Fault-Tracing
Fault-tracing
Checking the software
Note! Stored diagnostic trouble code indicates that a malfunction has occurred in the control module's software. Depending on in which part of the software that the malfunction has occurred, reprogramming may solve the problem.
- Download the latest software in the Combustion preheater module (CPM) and then resume this troubleshooting.
Hint: If Combustion preheater module (CPM) has software number 30796069 AA, the software is of an older version.
- Ignition on.
- Click on the VCT2000 symbol to erase the diagnostic trouble codes (DTCs). Erase diagnostic trouble codes (DTCs).
- Turn off the ignition.
- Remove the ignition key from the ignition switch.
- Disconnect VCT2000 from the vehicle's diagnostics socket.
- Remove the fuse for Combustion preheater module (CPM).
Note! If the heater is on, wait first until the heater is off. If the fan for combustion air is activated, the heater is on.
- Wait a couple of seconds.
- Reinstall the fuse/fuses.
- Ignition on. Then the control module restarts and performs internal checks. Certain malfunctions in the control module's software are detected only when the heater is started after having been off.
Continue - Checking the diagnostic trouble codes (DTCs)
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Checking the diagnostic trouble codes (DTCs)
- Ignition on.
- Connect VCT2000 to the diagnostics socket.
- Activate reading off diagnostic trouble codes (DTCs).
Has the diagnostic trouble code (DTC) been stored again?
Yes - Fault-tracing information 1
No - Fault-tracing information 2
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Fault-tracing information 1
When the diagnostic trouble code returns despite replacement of software, the only action is to replace the heater.
Continue - Fault-tracing information
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Fault-tracing information 2
When the diagnostic trouble code does not return after replacement of software, this indicates that the problem is no longer present.
Continue - Verification
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Verification
Hint: After carrying out the repair, check that the fault has been remedied.
- Ignition off.
- Restore components and connectors.
- Start the engine.
- Click the VCT2000 symbol to start activation. It takes approximately 180 seconds to carry out test.
This function checks both the heater's electrical and mechanical components and test runs the heater. In order for the test to start, the heater must not detect any flame, battery voltage must be over 10.25 V at 20 A consumption, the engine must be idling and the fuel lines must be full.
Note! Additional/parking heater not permitted to start, if the coolant's temperature is too high. The parking heater does not start if the temperature exceeds +65 °C till +75 °C. The exact temperature parameter depends on the software version. The additional heater does not start if the temperature exceeds approximately +75 °C. If the coolant is too warm, it can be cooled fast with the function Cooling of cooling system for Combustion preheater module (CPM).
A buzzing sound must come from the heater. The heater must now start and run.
Hint: If the control module detects a fault during the test, the diagnostic trouble code (DTC) is stored for the relevant component/function.
Note! The test cannot be started when the engine coolant heater run-on is active. Wait until run-on has finished.
Is the heater function OK?
Yes - Troubleshooting procedure complete
No - Fault-tracing information
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Fault-tracing information
Information
Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed.
Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.
Do you want to exit fault-tracing?
Yes - Exit fault-tracing
No - Attempt New Test
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Attempt New Test - Checking the software
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Fault-tracing information
Information
Fault-tracing information
In case of this defect, troubleshooting is not followed by verification.
The information can be displayed again or the fault-tracing for this fault can be interrupted.
Do you want to view the information again?
Yes - Attempt New Test
No - Exit Fault-tracing
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Attempt New Test - Checking the software
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