F1976 Force SOCKET HD SCREW W/WASHER, 10 - 24 X 1/2

Table 1
Diagnostic Codes Table
Code Conditions which Generate this Code System Response
301-5 Ignition Transformer Primary #1 : Current Below Normal
302-5 Ignition Transformer Primary #2 : Current Below Normal
303-5 Ignition Transformer Primary #3 : Current Below Normal
304-5 Ignition Transformer Primary #4 : Current Below Normal
305-5 Ignition Transformer Primary #5 : Current Below Normal
306-5 Ignition Transformer Primary #6 : Current Below Normal
307-5 Ignition Transformer Primary #7 : Current Below Normal
308-5 Ignition Transformer Primary #8 : Current Below Normal
309-5 Ignition Transformer Primary #9 : Current Below Normal
310-5 Ignition Transformer Primary #10 : Current Below Normal
311-5 Ignition Transformer Primary #11 : Current Below Normal
312-5 Ignition Transformer Primary #12 : Current Below Normal
313-5 Ignition Transformer Primary #13 : Current Below Normal
314-5 Ignition Transformer Primary #14 : Current Below Normal
315-5 Ignition Transformer Primary #15 : Current Below Normal
316-5 Ignition Transformer Primary #16 : Current Below Normal With the engine cranking, the Electronic Control Module (ECM) detects a low current flow in the primary circuit for the ignition transformer. The code is logged.
The alarm output is activated.
Table 2
Diagnostic Codes Table
Code Conditions which Generate this Code System Response
301-6 Ignition Transformer Primary #1 : Current Above Normal
302-6 Ignition Transformer Primary #2 : Current Above Normal
303-6 Ignition Transformer Primary #3 : Current Above Normal
304-6 Ignition Transformer Primary #4 : Current Above Normal
305-6 Ignition Transformer Primary #5 : Current Above Normal
306-6 Ignition Transformer Primary #6 : Current Above Normal
307-6 Ignition Transformer Primary #7 : Current Above Normal
308-6 Ignition Transformer Primary #8 : Current Above Normal
309-6 Ignition Transformer Primary #9 : Current Above Normal
310-6 Ignition Transformer Primary #10 : Current Above Normal
311-6 Ignition Transformer Primary #11 : Current Above Normal
312-6 Ignition Transformer Primary #12 : Current Above Normal
313-6 Ignition Transformer Primary #13 : Current Above Normal
314-6 Ignition Transformer Primary #14 : Current Above Normal
315-6 Ignition Transformer Primary #15 : Current Above Normal
316-6 Ignition Transformer Primary #16 : Current Above Normal With the engine cranking, the ECM detects an excessive current flow in the primary circuit for the ignition transformer. The code is logged.
The alarm output is activated. The ECM has internal circuit drivers for the transformers. The circuit drivers send a signal of +108 volts to the high side of the ignition transformers' primary circuits. The transformers deliver high voltage (8000 to 37,000 volts) to the spark plugs. The ignition wiring is continuous from the ECM P2 connector to the connectors for the transformers. The ignition wiring is routed through a rail on the side of the engine.A single problem with a primary circuit will generate one diagnostic code or multiple codes.Circuit Driver's SideInternally, the ECM has an individual circuit driver for each transformer. These circuits are wired individually from the ECM J2/P2 connectors to each transformer. If any cylinder's circuit driver's side has a problem, only that cylinder is affected.Return SideThe current for the return to ground is limited to a single transformer. This means that a return short circuit to the −Battery side or an open circuit will affect only one cylinder.The ECM has internal returns for the transformers. These returns consist of groups of terminals that are connected via diodes inside the ECM. This means that a return short circuit to the +Battery side will simultaneously affect all of the cylinders that are grouped.RecommendationIf multiple diagnostic codes are active for the primary ignition, troubleshoot the affected circuits one at a time in order to find the root cause.For the combinations of cylinders that can be affected in 6 cylinder engines, refer to Table 3. Illustration 1 is a schematic that includes the internal circuitry for a 6 cylinder engine's ECM.
Table 3
6 Cylinder Engine
Diagnostic Conditions and the Combinations of Cylinders that are Affected
Condition Cylinders
Circuit driver's side open Only one cylinder is affected.
Circuit driver's side
Short to +Battery
Circuit driver's side
Short to ground
Return side open
Return side short to ground
Return side
Short to +Battery 1, 2, and 3
4, 5, and 6
Illustration 1 g01438037
Schematic of a 6 cylinder engine's ignition system
Illustration 2 g01438047
Harness side of the ECM P2 connector (G3606 Engine)
(P2-1) Number 1 transformer's circuit driver
(P2-2) Number 1 transformer's return
(P2-24) Number 2 transformer's circuit driver
(P2-25) Number 2 transformer's return
(P2-14) Number 3 transformer's circuit driver
(P2-15) Number 3 transformer's return
(P2-26) Number 4 transformer's circuit driver
(P2-27) Number 4 transformer's return
(P2-3) Number 5 transformer's circuit driver
(P2-4) Number 5 transformer's return
(P2-16) Number 6 transformer's circuit driver
(P2-17) Number 6 transformer's return For the combinations of cylinders that can be affected in 8 cylinder engines, refer to Table 4. Illustration 3 is a schematic that includes the internal circuitry for an 8 cylinder engine's ECM.
Table 4
8 Cylinder Engine
Diagnostic Conditions and the Combinations of Cylinders that are Affected
Condition Cylinders
Circuit driver's side open Only one cylinder is affected.
Circuit driver's side
Short to +Battery
Circuit driver's side
Short to ground
Return side open
Return side short to ground
Return side
Short to +Battery 1, 2, 7, and 8
3, 4, 5, and 6
Illustration 3