OBD-II trouble code
P0271: Cylinder 4 Injector Circuit High
SAE J2012 APR2002: cylinder 4 injector circuit high. The 2009 BMW M5 S85 stores a short to B+ under hex 276A and limits speed to 5000 rpm. The printed pair is one injector after the harness step.
Quick facts
- System
- Powertrain
- Category
- Fuel Injectors
- Severity
- Medium severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $768 – $953 (one fuel injector replacement, parts and labor, after the 2009 M5 harness step or the G3/G8 wiring tests; the short to B+ and the module are outside this pair)
- DIY difficulty
- Shop recommended
Browse every code in P0200–P0299, or start from the full code library.
What does P0271 mean?
SAE J2012 APR2002 names P0271 Cylinder 4 Injector Circuit High. A VAG-group list prints 16655 P0271 as injector 4-N33, short to positive.
The 2009 BMW M5 (E60) S85 page files 276A - P0271 as the electrical diagnosis of cylinder 4's fuel injector. The memory line is a short circuit to B+. Terminal 15 on, and battery voltage above K_ED_PlusMin, are the identification conditions. Step 1 is the plug and the wiring harness. Step 2 is the valve, replaced as indicated. The effect line limits engine speed to 5000 rpm, with rough idle, power reduction, and the MIL after two engine runs. The 2007 M5 page uses hex 276A for P0270, a short to ground, and a 3500 rpm limit. Same hex, other year, other code. Do not carry the 3500 rpm line onto this page.
The 2009 G3 1.6L setting line for P0271 is a control circuit shorted to voltage. The open and the short to ground are P0270. On the 7.5–16 V Type A procedure, AllOEMManuals G3 L4-1.6L and gm.saturn.team 7725/145178, terminal 1 is ignition and must light a test lamp before the control wire is judged. Terminal 2 is control. J 34730-405 between control terminal 2 and ignition terminal 1 should flash with the engine running. Document 8100/175665 prints terminal 2 as ignition, terminal 1 as control, 11–16 volts, and Type B, so this pinout is not every 2009 G3 connector. Always off is where the chart says to test a short to voltage or an open. The setting sentence for this code is the short to voltage, so an open found on that branch is written as P0270's fault, not renamed. Always on is a short to ground and is the other code. That procedure is Type A, commands open-loop fuel, and enables at 7.5–16 volts.
The 2008 G8 times P0271 as a short to voltage for greater than 4 seconds or a cumulative of 30 seconds. After the supply lamp on the ECM side of the multi-way is proved, a lamp from the control pin to ground must stay dark. Light means a short to voltage, and the ECM comes only after the wire tests normal. An open on that car is P0204. The G3's 11–14 ohm, 10–32°C window does not belong on the G8, whose coil test is 12–16 ohms with no temperature printed.
Common causes
- On the 2009 M5, a short circuit to B+ in cylinder 4's injector driver info, fault 276A
- A short to B+ in that injection valve's plug or harness
- On the 7.5–16 V Type A G3 procedure, injector 4's control circuit shorted to voltage
- On the G8, that short held for greater than 4 seconds or a cumulative of 30 seconds
- The ECM driver, after the control wire on that chart tests normal
Symptoms
- P0271 stored
- On the 2009 M5 page, engine speed limited to 5000 rpm and power reduced
- A G3 injector lamp that stays off after terminal 1 has lit
- A G8 control lamp to ground that comes on
- Open-loop fuel when the G3 Type A code sets
Diagnostic steps
- 1.On the 2009 M5, check the plug and harness before the valve. Keep the 5000 rpm effect on this year. The 2007 276A page is the ground code.
- 2.On the 7.5–16 V Type A procedure, ignition off, unplug cylinder 4. Key on, ignition terminal 1 to ground must light. A dark lamp is the ignition feed, a short to ground or an open, fuse included, and it is not the short to voltage that sets this code. An open on that procedure is P0270. The G8 stores an open as P0204. The 2007 M5 page for hex 276A is P0270.
- 3.Then J 34730-405, engine running. Always off: test the short to voltage, and test the open separately. Replace the ECM only if the wire is normal. Always on is not this code. Stay off the belt and the fan.
- 4.On the G8, do not skip the supply lamp. A dark supply lamp with an open fuse is a short to ground in the ignition feed, which is not a control-circuit short to voltage.
- 5.Ohms on the 7.5–16 V Type A procedure: 11–14 at 10–32°C between ignition terminal 1 and control terminal 2. G8 12–16 with no window printed. The M5 276A page prints neither. Document 8100/175665 measures the other way.
- 6.Depressurize before removal. The printed pair is the injector. The B+ short and the module are outside it.
Repair cost
$768 – $953 (one fuel injector replacement, parts and labor, after the 2009 M5 harness step or the G3/G8 wiring tests; the short to B+ and the module are outside this pair)
The RepairPal national injector total updated 3 September 2026 is $768–$953, labor $304–$446 and parts $464–$507. Printed here for the valve or injector the named chart replaces after the wiring step. A short to B+, a fuse, and an ECM or DME are outside. Diagnosis labor of $125–$183 is separate. Other estimator lines, such as the 2026 F-150 at $1,130–$1,415, are not the national pair.
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DIY vs shop
Leave this one to a qualified shop. The barrier here is high-pressure fuel components, where residual pressure remains after shutdown and escaping fuel can penetrate skin. DIY attempts often produce a more expensive problem than the original code.