Meaning
The Powertrain Control Module (PCM) has detected an electrical malfunction in the fuel injection circuit of bank 2 (cylinders 2, 3, 5, and 8 on a V8 engine). The PCM continuously monitors injector resistance and signal, and this code activates when values fall outside the expected range.
Possible Causes
| Priority | Cause | Technical Details |
|---|---|---|
| 1 | Wiring Issues | Cut/chafed wires, short to ground or +12V, connector corrosion |
| 2 | Faulty Injector | Internal coil short circuit (≈ 0Ω) or open circuit (infinite resistance) |
| 3 | Damaged Connectors | Oxidized, bent, or improperly seated pins (especially on bank 2) |
| 4 | PCM Failure (rare) | Internal computer problem (failed injector driver module) |
Observable Symptoms
- ⚠️ Check Engine Light On (MIL)
- Rough idle or vibrations
- Noticeable power loss
- Increased fuel consumption
- Hard starting (if multiple injectors affected)
- Code often accompanied by misfires (P0302, P0303, P0305, P0308)
Diagnostic Procedure (Step by Step)
- Visual Inspection (Bank 2):
- Examine injector harnesses (cylinders 2,3,5,8): look for burn marks, chafing against hot components.
- Disconnect connectors: check for corrosion/oxidation (green/white spots).
- Basic Electrical Test:
- Measure injector resistance (cold engine):
- Normal value: 10-20 Ω (typical Ford).
- Abnormal: < 5Ω (short circuit) or > 30Ω (open circuit).
- Measure injector resistance (cold engine):
- Circuit Check:
- Use a multimeter to verify:
- Continuity between PCM and injectors.
- No short circuit to ground (diode test).
- Use a multimeter to verify:
- Power Test:
- Connect a Noid Light (injector test LED): irregular flashing = PCM signal problem.
- Analyze waveform with oscilloscope (expected peak: 40-80V).
Repair Solutions
| Confirmed Cause | Action |
|---|---|
| Failed Injector | Replace faulty injector (always compare resistances) |
| Damaged Wiring | Repair harness with waterproof solder + heat sleeve |
| Corroded Connector | Clean with electrical contact cleaner or replace connector |
| Defective PCM | Verify 12V supply to driver module before PCM replacement |
Key Technical Data
- Bank 2 Location:
- V6/V8 Engine: Side opposite exhaust (often driver side in US).
- Resistance Tolerance: ±15% of specified value.
- Common Mistake: 80% of P1292 codes are caused by connector issues (moisture, vibrations).
Pro Tip: After repair, reset fuel adaptations with a diagnostic tool (e.g., Forscan) and perform a drive cycle to verify code disappearance.