TEST
ACTION
APPLICABILITY
10
Turn the ignition off.
Disconnect the Fuel Injector harness connector.
Ignition on, engine not running.
NOTE: When a Misfire is detected for a particular cylinder, the PCM will
shut down that cylinders Injector Control circuit.
With the DRBIII
t, erase DTCs.
Using a 12-volt test light connected to 12-volts, probe the Injector Control circuit.
With the DRBIII
t, actuate the Fuel Injector.
Does the test light blink/flicker?
All
Yes
→ Replace the Fuel Injector.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
No
→ Go To 11
11
Turn the ignition off.
Disconnect the Fuel Injector harness connector.
Disconnect the PCM harness connectors.
CAUTION: DO NOT PROBE THE PCM HARNESS CONNECTORS. PROBING
THE PCM HARNESS CONNECTORS WILL DAMAGE THE PCM TERMI-
NALS RESULTING IN POOR TERMINAL TO PIN CONNECTION. INSTALL
MILLER SPECIAL TOOL #8815 TO PERFORM DIAGNOSIS.
Check the Injector Control circuit for an open, short to ground, and short to voltage.
Was a problem found with the Injector Control circuit?
All
Yes
→ Repair the excessive resistance or short in the Injector Control
circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
No
→ Go To 17
12
Turn the ignition off.
Warning: The fuel system is under a constant pressure (even with the engine
off). Before testing or servicing any fuel system hose, fitting or line, the fuel
system pressure must be released.
Raise vehicle on hoist, and disconnect the fuel pressure line at the fuel pump module.
Install special tool #6539 (5/16
9) fuel line adapter fuel pressure gauge between the
fuel supply line and the fuel pump module.
Ignition on, engine not running.
With the DRBIII
t, actuate the ASD Fuel System test and observe the fuel pressure
gauge.
NOTE: Fuel pressure specification is 400 KPa +/- 34 KPa (58 psi +/- 5 psi).
Is the fuel pressure within specification?
All
Yes
→ Repair or replace fuel supply line as necessary.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
No
→ Go To 13
13
Turn the ignition off.
Warning: The fuel system is under a constant pressure (even with the engine
off). Before testing or servicing any fuel system hose,fitting or line, the fuel
system pressure must be released.
Remove the Fuel Pump Module and inspect the Fuel Inlet Strainer.
Is the Fuel Inlet Strainer plugged?
All
Yes
→ Replace the Fuel Pump Inlet Strainer.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
No
→ Test Complete.
95
DRIVEABILITY - SBEC
P0300-MULTIPLE CYLINDER MIS-FIRE —
Continued