Malibu response 2003

[Doin]

Hi I'm looking for some information there's been a quite a few posts about this but I still can't seem to fix it. 2003 Malibu response with a monsoon engine I keep getting the warning beep. Seems to only occur at higher RPMs. I replaced the oil pressure sending unit and pressure switch. Also replaced the knock sensor. Anybody have any ideas where to go next? Can't seem to find any type of information wiring schematics etc on this topic past what I've already done. 

Any help will be greatly appreciated

[Woodski]

What are the gauge readings? Oil pressure and water temperature.  Look on the water side also, clear any debris in the water separator, trans cooler.

[csleaver]

Have you checked the ECM for fault codes?

[Steve B.]

Curious when the last full tune-up was. I'm wondering if the knock sensor is being needed too much? How's the gas quality, high ethanol?

Steve B.

[Doin]

All the gauge readings are good oil pressure is where it's been since I bought the boat water temperature right about the same as it's always been. 

I haven't checked the ECM codes How do you do that on this boat? Do you have to have a scan tool or can you use a grounding pin method? It doesn't really have a light to flash so I guess it would have to be from the buzzer. I've always burned premium fuel same fuel as always never really hear any detonation sounds. So if there's a code set in the ECM it sets this buzzer off as well? 

[Doin]

Last tune-up was last year and it runs amazing

[csleaver]

I use Rinda Diacom and think it is the best way to do ECM diagnostics.  That is just my opinion and there are several other methods. 

[SkiPablo]

i have used the paperclip and led light method to scan for codes - if your interested I can dig up that info.

honestly it sounds like an overheating beep if I was to give it my first guest - have you checked your transmission cooler for debris and have you checked the raw water impeller?

[Doin]

7 hours ago, SkiPablo said:

i have used the paperclip and led light method to scan for codes - if your interested I can dig up that info.

honestly it sounds like an overheating beep if I was to give it my first guest - have you checked your transmission cooler for debris and have you checked the raw water impeller?

Yeah that'd be great You could pass on the information on how you check for codes I really appreciate it. I don't think it's overheating temperature gauge is rock hard solid. With strange is I could run all day long under 3000 RPM and it will never come on. Raw water pump impeller was replaced last year. And she's never really overheated

[csleaver]

The sensors monitored by the ECM use voltages from 0.1 to 4.9 VDC and must be within a certain programmed parameter window or a DTC fault can occur.  A physical running issue does not necessarily need to happen for a DTC to occur, an electrical problem may also cause one.  There are 21 different DTC codes that may occur from DTC 13 to DTC 81 and some have multiple variables.

Here is a link to a MEFI4 service manual that goes into more diagnostics testing procedure details and what tools and equipment are needed to perform them.

https://www.m2omarine.com/fckimages/pdf/INDMAR-service/03.pdf

 

[SkiPablo]

On 9/12/2022 at 2:53 PM, Doin said:

Yeah that'd be great You could pass on the information on how you check for codes I really appreciate it. I don't think it's overheating temperature gauge is rock hard solid. With strange is I could run all day long under 3000 RPM and it will never come on. Raw water pump impeller was replaced last year. And she's never really overheated

this is how i made my reader - just be careful to get the right pins - https://www.offshoreonly.com/forums/do-yourself-boating-budget/103342-make-marine-efi-code-tool-less-than-%241-00-a.html

i have extra leds if you need some or you can pick them up online for cheap.

Edited September 13, 2022 by SkiPablo

[Doin]

Thanks for all the info Good stuff I made a code reader and then was able to pull codes. Have a code 44 which is a knock sensor. I replaced the knock sensor already I still get the code set. Connector and terminal look clean and I ran a draw test on the terminal and that seems good too. Does the DTC need to be cleared after the repair? If so do you know how to clear the codes?  Is there a way to check the ECM output for the knock sensor? Does it supply a voltage of some sort? 

[tvano]

iirc the codes will clear after ~3 run (hot/cold) cycles

[BillFooter]

I have a 2000 Response and when it was new I was getting a warning beeper only at high speeds.  It's been a long time ago, but if I remember correctly it was the transmission temp sensor.  I think we tested it by jumping the plug with a paperclip, and the beeper would stay off.  I replaced the sensor/sending unit and that fixed it.

[Doin]

Now I'm really confused. I pulled codes has a code 44. I tested continuity between the ECM pin and ground. 3.8 k. Same reading with the new knock sensor and the old sensor. When I switch to AC scale measure the voltage and tap around the engine block I get output voltage. If I tap fast enough I can get about 1.0 v. So this test is telling me the wire is okay the terminal and connector's okay and I'm assuming the sensor's okay yet I still get a code 44 and a buzzer at high RPM. The  3.8 k on both sensors the new one and the original one does not match what I read the range should be. I find it hard to believe that both sensors would have the same resistance value unless when they go bad they would have a common resistance value. From what I read the range should be 80K 110 k. Any comments would be appreciated and advice as to what to do from here. Lol I'm about ready to cut the buzzer

[justgary]

Do you have a knock sensor on each side of the block?

[Doin]

No only one

[csleaver]

Make sure your knock sensor wire is not too close to the ignition wires and that the ignition wires are in good condition to avoid voltage induction to the knock sensor wire.

[Doin]

15 hours ago, csleaver said:

Make sure your knock sensor wire is not too close to the ignition wires and that the ignition wires are in good condition to avoid voltage induction to the knock sensor wire.

Yep I checked that Thanks for reminding me. No wires are touching. 

[electricjohn]

I will check my resistance today if I can get under the clamshell. Currently winterizing, and it's rainy.

[Doin]

20 hours ago, electricjohn said:

I will check my resistance today if I can get under the clamshell. Currently winterizing, and it's rainy.

That would be great I really appreciate it.

[Murphys]

I had an issue with the beeping with no message displayed on the gauge earlier this year. The only way to clear the mystery alarm was to shut the engine off and restart.  I replaced both batteries for the boat and have not experienced the beeping issue since. Batteries were nine years old.

If I ever have the issue again, I will use techniques listed in this thread to properly diagnose the beeping source.

[electricjohn]

3 hours ago, Doin said:

That would be great I really appreciate it.

Measured 3900 ohms with sensor removed.

[Doin]

Great thanks That's what I got on mine too. Strange it doesn't agree with what the book says. But I'm assuming it's right two sensors I have are reading 3900 and now your validating that yours does too.

[electricjohn]

On 9/21/2022 at 10:15 AM, Doin said:

Great thanks That's what I got on mine too. Strange it doesn't agree with what the book says. But I'm assuming it's right two sensors I have are reading 3900 and now your validating that yours does too.

Although you are seeing a 1 volt output during a simulated knock, the signal the ECM is looking for is a 1 Kilohertz pulse.