MoTeC Global Forum

Hi,
I've got a used "Like New" PLM that came with extended cables and is in very nice shape;
The problem is that upon startup it displays code C3, firmware is 1.1.2
Sensor is Bosch LSU4.9 but I suspect that something in the wiring between the Screen and the Bosch LSU4.9 Sensor isn't right...
I "calibrated" the unit using the MoTeC PLM Manager Software using the LSU4.9 Dialog but nothing changed...
Also, the Screen displays Upside Down, meaning that when the "MoTeC" Emblem is underneath the screen, the display is inverted

Thanks for your Input

That is the normal behavior I see on my PLM.
C3 means the sensor is heating. After 20-30 seconds this will go off and the current Lambda value will be displayed. If there is no active exhaust, then usually you see "--" indictating normal atmospheric oxygen content. If I blow on the sensor, or put in a propane torch flame, it will drop and indicate the Lambda value based on the oxygen content.

Do you have the PLM manual?

Appendix B in the PLM manual says this about the warmup codes:
Warm-up Codes

C-6 Sensor Protection Shutdown. The C-6 state is entered when the PLM
can not pump enough current into the pump cell to balance the sense cell.
When C-6 is entered pump current is turned off. The PLM will try to gain control
of the sensor (the C-1 state) every 10 seconds. If it is then unable to regain
control after 2 seconds then it will re-enter the C-6 state.

C-5 User Stop. The sensor has been turned off via a digital input

C-4 No Heater detected. This will occur if the sensor is disconnected or the
heater is open circuit – ie: the sensor is damaged. Heater circuit should be
approx 3ohms at room temp

C-3 Warm Up. The PLM is heating the sensor prior to normal operation and
waiting for sensor to warm up.

C-2 Control Initialization. Waiting to start pump current

C-1 Checking Operation. Waiting to get control of sensor cell voltage.

In normal operation the PLM will display C-3, C-2, C-1 then start reading lambda
values. The C-4 and C-6 error states will occur if a problem is detected.

If your display is physically upside down, I suspect someone has opened that up and reassembled it upside down. I would probably send it to your MoTeC dealer to have it assembled correctly and tested for functionality.

David Ferguson wrote:That is the normal behavior I see on my PLM.
C3 means the sensor is heating. After 20-30 seconds this will go off and the current Lambda value will be displayed. If there is no active exhaust, then usually you see "--" indictating normal atmospheric oxygen content. If I blow on the sensor, or put in a propane torch flame, it will drop and indicate the Lambda value based on the oxygen content.

Do you have the PLM manual?

Appendix B in the PLM manual says this about the warmup codes:
Warm-up Codes

C-6 Sensor Protection Shutdown. The C-6 state is entered when the PLM
can not pump enough current into the pump cell to balance the sense cell.
When C-6 is entered pump current is turned off. The PLM will try to gain control
of the sensor (the C-1 state) every 10 seconds. If it is then unable to regain
control after 2 seconds then it will re-enter the C-6 state.

C-5 User Stop. The sensor has been turned off via a digital input

C-4 No Heater detected. This will occur if the sensor is disconnected or the
heater is open circuit – ie: the sensor is damaged. Heater circuit should be
approx 3ohms at room temp

C-3 Warm Up. The PLM is heating the sensor prior to normal operation and
waiting for sensor to warm up.

C-2 Control Initialization. Waiting to start pump current

C-1 Checking Operation. Waiting to get control of sensor cell voltage.

In normal operation the PLM will display C-3, C-2, C-1 then start reading lambda
values. The C-4 and C-6 error states will occur if a problem is detected.

If your display is physically upside down, I suspect someone has opened that up and reassembled it upside down. I would probably send it to your MoTeC dealer to have it assembled correctly and tested for functionality.

Thanks for the info !
I'm sorry I forgot to add that after C3, it goes C2-C1 and then to C6-C1 and stays there !

OK, make sure your power supply has sufficient current, then try another sensor.

David Ferguson wrote:OK, make sure your power supply has sufficient current, then try another sensor.

Hi,
Tried another sensor and replaced the battery, didn't work
Please take a look at the connection diagram i posted for the pinouts between the PLM 9 Pin and the LSU4.9 and correct anything that you think is wrong, i did my research and found confusing info...
(Right Click and Open Image in New Tab if Image is Too Big)

Thank You