169796 - L33 SUPPLEMENTARY HEATER WILL NOT WORK IN "SUPPLEMENTARY HEATER" MODE

The effect of the supplementary heater cannot be felt under the specified operating conditions;
: activation of the supplementary heater in this mode is managed automatically by the climate control system mode and permitted only the following conditions occur simultaneously:

  • : activation of the supplementary heater in this mode is managed automatically by the climate control system mode and permitted only the following conditions occur simultaneously:
  • 1 key-on position
  • 2 coolant temperature lower than 30 c°
  • 3 interior temperature requirement higher than measured interior temperature
  • 4 engine rpm higher than 700 rpm
  • Fuel pump or coolant pump activation failure is diagnosed by the supplementary heater control unit
Fuel pump or coolant pump activation failure is diagnosed by the supplementary heater control unit
STEPOPERATIONS TO BE CARRIED OUTTEST RESULTS
1CHECK USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION
With the tester (Examiner or other instrument) connected, check the CAN network information for:

  • no control unit inactive;
  • no faulty control units;
  • no control units with faulty CAN line;
Move on to Step 1. Presence of faults1. Continue following the instructions for the diagnostic equipment
2. Climate control system node errorMove on to Step
3. Engine control node errorMove on to Step
2CHECK USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION
Keeping the diagnostic equipment (Examiner or other instruments) connected to the diagnostic socket, check:

  • for faults in the climate control system control unit
  • parameter plausibility
Move on to Step 1. Supplementary heater control unit faultMove on to Step
2. Presence of faults2. Continue following the instructions for the diagnostic equipment
3. Parameters not plausible3. Continue following the instructions for the diagnostic equipment
4. No communication between climate control system control unit4. Restore connection between the climate control unit and diagnostic connector (Wiring Diagram ) E6020 AIR CONDITIONING
3CHECK USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION
Keeping the diagnostic equipment (Examiner or other instruments) connected to the diagnostic socket, check:

  • that there are no faults in the engine management control unit
  • parameter plausibility
Move on to Step 1. Presence of faults 1. Continue following the instructions for the diagnostic equipment
2. Parameters not plausible2. Continue following the instructions for the diagnostic equipment
4CHECK USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION
Keeping the diagnostic equipment (Examiner or other instruments) connected to the diagnostic socket, check:

  • no faults in the supplementary heater control unit
  • parameter plausibility
Move on to Step 1. Presence of faults 1. Continue following the instructions for the diagnostic equipment
2. Parameters not plausible2. Continue following the instructions for the diagnostic equipment
3. No communication with the supplementary heater control unit3. Restore the connection between the supplementary heater control unit and the tester connector (Wiring Diagram ) E6020 AIR CONDITIONING
5CHECK USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION
Keeping the tester (Examiner or other instrument) connected to the tester input, activate the fuel feed pump in active diagnosis mode and check:

  • operation of the fuel system
Move on to Step Pipes leaky, broken or blockedRestore operation and change pipes if necessary     See in Op. 5020M34 FUEL SUPPLY PIPE TO ADDITIONAL INDEPEDENT HEATER ELECTRIC PUMP - R.R.
6CHECK USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION
Keeping the tester (Examiner or other instrument) connected to the tester input, activate the heater coolant circulation pump in active diagnosis mode and check:

  • operation of the coolant circulation system
Move on to Step Pipes leaky, broken or blockedRestore operation and change pipes if necessary     See in Op. 5020M50 ADDITIONAL INDEPENDENT HEATER WATER SUPPLY AND RETURN PIPES - R.R.
7CHECK ON CORRECT OPERATIONALL OKPROBLEMS ENCOUNTEREDACTION
Check that the fault is no longer presentFault persistsReplace supplementary heater unit     See in Op. 5020M10 independent heater unit - r r