P1220Wysoki
Awaria układu sterowania przepustnicą (czujnik położenia przepustnicy 2 lub sterownik silnika). Kod producenta — znaczenie zależy od marki pojazdu (GM, Fiat, Isuzu).
Układ napędowy
Sprawdź szczegóły →P1635
Wysoki5V reference voltage circuit or glow plug relay circuit error (manufacturer code). The fault may concern sensors powered by 5V or the diesel engine starting system.
OBD-II (EN): 5V Reference Circuit or Glow Plug Relay Circuit Fault (Manufacturer Specific)
Code P1635 signals a problem with the 5V reference voltage circuit or glow plug relay — the meaning depends on the vehicle manufacturer. The fault can simultaneously cause incorrect readings from multiple sensors or problems starting a diesel engine in cold weather. Diagnostics require specialized equipment and electrical knowledge — a visit to a service center is recommended.
Symptoms
Engine hard to start (especially cold start in diesels), Check Engine light on, unstable engine idle, incorrect sensor readings (pressure, air flow, temperature), possible loss of power, simultaneous failure of multiple systems due to loss of 5V reference voltage.
Possible causes
• Damaged glow plug relay (Opel/Vauxhall diesel engines) • Short or open circuit in the ECM/PCM 5V reference voltage circuit (GM/Oldsmobile vehicles) • Damaged engine control module (ECM/PCM) — internal 5V regulation • Damaged or shorted wires/harness leading to 5V sensors • Damaged MAP, TPS, or other sensor causing overload on the 5V line
Affected systems
ECM/PCMobwód napięcia referencyjnego 5Vprzekaźnik świec żarowychczujnik MAPczujnik TPSczujnik pedału gazuukład rozruchu (diesel)
Related codes
P0380Średni
Świece żarowe — usterka obwodu (Opel)
Układ napędowy
Sprawdź szczegóły →Code P1635 appears in these brands
Go to messages and symptoms for your brand — there we analyze this code together with other typical alerts.
Does code P1635 require professional diagnostics?
The code alone is not enough. To find the cause, you need to read live data, check freeze frame conditions, and compare with vehicle behavior. Book a diagnostic session.