I need help,cant get truck to start, no spark
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#25
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From: Arlington (DFW), Texas
Bought a volt meter and test the wires at the ignition module and coil. They are getting 11.9 volts, they should be getting less than 4.5 volts. I traced both the wires getting too much voltage and they go into the fuse panel under the hood. Any ideas how those two wires are getting that much voltage? What would make them change voltage like that?
#27
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13 Second Truck Club
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From: Arlington (DFW), Texas
With five other links saying it.....
DTC P1351 Ignition Coil Control Circuit High Voltage
Circuit Description
The enhanced ignition system uses the crank sensor in order to provide the timing input to the VCM. The VCM uses this reference pulse in order to determine the individual ignition spark timing for each cylinder.
Once the VCM calculates the ignition timing, the ignition coil module on the IC circuit receives the timing signal. Each timing pulse received by the ignition coil module on the IC circuit triggers the coil module in order to operate the ignition coil. The secondary ignition voltage is induced, and then the secondary ignition voltage is sent to the distributor for distribution to each spark plug. This DTC is a type A DTC.
The IC signal voltage ranges from about 0.5 volt to 4.5 volts.
Conditions for Setting the DTC
EST enabled, and the engine speed is less than 250 RPM.
Diagnostic Aids
A poor connection, a rubbed through wire in the insulation, or a wire broken inside the insulation will cause an intermittent.
Check for the following conditions:
Poor connection
Damaged harness: Inspect the VCM harness connectors for the following conditions:
Backed out terminal C3 pin 9
Improper mating
Broken locks
Improperly formed or damaged terminals
A poor terminal to wire connection and
Damage to the harness.
Intermittent test - If the connections and the harness check OK, monitor a digital voltmeter connected between VCM connector C3 pin 9 and C4 pin 18 while moving related connectors and wiring harness. If the failure is induced, the voltage reading will change. This may help to isolate the location of the malfunction.
DTC P1351 Ignition Coil Control Circuit High Voltage
Circuit Description
The enhanced ignition system uses the crank sensor in order to provide the timing input to the VCM. The VCM uses this reference pulse in order to determine the individual ignition spark timing for each cylinder.
Once the VCM calculates the ignition timing, the ignition coil module on the IC circuit receives the timing signal. Each timing pulse received by the ignition coil module on the IC circuit triggers the coil module in order to operate the ignition coil. The secondary ignition voltage is induced, and then the secondary ignition voltage is sent to the distributor for distribution to each spark plug. This DTC is a type A DTC.
The IC signal voltage ranges from about 0.5 volt to 4.5 volts.
Conditions for Setting the DTC
EST enabled, and the engine speed is less than 250 RPM.
Diagnostic Aids
A poor connection, a rubbed through wire in the insulation, or a wire broken inside the insulation will cause an intermittent.
Check for the following conditions:
Poor connection
Damaged harness: Inspect the VCM harness connectors for the following conditions:
Backed out terminal C3 pin 9
Improper mating
Broken locks
Improperly formed or damaged terminals
A poor terminal to wire connection and
Damage to the harness.
Intermittent test - If the connections and the harness check OK, monitor a digital voltmeter connected between VCM connector C3 pin 9 and C4 pin 18 while moving related connectors and wiring harness. If the failure is induced, the voltage reading will change. This may help to isolate the location of the malfunction.
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InsaneDomestics
Tuning, Diagnostics, Electronics, and Wiring
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Jul 27, 2015 02:42 PM




