P0543 on RAM
Intake Air Heater A Circuit Open
P0543 on RAM vehicles indicates intake air heater a circuit open. Au7o has documented this code across 1 RAM model — most commonly on 3500. This code indicates the engine computer detected an open circuit in the intake air heater control circuit, meaning current is not flowing as expected. The intake air heater preheats incoming air for better cold starts and emissions. An open circuit means the heater is likely not functioning, which mainly causes harder cold starting and possible white smoke at startup. Typical repair costs on RAM range from $80 to $250, depending on the specific model and root cause.
Common Causes of P0543
- •Failed (burned-out) intake air heater element
- •Broken or corroded wiring to the heater
- •Faulty intake heater relay
- •Loose or disconnected connector
- •Blown heater fuse
- •PCM driver fault
P0543 on RAM by Model
RAM 3500(1 issue)
- Grid Heater Relay Failure (6.7L Cummins)2010-2025
The intake grid heater relay fails, preventing the grid heater from warming intake air during cold starts. The grid heater draws significant current (up to 200 amps), and the relay contacts eventually burn and weld or fail open. Without the grid heater, cold-start performance degrades significantly in temperatures below 40°F — longer cranking, white smoke, rough idle, and potential no-start conditions in extreme cold.
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View P0543 across all makes →Frequently Asked Questions
What does P0543 mean on RAM?▼
P0543 stands for "Intake Air Heater A Circuit Open." This code indicates the engine computer detected an open circuit in the intake air heater control circuit, meaning current is not flowing as expected. The intake air heater preheats incoming air for better cold starts and emissions. An open circuit means the heater is likely not functioning, which mainly causes harder cold starting and possible white smoke at startup. On RAM specifically, this code is documented across 1 model.
What causes P0543 on RAM vehicles?▼
Common causes on RAM: Failed (burned-out) intake air heater element, Broken or corroded wiring to the heater, Faulty intake heater relay, Loose or disconnected connector, Blown heater fuse. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0543 on a RAM?▼
Repair costs on RAM range from $80 to $250, depending on the specific model and root cause.
Which RAM models have P0543 documented?▼
Au7o has documented P0543 on 1 RAM model: 3500.