The other common failure is the DC to DC converter but randomly throwing parts at it without codes etc is a bad idea. Take it to the dealer and have them read the codes and diagnose it. Or take to any car parts place and they will read the codes for free. Since you have the FSM that will guide you. At least it is triggering the light that indicates there are codes if you have not cleared them by disconnecting the battery. Do not disconnect the battery to "fix" it. Have it diagnosed.
IMA issues, fuse 53 blowing, troubleshooting
OK, so my son has a 2011 CRZ with 85K on it. The IMA warning light keeps coming on, likely after it blows the fuse 53...multiple times. Sometimes I can drive the CRZ 50 miles before it blows the fuse...sometimes not even a mile. I went through all of Honda's diagnostic tests in the manual. The blow fan gets 12 volts and feeds back 5v. According to Honda diagnostics, the IMA battery fan is good. Just to verify, I bought a used IMA fan and it does the same thing. Sometimes I can hear the fan, but shortly after, it stops and IMA warning lights and charging lights come on. I have checked the 2 IMA relays and they are also working and good. The 12v starter battery is only 1-1/2 years old. It is a Honda OEM and it charges to 13+ volts fine and I had it load tested just to make sure it wasn't having that kind of issue and it is fine. Obviously, when the IMA lights come on, it no longer is being charged by the inverter so it starts to lose its charge. I am at a loss of what to do other than to change out the MCM blower fan control unit. Anyone have any other ideas?? If I do replace with a new or used MCM ($100 used, $200 new) does anyone know if it will need to be reprogrammed or have a software update by a Honda dealership, or should it work fine as-is?
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Yes, I disconnected the battery a few times... I bought the fan before I found the Honda diagnostic manual, otherwise I would have seen that my fan was good and I would not have bought that part. I went through the entire Honda FSM diagnostic...the only thing I didn't do was swap out the MCM with a known working one, as it suggests.
The error code only reads P1448....that doesn't get you anywhere except to know it is on the IMA fan circuit....auto stores code reader is generic, not Honda Specific, and gives the code P1448 so it doesn't help. I just found a $25 MCM used module...that is much less than Honda diagnosing that I need to replace it. Do you happen to know if it the MCM needs to be reprogramed if it comes new, or from a different CRZ??. But you are likely right, other thing may be DC inverter. Hope that isn't it, but after I swap out the MCM and if that doesn't cure it, I will take it into Honda.
The error code only reads P1448....that doesn't get you anywhere except to know it is on the IMA fan circuit....auto stores code reader is generic, not Honda Specific, and gives the code P1448 so it doesn't help. I just found a $25 MCM used module...that is much less than Honda diagnosing that I need to replace it. Do you happen to know if it the MCM needs to be reprogramed if it comes new, or from a different CRZ??. But you are likely right, other thing may be DC inverter. Hope that isn't it, but after I swap out the MCM and if that doesn't cure it, I will take it into Honda.
No programming should be needed. If it is working then at this point I am sorry to say since it has the code the dealers may have more details than the FSM( but shouldn't), there is obviously an issue. Make sure the part number on your replacement is the same as the one you remove but I think the same part number covers all years. When you say MCM do you mean the IPU fan? Clean the fan if there is any dust or dirt in it. Dealer should be able to read the RPM on the fan and run a fan diagnostic.
I have had mine tested a few times since I never hear my IMA fans for the last few years used to hear it the first few years I owned the car. Now I do not but I have not gotten an IMA light either.
I wish people would stop disconnecting the battery and clearing the codes that does nothing other than delay having the same codes pop up and forces the car to relearn some parameters. Same with using a code clearing device.
I have had mine tested a few times since I never hear my IMA fans for the last few years used to hear it the first few years I owned the car. Now I do not but I have not gotten an IMA light either.
I wish people would stop disconnecting the battery and clearing the codes that does nothing other than delay having the same codes pop up and forces the car to relearn some parameters. Same with using a code clearing device.
Had to take out 12v battery to charge, since charging stopped working. It was not to clear codes...but I already know the code... P1448 that is all that comes up.
The MCM is the motor control unit that controls the IPU fan and other things. It sits right on top of the hybrid battery. Very common problem and stated all over this forum. It is what the Honda FSM states to swap out if all of the other diagnostics come back okay, including the IPU fan (which I already swapped out with a used $50 IPU)
Don't believe the MCM is the same in all CRZ's. I have a 2011. I think the 2011 and 2012 are different than the 2013 to 2015. Yes, I am sure the $25 part is from the same year, same part number...amazingly it is being sold at a used part store 5 miles from me....same VIN number, except for the last 4 digits.
