Webasto Thermo Pro 90 Series Service Installations page 21

Thermo Pro 90
Symptom
F Excessive smoke from
heater during heating
phase
G Heater running, vehicle
interior cold
H Excessive smoke from
heater during afterrun-
ning phase
I Fuel odour
J Smell of exhaust in vehi-
cle interior
K Coolant loss
Possible cause Corrective measures
DP42 fuel pump See symptom B, DP42 fuel pump
Fuel See symptom C, fuel integration
integration
Exhaust system and air See symptom C, exhaust system and air intake system
intake system
Burner unit See symptom C, burner unit
Vehicle blower –
–
–
–
Exhaust system and air See symptom C, exhaust system and air intake system
intake system
Fuel See symptom C, fuel integration
integration
DP42 fuel pump See symptom B, DP42 fuel pump
Glow plug See symptom A, glow plug
Exhaust system and air See symptom C, exhaust system and air intake system
intake system
U4840 coolant pump See symptom B, coolant pump
Coolant circuit See symptom D, coolant circuit
5 Malfunctions and troubleshooting
Check fuse F1
Check coolant temperature (K5 switches at approx. 30 °C)
Check switching signal at relay K5, ground at Pin 85 and positive at
Pin 86, (audible, see wiring diagram in general installation
instructions)
Check coolant temperature signal line (green/white, gr/ws), Pin 86 at
K5
507