127
DTC 651 Injector Short/Open
Step
Action
Value(s)
Yes
No
1
Did you perform the On-board diagnostics
(OBD) system check?
Go to Step
(2)
Go to On-
Board Diag-
nostics
System
Check/Malfun
ction indicator
lamp.
2
For DTC 651-3 short to B+, Go to Step (3)
For DTC 651-5 Open Circuit, Go to Step (5)
For DTC 651-6 Short to Ground, Go to Step
(11)
3
Disconnect injector connector
Key
OFF
Disconnect
ECU-B
Is resistance between pin Measure voltage
from pin injector pin 2 to ground.
Is voltage greater than zero?
>0V
Go to Step
(4)
4
Key OFF, disconnect ECU-B
Key ON, measure voltage from pin 2 to
ground.
Is voltage greater than zero?
>0V
Repair short
to power in
the harness.
Go to step14
Replace
ECU. Go to
Step (14)
5
For affected cylinder, disconnect injector
connector, Key ON
Measure voltage from pin 1 to ground.
Is battery voltage present?
Battery Vol-
tage
Go to Step
(8)
Go to Step
(6)
6
With C007 disconnected, Key ON
Measure voltage at C007 pin 2
Is battery voltage present?
Battery Vol-
tage
Repair open
in harness
between
C007 and in-
jector
connector.
Go to Step
(14)
Go to Step
(7)
7
Key OFF, disconnect ECU-B.
Measure resistance from C007 pin 1 to ECU-
B pin A1
Is resistance less than 5
Ω
?
<5
Ω
Refer to the
wiring dia-
gram for your
truck and re-
pair power
supply prob-
lem. Go to
Step (14)
Repair open
in the har-
ness. Go to
Step (14)
8
Measure resistance of affected injector.
Is resistance 2
Ω
± .5
Ω
?
2
Ω
± .5
Ω
Go to Step
(9)
Replace in-
jector. Go to
Step (14)
Summary of Contents for 3.0L GM
Page 4: ...4 ...
Page 5: ...5 General Information ...
Page 9: ...9 Maintenance ...
Page 16: ...16 ...
Page 17: ...17 LPG Fuel System ...
Page 18: ...18 LPG FUEL SYSTEM OPERATION ...
Page 25: ...25 LPG Closed Loop Schematic ...
Page 26: ...26 ...
Page 27: ...27 LPG System Diagnosis ...
Page 35: ...35 Fuel Symptom Diagnostics ...
Page 51: ...51 Electrical Section ...
Page 52: ...52 ...
Page 53: ...53 DST Diagnostic Scan Tool ...
Page 59: ...59 Select the USB button then click the OK box Click on the Search attached device box ...
Page 67: ...67 When connected the live data stream appears in the Value column ...
Page 78: ...78 ...
Page 80: ...80 ...
Page 81: ...81 Engine Wire Schematic ...
Page 82: ...82 2011 3 0L GM Engine IMPCO Emission Certified LPG Fuel System ...
Page 83: ...83 ...
Page 84: ...84 ...
Page 85: ...85 Engine Wire Harness Repair ...
Page 89: ...89 Diagnostic Trouble Codes DTCs ...
Page 93: ...93 ...
Page 101: ...101 ...
Page 105: ...105 ...
Page 109: ...109 ...
Page 119: ...119 ...
Page 129: ...129 ...
Page 133: ...133 ...
Page 137: ...137 ...
Page 141: ...141 ...
Page 145: ...145 ...
Page 161: ...161 ...
Page 165: ...165 ...
Page 169: ...169 ...
Page 173: ...173 ...
Page 201: ...201 ...
Page 209: ...209 ...
Page 213: ...213 ...
Page 217: ...217 ...
Page 221: ...221 ...
Page 225: ...225 ...
Page 229: ...229 ...
Page 237: ...237 Servicing the Fuel System ...
Page 254: ...254 ...
Page 255: ...255 LPG Parts Diagram ...
Page 256: ...256 THROTTLE BODY ASSEMBLY ...
Page 258: ...258 FUEL RAIL INJECTORS ...
Page 260: ...260 REGULATOR ASSEMBLY ...
Page 262: ...262 HOSE ASSEMBLIES COOLANT VACUUM FUEL ...
Page 264: ...264 THERMOSTAT HOUSING ...
Page 266: ...266 ENGINE CONTROL MODULE ...
Page 267: ...267 ENGINE CONTROL MODULE Item Description Qty IMPCO Part Number 1 ECM Liugong 1 A11 173 ...
Page 268: ...268 SENSORS 4 1 3 6 5 2 7 ...
Page 270: ...270 DISTRIBUTOR ...
Page 272: ...272 FUSE BOX BRACKET ...
Page 274: ...274 IGNITION COIL ...
Page 275: ...275 IGNITION COIL Item Description Qty Part Number 1 Coil Ignition 1 7245530 ...
Page 276: ...276 MANIFOLDS ...
Page 278: ...278 WIRE HARNESS FUSES FUSE BOX COVER Fuse Box Layout 4 ...
Page 280: ...280 PCV VENT VALVE ...
Page 282: ...282 MISCELLANEOUS ENGINE ...
Page 284: ...284 ALTERNATOR ...
Page 286: ...286 STARTER ...
Page 291: ...291 ...
Page 292: ...292 3 0L UPPER ...
Page 294: ...294 3 0L LOWER ...
Page 298: ...298 ...
Page 299: ...299 Labor Time Guide ...
Page 317: ...317 Definitions ...
Page 322: ...322 ...
Page 323: ...323 Appendix ...
Page 327: ...327 DTC SPN FMI Chart ...