Code
P1298
CITROEN
P — Powertrain
Injector 4 control malfunction
Views:
UK: 4
EN: 11
RU: 7
AI status
Completed
Completed
100%
Causes
- Open or short in the injector 4 wiring harness
- Corroded or disconnected injector connector
- Faulty fuel injector (stuck, shorted coil or internal fault)
- Poor power supply or ground to injectors
- Faulty ECU injector driver/channel
- Intermittent connection due to damaged pins or terminal
Symptoms
- Check Engine Light (MIL) illuminated
- Rough idle or vibration, especially at idle
- Engine misfire felt or logged on cylinder 4 (P0304 may accompany)
- Reduced engine power or hesitation on acceleration
- Increased fuel consumption or black smoke from exhaust
- Intermittent starting problems or stalling
What to check
- Read freeze frame and live data with a scan tool — confirm P1298 and any related codes (P0204, P0304, etc.)
- Visually inspect injector 4 connector, pins and wiring for damage, corrosion or looseness
- Check fuse(s) and common power feed for the fuel injectors
- Measure injector 4 coil resistance at the connector (engine off) and compare to spec
- Backprobe injector 4 with a noid light or oscilloscope while cranking/running to confirm pulse signal
- Check battery voltage and ground integrity during cranking/running
Signal parameters
- Injector coil DC resistance (ohms) — compare to OEM spec
- Command pulse width (ms) measured on injector driver during running/cranking
- Injector supply voltage (approx. battery voltage with ignition ON)
- Ground continuity between injector connector and engine/ECU ground
- Noid light pulse presence (yes/no)
- Oscilloscope pattern: square/clean pulse from ECU, amplitude ~0–battery voltage
Diagnostic algorithm
- Use a scan tool: record freeze-frame, live data and confirm P1298 and any related codes (e.g., P0204, P0304). Clear codes and see if code returns.
- Visually inspect injector #4 connector and wiring for damage, corrosion, or loose terminals; repair as needed.
- With ignition OFF, measure injector #4 coil resistance at the connector and compare to spec. Replace injector if open or shorted.
- Check power and ground: verify battery voltage at the injector supply pin with ignition ON and confirm good ground at the injector body/ground circuit.
- With engine cranking or running, backprobe the injector control pin using a noid light or oscilloscope to confirm ECU is commanding the injector (pulse present and correct shape).
- If no command pulse but wiring intact, check continuity between ECU and injector connector; repair wiring as needed.
- Swap injector 4 with another cylinder’s injector and retest to determine if the fault follows the injector (injector fault) or remains on cylinder 4 (wiring/ECU).
- If wiring and injector are good and commands are absent or abnormal, test/replace the ECU injector driver per manufacturer procedures or consult specialist.
- After repairs, clear codes and perform a road or run test to ensure code does not return. Consider compression and fuel pressure checks if misfire persists.
Likely causes
- Broken or chafed wire to injector #4
- Connector contamination or bent pins at injector #4
- Injector 4 coil resistance out of specification (shorted or open)
- Blown fuse or poor common power feed to injector rail
- Faulty ECU output transistor for injector #4
- Mechanical injector fault causing abnormal current draw
Fault status
Status
Stored when the engine control module detects abnormal control or signal for fuel injector circuit #4 (open/short/intermittent or driver fault).
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours
Similar codes
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email