Volvo All Engines (2010 Emissions) Fault Code: SPN 729 FMI 3 PID: SID 70 Intake Air Heater (IAH) 1

The preheat function is used to warm up the inlet air during cold conditions both before and after cranking to make the starting easier and better for the environment at very low temperatures. This diagnostic trouble code (DTC) detects a faulty preheat function.

Conditions for diagnostic trouble code (DTC):
1) The voltage at pin A14.EB:7 is more than 91?% battery voltage

Diagnostic operating conditions
1) Ignition key in ON position

Observable symptoms
1) Intake air heater (IAH) relay may be constantly activated
2) High intake air temperature (IAT)
3) High current consumption
4) Power loss
5) Low battery voltage

Probable cause
1) Connector
2) Wiring harness
3) Intake air heater (IAH) relay