P23E0Cylinder 4 Fuel Heater Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P23E0 judges the effect of the cylinder 4 heater rather than its wiring: the circuit is intact, but the heat delivered or the temperature reached falls short of what the conditions call for. One factor specific to resistive heaters is supply voltage. Bosch specifies 260 W per heating element at 12 V; since power falls with the square of voltage, a weak battery at 10 V during cranking leaves only about 180 W, and warm-up takes noticeably longer. A performance code on one cylinder alone, however, points to that heater: an aged element, deposits or a poor contact. The engine control sets the heating demand from ethanol content and outside temperature, so the fault shows mainly in cold weather on high-ethanol fuel. No manufacturer documents P23E0; CARB expects functional monitoring.
- What you may notice
- Rough start in cold weather on high-ethanol fuel
- Longer cranking
- Engine warning lamp, depending on manufacturer
- Likely causes
- LikelyAged heater at cylinder 4 with reduced output
- PossiblePoor contact in the cylinder 4 heater circuit
- RareWeak battery or low system voltage during heating
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €80 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.