Best way to replace ECU aka ECM Engine Control Module/Unit

[markofcain]

Acura Integra LS 2001 1.8 DOHC B18B1 Engine (non-VTEC)

Got the MIL/CEL code from Advance Auto Parts:

P0335 - Crankshaft Position Sensor Circuit Malfunction (possible causes Sensor, Circuit or ECM)
P0500 - Vehicle Speed Sensor Circuit Malfunction (possible causes Sensor, Circuit or ECM)

Since the Crankshaft Position Sensor is in the distributor, I replaced the entire distributor. Still throws both codes (P0335 and P0500). I expected to see the P0500 as I had done nothing to fix the VSS. But, since the P0335 is still being recorded, I am beginning to suspect the ECM/ECU.

My next step is to test the VSS voltage pulse at the ECM to determine the condition of the VSS and VSS circuit. If these test good, I think I am looking at replacing the ECM.

Questions:

Can I replace the ECM myself?

If I buy a used ECM, do I have to buy the ignition key as a matched set?

Where would you recommend that I buy it?

What problems might I be facing?

Thanks,

Mark Cain
Sarasota, FL USA

 

[96LSteg]

Im lost here.....before you go replacing the ECU, have you tried replacing the parts themselves? I know for a fact that the VSS does often go bad. Replace it and see if that gets rid of the code. Dont jump off of the bridge just yet, if you notice those code readings you have say POSSIBLE before ECU lol

***edit***

have you reset the ECU after replacing parts?

To answer your question, yes you can replace the ecu yourself. Its as simple as buying another one and plugging it in lol. NOTE: if you have an automatic you need an ecu for an auto LS, and so forth for the manual. No you dont need to replace any ignition or anything like that. People swap ecu's all the time. How do you think OBD2 cars tune on OBD1 ecu's lol...You could get a virgin ecu for like 150 off of phearable dot net i believe dont quote me on that. You shouldnt have any issues as long as you get the correct ecu.....

 

[markofcain]

have you tried replacing the parts themselves? I know for a fact that the VSS does often go bad.

Yes. I replaced the Distributor which contains a new CKS -- still throws the same code.

have you reset the ECU after replacing parts?

Yes. I reset the ECU by turning the ignition off and removing the 7.5 backup fuse, waiting 10 seconds per Service Manual, and replacing. The CEL did reset but came back on within the first 15 seconds.


I have a brand new VSS and will try it before the ECU.

Thank you for your help!

 

[blxxlee]

Are you sure the crankshaft position sensor is in the distributor? I think that sensor is the one by the oil pump.

 

[itzrivera]

If you do need an ECU I have an OBD 2 Auto trans ECU for sale. There are about 4 or 5 screws that hold the ECU in. Take those out and you can pull out the ECU and disconnect the plugs and boom you're done.

Let me know if you need it and good luck

 

[markofcain]

Are you sure the crankshaft position sensor is in the distributor? I think that sensor is the one by the oil pump.

Here's a print from the Service Manual. It's identified at 10 O'Clock on the page:

Click the following link: http://markcain.com/shared/acura_integra_(98-01)_service_manual_page_11-03.pdf

The text for the B18B1 engine reads:
TOP DEAD CENTER/CRANKSHAFT POSITION/CYLINDER POSITION {TDC/CKP/CYP' SENSOR (Built into the distributor)

Thanks for the reply -- but yes, I am sure that the CKP is in the distributor based on what the Service Manual says.

Mark Cain
Sarasota, FL USA
.

 

[Muckman]

On OBD2 engines there is a crank position sensor on the oil pump too. A quick google search of your error code and Im still not certain which crank position sensor is in question. Perhaps this is the issue.

 

[markofcain]

For anyone who might venture to this thread at some point in the future.

There can be a significant difference in ECUs/ECMs from year to year and even within years. I found out that you need to go by the part number on the side of the unit.

Here are a couple of photos showing the difference between two ECUs for Integra Auto Tranny:

 

[95B18BTurbo]

The crankshaft positioning sensor is down by the oil pump for one, and two the ECU is a simple plug and play with two 10mm bolts on the passenger side of the car. I'm sure you can find a another P75 for cheap just about anywhere.

 

[markofcain]

I found another ECU that is the exact part number and had it shipped across the country. I received it today and with the replacement ECU installed the engine won't start. Swap back to the old ECU and the engine runs but with the same problems as before.

When I say that the engine with the replacement ECU won't start, I mean that the engine cranks, but won't fire.

I figure that there are two possibilities:

1) the replacement which is used and sold as "pulled from a running car", arrived DOA.

or

2) there is something else that must be done to get the ECU to work

Anyone have any experience in this endeavor who can tell me what the likely issue is?

Thanks.

 

[markofcain]

So here is an update for anyone who reads this thread at a later date. Please read carefully; there IS A DIFFERENCE from year to year and some of the advice I have received on this thread is wrong b/c posters may not be aware that your model and year may not match their experience.

So to recap:

Acura Integra LS 2001 1.8 DOHC B18B1 Engine (non-VTEC) and am trying to replace the ECU/ECM.

In this year of the Acura Integra (2001) you need to have an EXACT match in part #'s when swapping the ECU.

In this model year (2001) you need to have a key that is programmed to the ECU. If you don't have the key programmed to the ECU, your 'teg will not start.

Here is how to test a swapped ECU without taking it to the dealership or having a locksmith reprogram your ECU:

If you don't have a key programmed to the ECU, call an ACURA dealership with the VIN and tell them you want the Emergency Immobilizer Start Brake Code for your particular VIN. They will give you is a 5 digit number to input into the ECU via the brake pedal. Once that immobilizer Brake Code is entered, your car will start even without a correct transponder key. If it does not start, your ECU is probably the culprit.

My replacement ECU that I had shipped across the country did not work. The EISBC did not allow the car to start. I even tried using a non-transponder key with the old ECU to confirm that the EISBC was correct -- the engine started with the old ECU but no joy with the swapped ECU.

Bottom Line:

For 2001 Acura Integra's buy an exact match part # for the ECU AND buy the transponder key that is matched to the ECU or call the dealership and test your ECU with the EISBC.

I currently an in the process of returning my non-functional ECU but I am holding onto my EISBC.

I will keep you updated and let you know how we finally get this thing fixed.

 

[HondaDNA]

This is not for you Mark, but why are so many Integra owners so vain?

The sensor on the oil pump is NOT a crank position sensor, it is the CKF (CranKshaft Fluctuation sensor) and is used to detect miss fires.

Mark did you check the circuit (wires) before jumping to ECU/ECM?


A P0335 "check engine light" code could be caused by:

Damaged CKP sensor connector
Damaged reluctor ring (missing teeth or not turning due to sheared-off keyway)
Sensor output open
Sensor output shorted to ground
Sensor output shorted to voltage
Failed crank sensor
Broken timing belt
Failed PCM