OBD-II trouble code
P0284: Cylinder 8 Contribution/Balance
SAE J2012 APR2002: cylinder 8 contribution/balance. It is the last contribution code on both GM diesel bulletins. The printed pair is one injector after the crank is even.
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 19-NA-232 rules compression out; the LWN charge-air repair and a compression repair are outside this pair)
- DIY difficulty
- Shop recommended
Browse every code in P0200–P0299, or start from the full code library.
What does P0284 mean?
SAE J2012 APR2002 names P0284 Cylinder 8 Contribution/Balance. P0282 and P0283 are the circuit codes, and on a 6.0L they are current tests, not this quantity test. A VAG-group list prints 16668 P0284 as a fuel-injection quantity deviation on cylinder 8.
19-NA-232 (NHTSA MC-10168238) lists P0284 as the last contribution code in its additional-DTC paragraph, after P0263, P0266, P0269, P0272, P0275, P0278, and P0281. The vehicles are 2017–2020 Silverado and Sierra with the L5D and L5P, and the cab-chassis years that header adds, with P0300 through P0308. Causes: fuel injector, electrical issue, or loss of cylinder compression. Pull the underhood fuel-pump control module B+ fuse, crank without fuel, and compare the downward dips in battery voltage. The scope is across the battery, and the dip is voltage dropping as the starter draws more current on a compression stroke. The bulletin says a graph that passes gives no reason to think the engine is mechanically wrong. It does not say an even graph proves the injector. It takes compression off the list.
17-NA-194 (NHTSA MC-10166641) also ends its contribution list at P0284. The vehicles are 2016–2020 LWN Colorado, Canyon, Express, and Savana. The cause is an induction leak. The test is the full-system charge-air leak test. Cylinder 9 codes are not on either bulletin.
LBT-149 records Duramax balance rates for cylinders 1–8, so cylinder 8 is the last channel there too. The windows are +4 mm³ to −4 mm³ in Neutral or Park and +6 mm³ to −6 mm³ in Drive, coolant above 82°C, idle more than 30 seconds, parking brake applied, brake held in Drive. SB-10030789's cylinders 1 through 4 do not include cylinder 8. PIP5537 says not to replace injectors for the 2017–2018 L5P misfire it describes and names P0300, not P0284. A claim that cylinder 8 is starved because it is the last injector on a rail is not in these documents.
Common causes
- On a 19-NA-232 truck, loss of compression at cylinder 8
- A fuel injector or an electrical fault on that bulletin after the battery-voltage dips match the other cylinders
- On a 17-NA-194 LWN, an induction-system leak
- A Duramax cylinder 8 quantity outside +4 mm³ to −4 mm³ in Park or outside +6 mm³ to −6 mm³ in Drive
Symptoms
- P0284 stored
- P0300 through P0308 on a truck the 19-NA-232 header covers
- An LWN with one or more of the other codes 17-NA-194 lists
- Eight Duramax balance rates, with cylinder 8 the last one recorded
- P0283 stored, which on a 6.0L is high injector current and a different test
Diagnostic steps
- 1.If P0282 or P0283 is stored, diagnose the circuit. On a 6.0L that is a current test and does not answer a contribution question.
- 2.On a listed L5D or L5P, remove the FPCM B+ fuse, crank, compare downward dips in battery voltage, refit the fuse, clear the codes the open fuse created. A weak voltage dip is mechanical. An even voltage trace removes compression from the cause list.
- 3.On a listed LWN, run the full-system charge-air leak test. Stop there if it finds the leak. The injector is not that bulletin's correction.
- 4.On the Duramax LBT-149 describes, record cylinders 1 through 8 in both gears and keep the windows apart. Other DTCs besides P0300–P0308 go to the code list first.
- 5.Do not extend either bulletin past P0284. Cylinder 9 is a different code and a different page.
- 6.Depressurize before an injector is opened. The printed pair is one injector after compression is not low.
Repair cost
$768 – $953 (one fuel injector replacement, parts and labor, after 19-NA-232 rules compression out; the LWN charge-air repair and a compression repair are outside this pair)
RepairPal national injector replacement, 3 September 2026, is $768–$953, labor $304–$446, parts $464–$507. The printed pair is that one injector on the 19-NA-232 path once the cranking trace is even. 17-NA-194's charge-air repair and a compression repair were searched and are not this number. Diagnosis is $125–$183 labor, separate. The Silverado 1500 fuel-filter line at $290–$415 is outside both the national filter price and this injector pair. The 2026 F-150 injector line at $1,130–$1,415 is also outside.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with fuel injector replacement preselected. Adjust labor rate and vehicle category to fit your situation.
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.