MoTeC Global Forum

Can anyone provide an insight into what this error message may be? (using Bosch LSU 4.2)

'Lambda Error C-6'


I have checked my wiring, and all seems fine.

The only thing I can think of, concerns the information provided on the data sheet for the LSU 4.2, version 3 software. It states under the section: "sensor setup - channel assignments - screen 1" to set "La1 Value = 9".
What does this mean?

I have all the other parameters set as required by the data sheet, including sensor setup, calibration and heater aux control.

Thanks

Tim

(C-1) - Checking Operation.
(C-2) - Control Initialization.
(C-3) - Warm Up.
(C-4) - No heater detected.
(C-5) - User Stop
(C-6) - Sensor Protection Shutdown.

A C-6 error means the ECU has gone into "sensor protection shutdown". It is unable to gain control of the sensor, and so stops trying to run current through the pump cell. This can be caused by in-correct or faulty wiring. Alternatively the sensor may be broken, or there may be a lot of carbon deposits on the sensor. You could try running the sensor in a vehicle that is running at about lambda 1 for a few minutes to see if this returns it to operation.

I just want to add clarification to this topic for anyone who may use it in the future.

I have run into some confusion with regards to these errors, and have uncovered the truth after consultation with Mark McCoy.

It appears that the table listed above of errors is for the PLM, and the M800 in fact has errors 5 and 6 switched.

So on the M800, the C-5 error is the shutdown due to error, and C-6 is the used stop.

Martin wrote:(C-1) - Checking Operation.
(C-2) - Control Initialization.

Hi,
I get many error C-1 during long trips at cruising speed with Lambda Ctrl On ( 2500/3000 rpm - around 60 kPa).
Engine is turbo, lambda is Bosch 4.9 and it's placed 70cm from turbine exhaust.
Any advice to solve it?
Thanks in advance.

I dont think this should happen....

Does it happen by itself or maybe as you tune (and maybe reset the ECU?) Does you lambda sensor stop reading while its in C1?


Do you have logging of this?

Martin wrote:I dont think this should happen....

Does it happen by itself or maybe as you tune (and maybe reset the ECU?) Does you lambda sensor stop reading while its in C1?


Do you have logging of this?

Hi Martin,
C1 Error happens by itself ONLY if I drive at steady speed under 3000 rpm in vacuum conditions ( around 65 kPa and with EGT around 720 C ) for many kms...
in fact it happened many times when I was in the highway.
Unfortunately I didn't thought about saving a log!
When it happened, lambda closed loop control was off, and, if I remember correctly, the lambda 1 value showed a fixed number... but maybe it was just the diagnostic value in case of sensor stop working...

Thanks

It would be quite interesting to see the logged data. Ive never seen this

Hi Tim,
The C6 is also shown when the Lambda sensor is setup as "Normal Heat", i.e. the Lambda sensor is not opperational is the engine is off (no RPM). Once the engine starts there is a delay time based on engine temp so it can take up to 3 mins for hte sensor to come on line if the engine is running but cold.

The C-6 was probably a convinient code to display because it realistically means the sensor has been shut down by the ECU for a specific reason where as C-5 means there is some part of the sensors reading which is completely wrong, i.e. a dead sensor.

A C-1 status (this is not an error) while driving is interesting, I wouldn't be surprised is the sensor was a bit unhappy and was shutting down. The ECU retries the sensor every 10seconds (or so) when it has gone into error, if it comes back ok it will race throught the C-3 status becasue it is already hot and probably the C-2 as well. Need the logging.

In an ECU if the sensor is dead (that is the Lambda sensing part), your wiring is wrong or your setup is incomplete/wrong you will get C-5. If the Heater circuit is broken you will get a C-4. These two errors are what you really need to worry about. And yes the PLM is a little different in that it will show a C-6 eroror if the sensor or wiring are having problems.

Hope this is a clarification.

MarkMc wrote:
A C-1 status (this is not an error) while driving is interesting, I wouldn't be surprised is the sensor was a bit unhappy and was shutting down. The ECU retries the sensor every 10seconds (or so) when it has gone into error, if it comes back ok it will race throught the C-3 status becasue it is already hot and probably the C-2 as well. Need the logging.

Martin wrote:It would be quite interesting to see the logged data. Ive never seen this

Ok, I'll make a log of it asap.

Thanks