Should I also check across the ECM pins?

It appears you have classic ECM failure. Remove your old ECM and get the exact Honda Part No. from it. I installed a Cardone remanufactured ECM, with a lifetime warranty, in my 1993 Civic DX for $253--Honda wanted $850.

Buying that multimeter just saved you a lot of aggravation and money. Most outfits charge at least a $100 just to diagnose an ECM, let alone removing and installing a new one. How easy was that? When all is said and done, you will save yourself the equivalent of $1,000.

I wouldn't waste the time running the confirming test, with readings of 0.4V. Spend the time shopping for the best deal you can get on a replacement ECM.

Well... not exactly the diagnosis I really wanted but thank you all the same for your help. The multimeter was indeed a worthy purchase and one that will get much more use no doubt. Unfortunately, I didn't have the guts to go tinkering with the electronics before replacing the distributor as initially recommended - it would have saved me some money - but I suppose it's good to know it has been changed!

With regards to swapping the ECM - are you sure the immobiliser will recognise the new ECM without having to be reprogrammed?

Thanks again.
Duncan

You can call the local Honda dealer and confirm, but I wouldn't think it would.

It's good you replaced your distributor. The sealed bearings in them normally fail anywhere from 50,000 to 90,000 miles.

Keep me posted with how everything turns out. I've enjoyed working with you.

Likewise, I've actually enjoyed the challenge of getting under the bonnet and trying to get to the bottom of the problem. For future reference for UK owners with similar ECU problems, I've found this company who test/exchange/repair/resell ECUs...

http://www.ecutesting.com

I'll keep you updated on my progress... hopefully this will be fixed in time for xmas!
Cheers again...

Looks good. The site implies the immobiliser could complicate matters--just ask around.

I'll ask them tomorrow morning. As they suggest, I may buy a free running ECU to eliminate any immobiliser problems. Obviously it will render the immobiliser obsolete but they're not exactly 100% secure these days anyway.

Cheers
Duncan

I had a 1994 Accord EX that had anti-theft equipment--I ended up removing it. To me, it's more trouble than it's worth.

Quick update. It seems no-one has a matching ECU in stock. Also, its may not be possible to reprogramme that particular ECU anyway so my only option is to test and repair the original ECU - which will take a while.

No car at Christmas then. Ah well

Did others confirm that the immobiliser would be a problem?

Yeah, I called a dealership for a quote on replacement and fitting of an ECU just to see how scandalous the prices are... £1200.00 (of which only £65.00 was labour charge). Laughable really as the car's only worth a couple of thousand at the most!

The immobiliser and ECU are linked so a straight swap without reprogramming isn't an option. A free-running ECU isn't available for the Honda anti-theft system either.

I've sent the ECU off for testing today (£35.00) which will cost £195 if it needs repairing... a slightly cheaper option!

You chose the right solution. Yes, it's unbelievable what dealers charge for replacing ECMs. You will have saved yourself a bundle and learned a lot in the process. At current exchange rates, it looks like you will save yourself around $1,910--not bad. Now, you will be in a position to minister to others with these type of problems. These are major problems in the lives of working people that affect them in a big way.

Happy New Year everyone!

OK... So I've just got the ECU back and have re-fitted it into my car... AND IT STARTS AGAIN! The only issue is that the CELight is now on continuously.

Apparently the microprocessor which had failed inside the ECU is not commercially available to buy/replace so it has been repaired - the downside is that the ECU will always throw a code even though the car runs perfectly fine... annoying, but a better option than paying £1200.00 for a new ECU.

I'm pretty happy that the car's working again so I'm just going to ignore the CEL, or take the dash out and remove the bulb.

Anyway... I just wanted to say thanks for you help greasemonkey.

Cheers
Dunc

Glad to hear your Civic starts again--I know what a thrill it is! Did the remanufacturer say that the ECM would always throw a code? If not, the CEL staying on may indicate that there is a poor or intermittent electrical connection. Check all electrical connections--clean or repair if necessary. Pay particular attention to the main ECM ground on the thermostat housing, as well as the connections going to the MAP sensor and the Throttle Position (TP) sensor. Let me know if this helps.

Duncan, do me a favor and update the K-Test Poll:

https://www.askmehelpdesk.com/cars-trucks/k-test-poll-51138.html

Yeah, I was pre-warned prior to the repair that it would always throw a code. I do know that the Oxygen Sensor needs replacing which I'll do asap.

Thanks again for your help. I'll update the K-Test Poll now.

Cheers
Duncan

Hi again!

OK... so I've still got problems with the old Civic since I got the ECU/ECM/PCM repaired. The car starts fine, but the speedometer doesn't work. It jumps around erratically from 0 to 140. The other issue is that all the lights on the vehicle continually pulse brighter and dimmer - the frequency of this increases as the revs increase.

I've located the F15 dash fuse which had blown and replaced it - but it just blows again straight away. The fuse is a 7.5A mini-blade fuse and from what I can tell from the wiring diagrams, it protects the VSS (Speed Sensor) and Alternator.

Any ideas on what I can do to resolve this issue would be greatly appreciated!

Cheers
Duncan

1. Attach a scanner and see if the ECM is throwing a code; e.g. a Vehicle Speed Sensor (VSS) code.
2. Remove 3-P connector going to the VSS and check it out. You may have a "short to ground." Access whether replacing the VSS will solve the problem.
3. Remove and thoroughly clean the main ECM ground on the thermostat housing. The VSS gound is via ECM (G101).
4. Does the odometer and trip meter work?
5. Have the alternator checked out--the short may also originate here.

It's hard for me to tell, from afar, exactly where the problem is. I am concerned it may have something to do with the ECM. Something is shorting out. Check the VSS and alternator first, then focus on the ECM.

I've finally found the main cause of the speedo issue, and have fixed it this morning. I just wanted to update this thread in case anyone else has the same problem:

If you look under the intake manifold at the rear of the engine there is a pack of wires. This pack rubs on the bottom of the intake and creates a short circuit which screws up the speedo, sets off the check engine light and gives a trouble code for the O2 sensor. And causes the headlights to surge.

Just crawl under the car when it is up on stands and gently turn over the pack of wires under the intake to expose the bare wire or wires. Tape them up with insulation tape and away you go. It's also wise to use a couple of 'zip ties' to gently pull the wires clear of the intake to prevent the problem developing again.

Hope this helps someone else in the future...

Nice job of bird dogging.