Code
P1293
LINCOLN
P — Powertrain
Injector High Side Open Bank 1
Views:
UK: 21
EN: 28
RU: 34
AI status
Completed
Completed
100%
Causes
- Blown or open fuse for injector power/feed
- Faulty fuel injector supply relay or fused power feed
- Damaged, corroded or disconnected wiring/connector in injector power feed (Bank 1)
- Open or internally failed fuel injector(s)
- Poor battery/charging system voltage
- Faulty ECM/high‑side driver or internal power distribution fault
Symptoms
- MIL (Check Engine Light) ON
- Rough idle, misfire(s) on one bank, reduced power or poor running
- Hard start or no‑start condition if all Bank 1 injectors lose power
- Possible stored/active misfire codes (P0300–P0306) in addition to P1293
- Low fuel trims or abnormal fuel system operation
What to check
- Read all stored and pending DTCs and freeze frame data; note engine conditions
- Visual inspection of injector wiring harness, connectors, and protective sleeving on Bank 1
- Check fuses and injector/fuel‑pump/injector feed relay for continuity and operation
- Measure battery voltage and charging system voltage (key ON and engine running)
- Backprobe the injector high‑side feed (power pin) for Bank 1 with key ON — should be battery voltage
- Command injectors ON with a scan tool while monitoring the high‑side feed and injector response
Signal parameters
- Injector high‑side supply voltage (Key ON, engine OFF): ~Battery voltage (≈ 11–14 V)
- Injector high‑side supply when commanded: pulses or maintained supply depending on circuit; should still show available supply referenced to battery
- Injector coil resistance: within factory spec (commonly ranges from ~0.5 Ω for low‑impedance to ~8–16 Ω for high‑impedance injectors) — compare to vehicle service data
- No continuity/open reading on high‑side feed = open circuit
- If ECM pulls high‑side (less common) then look for expected current/pulse behavior with scan tool
Diagnostic algorithm
- Retrieve all codes and freeze frame data; record conditions (battery voltage, engine load, RPM).
- Visually inspect Bank 1 injector connectors, pins and wiring for corrosion, damage, melted insulation, or disconnected pins.
- Check relevant fuses and the injector/fuel injector power relay; replace or bench test relay if suspect.
- With ignition ON (engine OFF) backprobe the high‑side power pin at one injector on Bank 1. Confirm battery voltage is present. If battery voltage is present, proceed to step 7.
- If no voltage at injector high‑side, trace the power feed back to fuse/relay and battery. Check continuity to the fuse and relay contacts and inspect splice points.
- Repair open wiring/connector/fuse/relay as found. After repair, clear codes and verify voltage restored and code does not return.
- If high‑side power is present but injector still not operating, command the injector ON with a scan tool while monitoring current/response. Measure injector coil resistance. A very high or infinite resistance indicates a failed/open injector — replace injector(s).
- Swap a known good injector from the other bank (or swap bank connectors) if practical to see if the fault follows the injector or stays with the wiring/bank.
- If wiring and injectors test good but ECM still reports open/high‑side fault, inspect ECM power/ground and harness connectors. Confirm ECM driver outputs and, if proper bench tests indicate ECM failure, consider ECM replacement only after all wiring and components are verified.
- After repairs, clear codes, perform key‑on/engine cranking checks and test drive to confirm no recurrence.
Likely causes
- Open circuit between battery/fuse/relay and Bank 1 injector rail (most common)
- Corroded/loose injector connector(s) or wiring harness chafing
- Blown fuse or failed injector power relay
- One or more injectors with open coil winding
- ECM driver fault (less common — confirm wiring first)
Fault status
Status
ECM detected open (no/high resistance) on the injector high‑side power feed for Bank 1 while commanding injectors.
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours
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