Description

Fuel Injectors Description

1. Fault Codes:
P0201 Cylinder 1 Injector Circuit Malfunction
P0202 Cylinder 2 Injector Circuit Malfunction
P0203 Cylinder 3 Injector Circuit Malfunction
P0204 Cylinder 4 Injector Circuit Malfunction
P0205 Cylinder 5 Injector Circuit Malfunction
P0206 Cylinder 6 Injector Circuit Malfunction
P0207 Cylinder 7 Injector Circuit Malfunction
P0208 Cylinder 8 Injector Circuit Malfunction
P1201 Cylinder 1 Injector Circuit open/short to ground
P1202 Cylinder 2 Injector Circuit open/short to ground
P1203 Cylinder 3 Injector Circuit open/short to ground
P1204 Cylinder 4 Injector Circuit open/short to ground
P1205 Cylinder 5 Injector Circuit open/short to ground
P1206 Cylinder 6 Injector Circuit open/short to ground
P1207 Cylinder 7 Injector Circuit open/short to ground
P1208 Cylinder 8 Injector Circuit open/short to ground

2. Monitoring Procedure

Summary
Problems with the injectors are detected using two tests, the first cannot distinguish between open circuit and short to battery or ground faults. The second isolates the short to battery condition.

Injector Hardware Test
This test determines whether the flag, INJ DIAG INJ BUFF STATUS [1.NCYLS] indicates a fault event while the vehicle status is ENGINE RUNNING. If a fault event has occurred, then increment that injectors' fault counter, INJ DIAG INJ FAULT CNTR [1.NCYLS], up to a limit of INJ DIAG FAULT LIMIT. If INJ DIAG NO FAULT LIMIT consecutive no fault events occur, then that injectors' fault counter is decremented, down to a limit of zero. If the count reaches INJ DIAG FAULT LIMIT then an injector hardware fault is present.

Injector Open Circuit or Ground Short Test
This test determines whether the flag, INJ DIAG INJ BUFF STATUS [1.NCYLS] indicates a fault event while the engine is in the STALL condition or during ECU POWER DOWN. If a fault event has occurred, then increment that injectors' fault counter, INJ DIAG OC FAULT CNTR [1.NCYLS], up to a limit of INJ DIAG FAULT LIMIT. If INJ DIAG NO FAULT LIMIT consecutive no fault events occur, then decrement that injectors' fault counter, down to a limit of zero. If the count reaches INJ DIAG FAULT LIMIT then an injector open circuit or ground short fault is present.

3. Primary Detection Parameter
Hardware fault status from injector drive ASIC which monitors line voltage before low side drive transistor.

4. Fault Criteria Limits
Injector Diagnostic Fault limit = 10; limit used to define that there is a fault present with the injector.
Injector Diagnostic/no Fault limit = 40; limit used to define that there is not a fault present with the injector.

5. Monitoring Conditions
The injector hardware diagnostic will be run when the vehicle status is engine running.
The injector open circuit or ground short test will be run when the engine is in stall or during ECM power down.

6. Monitoring Time Length / Frequency of Checks
The injector hardware diagnostic will be run at a frequency of 10Hz while the engine is running.
The injector open circuit or ground short test will be run whenever the engine is in the stall condition or during ECM power down.

7. Criteria for Storing Fault Code
Two successive trips where the diagnostic routines indicate a failed injector or injector circuit.

8. Criteria for Illuminating MIL
Two successive trips where the diagnostic routines indicate a failed injector or injector circuit.

9. Criteria for Determining Out of Range Input Signals
The injector diagnostic sampling technique monitors non-linear signals; the criteria will be signal/no signal.