Powertrain
generic / SAE
P0543
Intake Air Heater A Circuit Open
The intake air heater (grid heater) on path A - used on cold-start of diesel engines to warm intake air for reliable combustion - has an open control circuit. Without it, cold-start emissions and idle quality on cold days suffer.
SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number5 / 43
Possible causes
- Open in harness, relay or heater element high
- Pin pushed back out of connector body low
- Cracked solder joint inside the module or sensor low
Inspection / repair
- Difficulty: medium
- DIY: possible
- Estimated cost: 120–500 €
- Estimated time: 0.6–2 h
- Component: intake air heater a
- Component: heater a relay
- MIL / check engine light
- emissions-relevant
Sources
References
sae:J2012