P029C code meaning
Cylinder 1 - Injector Restricted
Powertrain system Generic code P02xx codes Check engine light
What P029C means
These codes belong to an individual-cylinder fuel correction: a diesel's cylinder balance control measures each cylinder's crankshaft acceleration and adjusts its injection quantity; on gasoline engines a cylinder-selective mixture control does the same. CARB requires the system to report when such a correction has used up its range or one cylinder causes an imbalance. P029C means the module attributes the deviation of cylinder 1 to an injector delivering too little – deposits or a sticking nozzle needle. GM's 2.8 litre Duramax lists it as a stuck-injector fault in its cylinder balance system, which then switches the balance control off. GM and Ford use other codes for this (P0263 ff, P219A ff); no manufacturer document describing this code with thresholds was found, so the description follows CARB and published patents.
P029C at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor1 to 4 hours
- Clears after repairAfter a drive cycle
Symptoms of P029C
- Check engine light on
- Rough idle, vibration
- Lack of power, higher consumption or smoke
Common causes of P029C
- Most likelyDeposits or coking at the nozzle of cylinder 1
- PossibleNozzle needle sticking
- PossibleContaminated fuel or water
- PossibleInjector circuit high-resistance
- Less likelyCompression loss mimicking low output
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Fuel injector cylinder 1Crankshaft position sensorEngine control module
What each part of P029C means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 2 | Area: fuel and air metering (injector circuit). |
| 9C | The exact fault in that area. |
What to do next
- Note P029C and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P029C
What does P029C mean?
P029C means "Cylinder 1 - Injector Restricted". These codes belong to an individual-cylinder fuel correction: a diesel's cylinder balance control measures each cylinder's crankshaft acceleration and adjusts its injection quantity; on gasoline engines a cylinder-selective mixture control does the same. It is a generic code, so it means the same on every make.
Is it safe to drive with P029C?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P029C fail an emissions test?
Yes, it can. P029C is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P029C to fix?
Difficulty: medium. A typical repair takes 1 to 4 hours of work. This is a job for a workshop.
Will P029C clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.