Medium and Heavy Trucks
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The ECM has not detected the size of the DPF. The ECM is using the default size for the DPF. The power rating of the engine determines the default size. Engine power is derated. One of the following diagnostic codes is present:
3936-2 The signal indicates that the size of the DPF is not correct for the engine's power rating.3936-3 The signal from the sensor group is above the acceptable limit.3936-4 The signal from the sensor group is below the acceptable limit.Once the system is powered via the keyswitch a delay of approximately 15 seconds will occur before the code appears.
Greater than 100 hoursOrEqual to 100 hoursThe ECM has not detected the size of the DPF. The ECM is using the default size for the DPF. There is no 3936-x diagnostic code. There is no derate.Flashing software that has a personality module release date that is newer than OCT 07 can cause the condition. No troubleshooting is required.
XXXX********** (1) N/A The ECM has automatically detected the size of the DPF. There is no 3936-x diagnostic code. There is no derate. No troubleshooting is required.
XXXX1234567890 (1) N/A The serial number of the DPF has been manually entered into the ECM. There is no 3936-x diagnostic code. No troubleshooting is required.
Test Step 1. Program the Serial Number for the DPF into the Engine ECM
Note: The serial number typically has 14 characters. If the serial number contains less than 14 characters enter zeroes to the end of the serial number in order to complete the programming.
The 3936-x code is cleared.
Repair: Perform the following procedure.
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