GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The pressure limiter opens when abnormally high pressure is generated, releasing the pressure. When the common rail pressure reaches approximately 140 MPa (1,420 kg/cm²), the pressure limiter opens. When the pressure drops to approximately 30 MPa (310 kg/cm²), the pressure limiter works to maintain the pressure, thereby enabling continuous running.

The common rail pressure sensor, installed at left end of the common rail, is used to detect fuel pressure.

A special gasket is used at the connection part with the common rail body so as to seal high pressure fuel.

Conditions for Running the DTC

    • The desired idle speed control (ISC) speed, as detected by the scan tool and common rail pressure, is not controlled.
    • DTC 0245, 0115, 0217, 0247 or 0248 are not set.
    • The crankshaft position (CKP) sensor is in a normal condition.
    • The pump is in normal mode.
    • The battery voltage is higher than 8 volts.
    • The pump speed is higher than 450 RPM.
    • The engine coolant temperature (ECT) is higher than 60°C (140°F)

Conditions for Setting the DTC

    • The pressure control valve (PCV) opening timing reached the limited value or the feedback value reaches -60 CA degrees.
    • The above conditions are met for 30 cycles.

Action Taken When the DTC Sets

    • The ECM will illuminate the malfunction indicator lamp (MIL) the first time the fault is detected.
    • Injection amount is limited for 60 mm³/seconds

Conditions for Clearing the MIL/DTC

    • The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
    • A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
    • A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
    • Clear the MIL and the DTC with a scan tool.

DTC 0226 can be cleared by using the Clear Info on the scan tool or by using the Diag Clear Switch.

Diagnostic Aids

Inspect for the following conditions:

    • Poor connection at the ECM
        Inspect the harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal-to-wire connection.
    • Smoke, power shortage, due to lack of common rail pressure. The pressure limiter is activated.
    • Inspect the fuel filter.

Step

Action

Yes

No

Schematic Reference: Engine Controls Schematics

1

Important:  If the PC sensor or PCV malfunction, repair them first.

Does DTC 0226 set while the ignition is ON or the engine is running?

Go to Step 2

Go to Diagnostic Aids

2

Inspect for the following conditions:

    • An injection pipe malfunction
    • Inactive pressure limiter

Is the fuel shortage flag set?

Go to Step 7

Go to Step 3

3

Clear all DTCs.

Does DTC 0226 reset?

Go to Step 5

Go to Step 4

4

Important: When the PC sensor low pressure output is fixed, DTC 0226 or 0227 will set.

Inspect the ECM connector, the ECM ground, and the pressure control (PC) sensor connector for poor connections.

Did you find and correct the condition?

Go to Step 10

--

5

Inspect for an abnormal supply pump or sticking pump.

Did you find the problem?

Go to Step 8

Go to Step 10

6

Clear all DTCs.

Does DTC 0226 reset?

Go to Step 9

System OK

7

Replace the pressure limiter.

Did you complete the replacement?

Go to Step 10

--

8

Replace the supply pump.

Did you complete the replacement?

Go to Step 10

--

9

Replace the ECM. Refer to Engine Control Module Replacement/Restore Fuel Rate Data .

Did you complete the replacement?

Go to Step 10

--

10

Clear all DTCs.

Does DTC 0226 reset?

Go to Step 1

System OK