Injection Timing / Injection Quantity
Fuel Balancing Control:
Fuel Balancing Control (6.7L) is an algorithm designed to reduce differences in injected fuel quantity from cylinder to cylinder. The increase in crankshaft speed due to individual cylinder combustion events is measured. The amount of fuel injected to each cylinder is then adjusted up or down to minimize the difference in increase in crankshaft speed from cylinder to cylinder. The total amount of fuel injected among all cylinders remains constant. The concept is shown in the graphic below.
FBC operates in closed-loop control in an engine speed range of 500-3000 rpm, and a commanded injection quantity of 3.5 - 90 mg/stroke. The maximum allowed correction in fuel quantity for an individual cylinder is given by the following table.
| Injection quantity requested before FBC correction (mg/stroke) | |||
| Maximum allowable FBC correction (mg/stroke): | 3.5 | 7.5 | 15 |
| 4 | 7 | 14 | |
The 3.2L engine uses a similar correction algorithm that operates at idle only.
| DTCs | P0263 - Cylinder #1 Contribution/Balance P0266 - Cylinder #2 Contribution/Balance P0269 - Cylinder #3 Contribution/Balance P0272 - Cylinder #4 Contribution/Balance P0275 - Cylinder #5 Contribution/Balance P0278 - Cylinder #6 Contribution/Balance P0281 - Cylinder #7 Contribution/Balance P0284 - Cylinder #8 Contribution/Balance P029A - Cylinder 1 - Fuel Trim at Max Limit P029B - Cylinder 1 - Fuel Trim at Min Limit P029E - Cylinder 2 - Fuel Trim at Max Limit P029F - Cylinder 2 - Fuel Trim at Min Limit P02A2 - Cylinder 3 - Fuel Trim at Max Limit P02A3 - Cylinder 3 - Fuel Trim at Min Limit P02A6 - Cylinder 4 - Fuel Trim at Max Limit P02A7 - Cylinder 4 - Fuel Trim at Min Limit P02AA - Cylinder 5 - Fuel Trim at Max Limit P02AB - Cylinder 5 - Fuel Trim at Min Limit |
| Monitor Execution | Continuous |
| Monitor Sequence | None |
| Sensors OK | Injector circuit codes, CKP, CMP, BARO, sensor supply voltage |
| Typical Monitoring Duration | 7.5 sec |
| Entry Condition | Minimum | Maximum |
| P0263-P0284 only: | ||
| Engine Speed | 500 rpm | 3000 rpm |
| Injection Quantity | 3.5 mg/stroke | 90 mg/stroke |
| Engine Coolant Temperature | 15 deg C | |
| Not In Regeneration | ||
| FBC wheel learn complete | ||
| P029A-P02AB only: | ||
| Engine coolant temperature | 40 deg C |
| P0266 - P2084:
If the current correction for the injector exceeds 90% of the allowable correction for current operation conditions, the code is set. P029A - P02AB: If specific cylinder balance quantity is >1.8 or <0.2 times normal fueling, a code is set. |