Short-Circuit to Ground
Short-circuit to ground
Checking the function of the flame sensor
- Ignition on.
Note! It is important that only the ignition is on in order for the heater to start.
- Activate the heater.
A buzzing sound should be heard from the heater.
Other information:
- For information about how the heater should operate when running, see Engine coolant heater, test running Engine Coolant Heater, Test Running
- For a description of parameters, see Description of parameters Description of Parameters
- For a description of activations, see Activating components/functions Activating Components/Functions.
Is the heater working?
Yes - Intermittent fault
No - Checking components and wiring
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Checking components and wiring
Check the cable between control module terminal #8 and the signal cable for the flame sensor. Check for a short-circuit to ground.
Hint: It is difficult to differentiate between the ground lead for the flame sensor and the signal cable. Take readings on one cable at a time to check for a relevant value on either of them.
Replace the flame sensor if no fault is found in the cable.
Remedy as necessary.
Other information:
- To access the control module or connect the breakout box, see Connecting the breakout box Connecting the Breakout Box
- To access or replace the flame sensor, see Overheat protection thermostat / flame sensor / engine coolant temperature sensor, replacing Service and Repair
- For other values, see Signal specification Signal Specification.
Continue - Verification
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Verification
Hint: After carrying out the repair, check that the fault has been remedied.
- Ignition off
- Reinstall the connectors, components etc.
- Ignition on.
Note! It is important that only the ignition is on in order for the heater to start.
- Activate the heater.
A buzzing sound should be heard from the heater.
Hint: After repair, the voltage of the flame sensor can be checked. The voltage should be a maximum of 1.0 V.
Check the function of the heater. See Engine coolant heater, test running Engine Coolant Heater, Test Running.
Other information:
- For a description of parameters, see Description of parameters Description of Parameters
- For a description of activations, see Activating components/functions Activating Components/Functions.
Does the heater operate?
Yes - VERIFIED
No - VERIFICATION FAILEDPAPER
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VERIFIED - Fault Found
VERIFICATION FAILED - Fault-tracing information
PAPER - No Fault Found
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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 - FAULT-TRACING FAILED
No - Attempt New Test
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FAULT-TRACING FAILED - FAULT-TRACING FAILED
Attempt New Test - Checking the function of the flame sensor
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Intermittent fault
Check the cable between control module terminal #8 and the signal terminal for the flame sensor. Check for an intermittent short-circuit to ground.
Remedy as necessary.
Other information:
- To access the control module or connect the breakout box, see Connecting the breakout box Connecting the Breakout Box
- For other values, see Signal specification Signal Specification
- Checking wiring and terminals Checking Wiring And Terminals.
Continue - Fault-tracing information
DONE
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Fault-tracing information
Information
Fault-tracing information
If the fault is intermittent, do not verify fault-tracing if the fault does not recur.
It is possible to view the information again, or leave fault-tracing for this diagnostic trouble code (DTC).
Do you want to view the information again?
Yes - Attempt New Test
No - Fault Found
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Attempt New Test - Checking the function of the flame sensor
FAULT-TRACING FAILED - DONE
FAULT FOUND - Fault Found
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