Vanguard 25E300, Repair Manual

Page: 46 / 104

SPN 651, FMI 3: Voltage High/Open
Step Action Yes No
1 1. Perform the Injector Cylinder 1 Firing Test. See TEST PROCEDURES in this
section.
2. Did the test Pass?
Problem does not currently exist. Go to step 2.
2 1. Turn Ignition OFF.
2. Disconnect fuel injector connector.
3. Install Briggs & Stratton Noid Light (Part No. 19623).
4. Crank the engine.
5. Does Noid Light flash? Replace fuel injector. Go to step 3.
3 1. Turn Ignition OFF.
2. Remove Noid Light and connect fuel injector connector.
3. Back probe (using fused patch cord) terminal 1 (Yellow wire) of fuel injector
connector.
4. Connect terminal 1 back probe to red meter test lead on DVOM.
5. Connect black meter test lead to a known good ground.
6. Set DVOM to read volts DC.
7. Turn Ignition ON, Engine OFF.
8. Does DVOM read 12.2-13.5 volts DC?
Go to step 4. Reading is below
12.2 volts DC.
Perform visual
and continuity
check of 10 amp
Battery fuse (Red).
4 1. Turn Ignition OFF.
2. Disconnect fuel injector electrical connector.
3. Disconnect ECM connector.
4. Back probe terminal 2 (Lt. Blue/Black wire) of fuel injector connector.
5. Connect terminal 2 back probe to red meter test lead on DVOM.
6. Back probe terminal M2 (Lt. Blue/Black wire) of ECM connector.
7. Connect terminal M2 back probe to black meter test lead on DVOM.
8. Set DVOM to read resistance.
9. Does DVOM read less than 0.5 ohms? Control circuit is OK. Reading is above 0.5
ohms. Check terminals
for corrosion or replace
EFI wire harness.
NOTE: IF DTC
still present after
replacement of EFI
wire harness, then
replace ECM due to
failed injector driver.
47
Not for
Reproduction