The MCM is the motor control unit that controls the IPU fan and other things. It sits right on top of the hybrid battery. Very common problem and stated all over this forum. It is what the Honda FSM states to swap out if all of the other diagnostics come back okay, including the IPU fan (which I already swapped out with a used $50 IPU)
Don't believe the MCM is the same in all CRZ's. I have a 2011. I think the 2011 and 2012 are different than the 2013 to 2015. Yes, I am sure the $25 part is from the same year, same part number...amazingly it is being sold at a used part store 5 miles from me....same VIN number, except for the last 4 digits.
I never said the MCM was the same part number only the fan. MCM is going to vary due to different IMA system and ECUs in the different years.
If the IPU fan did not fix the issue and not knowing what the cost is of a replacement MCM if it were me I would have a dealer diagnose and state that if they swap the MCM ( you maybe able to get a used one from here Used CRZ Parts | Honda | 2011-2016 | Redline Auto Parts) and it does not resolve the issue you are not paying for it only their labor.
If they have the fan from the same year with a close VIN maybe the have an MCM?
If the IPU fan did not fix the issue and not knowing what the cost is of a replacement MCM if it were me I would have a dealer diagnose and state that if they swap the MCM ( you maybe able to get a used one from here Used CRZ Parts | Honda | 2011-2016 | Redline Auto Parts) and it does not resolve the issue you are not paying for it only their labor.
If they have the fan from the same year with a close VIN maybe the have an MCM?
Had to take out 12v battery to charge, since charging stopped working. It was not to clear codes...but I already know the code... P1448 that is all that comes up.
The MCM is the motor control unit that controls the IPU fan and other things. It sits right on top of the hybrid battery. Very common problem and stated all over this forum. It is what the Honda FSM states to swap out if all of the other diagnostics come back okay, including the IPU fan (which I already swapped out with a used $50 IPU)
I have been talking about the MCM, not the IPU fan. As I have also stated, I swapped out the IPU fan already...obviously it has to be the same part number to swap out and fit, and have the harness cable connect to it. I am surprised you do not seem to know of the MCM as the Super Moderator. Like I said, the used MCM for $25 is from the same year CRZ as I have...same part number...it is the exact part. Why would I go to Honda, pay them $130 or more to "diagnose" when I can swap out the exact part for $25 myself??? Why would I go to a Used CRZ Parts store when it is sitting 5 miles from me from a same year CRZ??? To replace it is easy to do. Just remove the bolts over the battery cover and the MCM is right there. Part of the Honda diagnostics for the IPU fan was to check the wiring from the MCM to the IPU so I already have had the cover off.
I misunderstood you. No reason to get angry at me. I try to give very general advice to help persons all over the world. If they have it and it is the same part number go for it. I always try to tell anyone who is swapping parts to make sure it is the same part number. There are too many possible variations for most electrical parts and most are not returnable. Basic precautions.
I am a super moderator for one reason only there was an issue where members could not edit their posts. I could not edit mine , I complained and they made me a Super Moderator so I can help out. I am just an owner like many of the members here.
I am a super moderator for one reason only there was an issue where members could not edit their posts. I could not edit mine , I complained and they made me a Super Moderator so I can help out. I am just an owner like many of the members here.
We are having the same issue. Same code. We first checked fuses and had a blown fuse. But after about 50 or so miles it blows the fuse again. I’m searching for a MCM and I’m only finding ECM is that the same part? 37820-RNA-A73?I never said the MCM was the same part number only the fan. MCM is going to vary due to different IMA system and ECUs in the different years. If the IPU fan did not fix the issue and not knowing what the cost is of a replacement MCM if it were me I would have a dealer diagnose and state that if they swap the MCM ( you maybe able to get a used one from here Used CRZ Parts | Honda | 2011-2016 | Redline Auto Parts) and it does not resolve the issue you are not paying for it only their labor. If they have the fan from the same year with a close VIN maybe the have an MCM?
And our stealership wants to charge $450 just to diagnoseWe are having the same issue. Same code. We first checked fuses and had a blown fuse. But after about 50 or so miles it blows the fuse again. I’m searching for a MCM and I’m only finding ECM is that the same part? 37820-RNA-A73?
If you have a P1448 code you need a new IMA fan.
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