Download DTC P1351 Ignition Coil Control Circuit High Voltage

Trouble Code: P1351 (5.7L V8 VIN R
Auto)
ICM Ignition Control Circuit High Input
Print this code data
Number of Trips to Set Code: 1
OBD II Monitor Type: CCM Details
Indicators: MIL Details
 CCM Details
 MIL Details
Trouble Code Conditions:
Engine started, engine speed less than 250 rpm, ignition control "on", system
voltage over 4.90v, and the PCM detected the ignition control circuit indicated
over 4.90v during the test.
Possible Causes:
 ICM control circuit is open, shorted to ground or shorted to
B+
 ICM power circuit is open (check power from the ECM1 fuse)
 ICM is damaged or has failed
 PCM has failed
1997 Chevrolet K2500 - Powertrain - Engine Controls - 5.0L, 5.7L, and
7.4L - DTC P1351 Ignition Coil Control Circuit High Voltage
PATH: Diagnostics > Diagnostic Routines > Powertrain > Engine Controls - 5.0L,
5.7L, and 7.4L > DTC P1351 Ignition Coil Control Circuit High Voltage
DTC P1351 Ignition Coil Control Circuit High Voltage
NOTE
Applicable vehicles:
 Chevy Pickup, GMC Pickup, Suburban, Tahoe, Yukon (VIN C/K)
 NPR/NQR
DTC P1351 Ignition Coil Control Circuit High Voltage
Click to Enlarge
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.
Action Taken When The DTC Sets
 The VCM turns the MIL ON when this DTC is reported and
one failure has occurred.
 The VCM records the operating conditions at the time the
Diagnostic Fails. Freeze Frame and Failure Records store this
information.
Conditions for Clearing the MIL/DTC
The VCM turns OFF the MIL after 3 consecutive driving trips without a fault
condition present. A history DTC will clear if no fault conditions have been
detected for 40 warm-up cycles (the coolant temperature has risen 22°C (40°F)
from the start-up coolant temperature and the engine coolant temperature
exceeds 71°C (160°F) during that same ignition cycle) or the scan tool clearing
feature has been used.
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.
Test Description
The numbers below refer to the step numbers in the diagnostic table.
2. This determines if the DTC is an intermittent.
3. This check determines if the IC signal from the VCM is available
at the ignition coil driver.
4. The remaining tests begin to check that the coil driver circuitry is
OK.
Step
Action
Value(s)
Yes
No
Go to Step
2
Go to
Powertrain
On Board
Diagnostic
(OBD)
System
Check
WARNING
1
Important: Before clearing
DTCs, use the scan tool in order
to record the freeze frame and
the failure records for reference
--
Step
Action
Value(s)
Yes
No
Go to Step
3
Go to
Diagnostic
Aids
because the Clear Info function
will lose the data.
Was the Powertrain On-Board
Diagnostic (OBD) System Check
performed?
2
3
4
1. Clear the DTCs.
2. Disconnect the
injector connector.
3. Crank the engine for
30 seconds.
Does DTC P1351 set?
--
1. Turn OFF the ignition.
2. Reconnect the injector
connector.
3. Disconnect the
ignition coil module
connector.
4. Probe the ignition coil
module connector
terminal B with a
voltmeter to ground.
5. With the voltmeter on
the AC scale, crank
the engine.
6. Monitor the voltage
reading.
Is the voltage reading within the
specified value?
1-4V
1. Turn OFF the ignition.
2. Disconnect the VCM
gray harness
connector.
3. Check the resistance
between the VCM
Ignition Control and
the ignition coil
module connector
terminal B.
Is the resistance less than the
10 ?
Go to Step
9
Go to Step 4
Go to Step
6
Go to Step 5
Step
Action
specified value?
Value(s)
Repair the open IC circuit between
the VCM and the ignition coil
module. Refer to Wiring Repairs in
Engine Electrical.
Is the action complete?
--
6
Check for a faulty VCM
connection.
Was a problem found?
--
7
Repair the faulty VCM connection.
Refer to Wiring Repairs in Engine
Electrical.
Is the action complete?
--
5
Yes
No
Go to Step
16
--
Go to Step
7
Go to Step 8
Go to Step
16
--
Go to Step
16
--
Replace the VCM.
WARNING
8
Important: If the VCM is faulty,
reprogram the VCM. Refer to
VCM
Replacement/Programming .
--
Is the replacement complete?
9
10
11
1. Turn OFF the ignition.
2. Connect a test lamp to
B+.
3. Probe the ignition coil
module harness
connector terminal C.
Is the test lamp on?
--
Repair the open ignition coil
module ground circuit. Refer to
Wiring Repairs in Engine
Electrical.
Is the repair complete?
--
1. Turn ON the ignition.
2. Connect a test lamp to
a ground.
3. Probe the ignition coil
Go to Step
11
Go to Step 10
Go to Step
16
--
--
Go to Step
13
Go to Step 12
Step
Action
module harness
connector terminals D
and A.
Is the test lamp on both terminals?
Value(s)
Repair the faulty ignition coil
module feed circuit. Refer to
Wiring Repairs in Engine
Electrical.
Is the repair complete?
--
13
Check for a faulty ignition coil
module connection.
Was a problem found?
--
14
Replace the ignition coil module.
Refer to Ignition Coil Driver
Module.
Is the action complete?
--
Repair the ignition coil module
connection. Refer to Wiring
Repairs in Engine Electrical.
Is the action complete?
--
1. Using the scan tool,
select the DTC and the
Clear Info.
2. Start the Engine.
3. Idle at the normal
operating temperature.
4. Select the DTC and
the Specific.
5. Enter the DTC number
which was set.
6. Operate the vehicle
within the conditions
for setting this DTC as
specified in the
supporting text.
Does the scan tool indicate that this
diagnostic ran and passed?
--
Using the scan tool, select the
Capture Info and the Review Info.
--
12
15
16
17
Yes
No
Go to Step
16
--
Go to Step
15
Go to Step 14
Go to Step
16
--
Go to Step
16
--
Go to Step
17
Go to Step 2
Go to The
Applicable
System OK
Step
Action
Are any DTCs displayed that have
not been diagnosed?
Value(s)
Yes
DTC Table
No