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CODEP0101, M1C AND M2C TEMP

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by kknguyen1168, Jan 3, 2014.

  1. kknguyen1168

    kknguyen1168 Member

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    Hi guys

    Just drove back from Houston to San diego, the trip is ok but worry so much the I got the Cold:(, I got engine light when I drove to Houston, P0101 which is MAF or VAF, I change the air filter just hope it help until I got back to San diego however did not help I had to clear out the code about 3 times, on the way back about 400 miles the engine light came back and I saw the M1C and M2C temp, the highest for M1C was 240 degree and M2C was 213 degree, I am so worry but continue to drive home, I did clear out the code 2 times on the way back, every time I clear out the code M1C temp did drop alot and stay about 203 also M2C, I noticed that M1C and M2C temp is NOT dynamic update when temp is up and stay up until you turn the car off and turn the car back on to read temp again.

    I had a couple question guys so please help me out.

    1. Should M1C and M2C temp always the same or just couple degree different?
    2. Is Code P0101 for the Air MAF senor is bad for sure?
    3. Any way can help the M1C and M2C temp cool down better? " the backseat vents always clear"

    any suggestion what should I do or check next before take to dealer

    V/r

    Khoi Nguyen

    PS: the outside temp during the way back was between 37 to 55 degree
     
    #1 kknguyen1168, Jan 3, 2014
  2. motoleon

    motoleon Junior Member

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    1.Different
    2.yes
    3.??
     
    #2 motoleon, Jan 4, 2014
  3. jdcollins5

    jdcollins5 Senior Member

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    P0101 - Mass Air Flow Circuit Range / Performance Problem
    - Mass air flow meter sub-assembly
    - Intake system
    - PCV hose connections
    - EGR valve assembly

    The above is from the 2010 DTC codes.

    Are you sure the MG temps are in C and not F? The highest I have seen mine are in the 190-200F range. MG1 usually runs about 20F higher than MG2. If yours are really in the 200 C range then they are really hot.

    What is your Inverter Coolant temperature? It has to be boiling if you are seeing 200C on the MG's. Take a look in the Inverter Coolant reservoir with the ICE running and verify that you are seeing turbulence which will mean that the coolant pump is working OK.

    What are you reading the temp data with? My SGII temp data is dynamic and updates frequently.
     
    #3 jdcollins5, Jan 4, 2014
  4. kknguyen1168

    kknguyen1168 Member

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    jdcollins5

    M1C and M2c is F temp not C, and yes the highest for M1C was 240 degree F while M2C was 213 degree F, My inverter co0lant was 203 degree F but it drop to 195 right away, I read my temp data with SGII, when you said temp data you mean the inverter coolant or M1C and M2C? yes, the coolant inverter update frequently but M1C and M2C they hold the temp only update when the temp went up but not went down.

    So 4 possible thing can be wrong, what do you thing I should change first?

    V/r

    Khoi nguyen
     
    #4 kknguyen1168, Jan 4, 2014
  5. jdcollins5

    jdcollins5 Senior Member

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    I have never seen my Inverter Coolant temp much more than 20F above ambient. My first recommendation would be to check for turbulence in the Inverter Coolant reservoir to see if the coolant pump is working. With the elevated Inverter Coolant temp I would suspect a coolant pump failure. At 203F it is close to the boiling point.
     
    #5 jdcollins5, Jan 4, 2014
  6. kknguyen1168

    kknguyen1168 Member

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    Just want to make sure the inverter coolant is in front of brake fluid container right? if it is then when the engine run I can see the coolant rotating so I do believe the inverter coolant is working.
     
    #6 kknguyen1168, Jan 4, 2014
  7. jdcollins5

    jdcollins5 Senior Member

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    You are correct about the inverter coolant location.

    Question, are you sure the inverter coolant temp that you indicate is not the ICE coolant temp? The thermostat is set for 195F and a jump to 203F is not uncommon. If by chance the reading is the ICE temp, then the MG temps are not that high.

    That would take us back to the original problem with the P0101 DTC code for the Mass Air Flow sensor.
     
    #7 jdcollins5, Jan 4, 2014
  8. kknguyen1168

    kknguyen1168 Member

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    Now I am confuse!!:(, the sign for the SGII for ICE coolant was FWT, am I correct JD? if it is then I have to go back to see how to setup for inverter coolant temp, JD, do you know what sign for inverter coolant temp for SGII?

    V/r

    Khoi nguyen
     
    #8 kknguyen1168, Jan 4, 2014
  9. kknguyen1168

    kknguyen1168 Member

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    JD

    Just check the
    Adrian Black excel sheet, I believe FWT for ICE coolant temp, and ICF for inverter coolant temp, my mistake, I just set my scangauge with ICF, FWT, M1C and M2C, will report back how the temp will be for ICF. ​

    V/r​

    Khoi nguyen​
     
    #9 kknguyen1168, Jan 5, 2014
  10. jdcollins5

    jdcollins5 Senior Member

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    I am glad you found Adian's spreadsheet. The ICE coolant fWT reading was normal. The ICF inverter coolant temp will tell you if you have a problem with the inverter coolant loop or not.

    Your MG temp readings were not abnormally high, especially if you were going up and down any steep hills.

    The P0101 DTC code and the Check Engine light go together. If you were having trouble with MG or Inverter overtemp then you should be getting the Yellow or Red Master Fault light, which you did not indicate.

    This points to the MAF sensor as being your most likely suspect.
     
    #10 jdcollins5, Jan 5, 2014
  11. kknguyen1168

    kknguyen1168 Member

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    Thanks so much for your help, for last 400 miles after I cleared out the code and it had not come back yet, I did clean out the MAF with CHOKE cleaner, if you have a BAD MAF after you clear out the code, how soon will it be come back? I just check with the dealer yesterday and it will cost about 180 for the MAF senor.

    V/r

    Khoi nguyen
     
    #11 kknguyen1168, Jan 5, 2014
  12. jdcollins5

    jdcollins5 Senior Member

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    If the MAF sensor is actually bad I would not think that it would take long for the CEL to return.

    Search on here for Patrick Wong's thread on cleaning the MAF sensor. There is a MAF sensor cleaner that is recommended. I am not sure Choke Cleaner is helping or hurting.

    If the sensor does turn out to be defective the good news is that it is easy to change
     
    #12 jdcollins5, Jan 5, 2014
  13. kknguyen1168

    kknguyen1168 Member

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    JD

    Again thanks, I will keep my eyes open to see what happen next couple hundreds miles.

    V/r

    Khoi nguyen
     
    #13 kknguyen1168, Jan 5, 2014
    jdcollins5 likes this.
  14. jdcollins5

    jdcollins5 Senior Member

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    Good luck. Keep us posted.
     
    #14 jdcollins5, Jan 5, 2014
  15. kknguyen1168

    kknguyen1168 Member

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    JD

    update, another tank of gas and 450 miles, everything seen fine after I cleaned MAF senor.

    ICF 90 degree F
    fWT 195 degree F
    M1C 175 degree F
    M2C 165 degree F

    do not know what to do now, but just bought the used MAF senor used from ebay for 32 dollars just in case. Any other advice JD?

    V/r

    Khoi nguyen
     
    #15 kknguyen1168, Jan 8, 2014
  16. jdcollins5

    jdcollins5 Senior Member

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    Khoi nguyen,

    It sounds like the Choke Cleaner did a good job of cleaning the MAF sensor. Time will tell if the CEL comes back. Good move getting the sensor on eBay.

    The temps you list are right in line with what I have been seeing.

    Good luck.

    Dwight
     
    #16 jdcollins5, Jan 8, 2014
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