Inclination sensor JN
20
11 DTC – Diagnostic Trouble Codes
When the diagnostic function is activated via the index 0x800h/01h, the following
DTC messages are sent every second.
SPN
(19-bit)
FMI
(5-bit)
CM
(1-bit)
OC
(7-bit)
Meaning of the message
DM1
DTC1
521001
4
0
-
undervoltage
DTC2
521001
3
0
-
overvoltage
DTC3
521002
1
0
-
internal ambient temperature too low
DTC4
521002
0
0
-
internal ambient temperature too high
DTC5
521003
1
0
-
MEMS temperature too low
DTC6
521003
0
0
-
MEMS temperature too high
DTC7
522001
10
0
0x01
timeout of a transmit message
DTC8
522002
10
0
0x01
timeout CAN interruption
DTC9
522003
10
0
0x01
timeout of a receive message
(SPN – Suspected Parameter Number; FMI – Failure Mode Identifier; CM – SPN
Conversion Method; OC – Occurrence Count)
Diagnostic trouble codes are always transmitted as a 4-byte value.
This 4-byte DM1 message is to be interpreted as follows:
DTC
Byte 1
8 least significant bits of the SPN
Bit 8 is MSB
Byte 2
Bit 8 is MSB
SPN
3
1
3
0
2
9
2
8
2
7
2
6
2
5
2
4
2
3
2
2
2
1
2
0
1
9
1
8
1
7
1
6
DTC
Byte 3
3 MSB of the SPN
5 bits of the FMI
Byte 4
SPN
FMI
CM
OC
1
5
1
4
1
3
1
2
1
1
1
0
9
8
7
6
5
4
3
2
1
0
Example showing the undervoltage detection (< 9.2 V)
FF FF 29 F3 E4 01
16-bit global lamp status (deactivated) -> FFh
19-bit SPN -> 7F329h -> 521001d