Signal Too High
Signal too high
Checking the water flow
Check if the lines to and from the heater are blocked, or if the heater is damaged causing the through flow to be restricted in some way.
Remedy as necessary.
Was a fault detected?
Yes - Verification
No - Checking the engine coolant temperature sensor
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Checking the engine coolant temperature sensor
- Start the engine
- Read off the coolant temperature in the heater.
Check that the engine coolant temperature (ECT) reading is correct. Compare with the actual coolant temperature of the engine.
Is the temperature reading OK?
Yes - Checking components and wiring
No - Checking components and wiring
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Checking components and wiring
Check the resistance of the engine coolant temperature sensor.
Remedy as necessary.
Other information:
- Signal specification Signal Specification
- Components resistance values Specifications
- Overheat protection thermostat / flame sensor / engine coolant temperature sensor, replacing Service and Repair
Continue - Verification
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Checking components and wiring
Check the fuel pump (FP) and combustion preheater module (CPM) connectors. Check for contact resistance and oxidation.
Check the cable between combustion preheater module (CPM) terminal #13 and fuel pump terminal 1. Check for an intermittent open-circuit.
Check the cable between combustion preheater module (CPM) terminal #11 and fuel pump terminal 2. Check for an intermittent open-circuit.
Note! Diagnostic trouble code (DTC) CEM-5F3B and/or diagnostic trouble code (DTC) CEM-5F3D may also be stored if there is a fault in the power cable.
Remedy as necessary.
Other information:
- Connecting the breakout box Connecting the Breakout Box
- Fuel pump auxiliary heater, replacing Service and Repair
- Overheat protection thermostat / flame sensor / engine coolant temperature sensor, replacing Service and Repair
- Checking wiring and terminals Checking Wiring And Terminals
Continue - Verification
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Verification
Verification
Verification
Hint: After carrying out the repair, check that the fault has been remedied.
- Ignition off
- Reinstall the connectors, components etc.
- Ignition on
- Read off the engine coolant temperature.
Note! It is important that only the ignition is on in order for the heater to start.
- Activate the heater.
Hint: After repair, the voltage of the flame sensor can be checked. The voltage must be a maximum of 1.0 V.
Check the heater function.
Caution! In order for to enable start of the heater itself, the battery voltage must be normal, coolant temperature must be lower than +96 °C and the heater's after-run/stop sequence must be finished. There must also be enough fuel in the tank.
Caution! If the heater or other components are not activated, try closing down the activation window and then starting the activation again with the symbol for VCT2000.
Other information:
- Engine coolant heater, test running Component Tests and General Diagnostics.
Is the heater working?
Yes - VERIFIED
No - VERIFICATION FAILEDPAPER
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VERIFICATION FAILED - Fault-tracing information
VERIFIED - Fault Found
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 water flow
FAULT FOUND - Fault Found
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