
When Monitored:
Any time the engine is running, and the adaptive numerator has been successfully updated.
Set Condition:
When more than a 1% misfire rate is measured during two trips, or with a 6% to 30% misfire rate during one
trip.
Possible Causes
(K342) ASD RELAY OUTPUT CIRCUIT
(K28) INJECTOR CONTROL CIRCUIT
(K18) COIL CONTROL CIRCUIT
IGNITION WIRE
SPARK PLUG
IGNITION COIL
FUEL PUMP INLET STRAINER PLUGGED
RESTRICTED FUEL SUPPLY LINE
FUEL PUMP MODULE
FUEL PRESSURE LEAK DOWN
FUEL INJECTOR
ENGINE MECHANICAL
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.CYLINDER MIS-FIRE CONDITION ACTIVE
Engine running.
Observe the WHICH CYLINDER IS MISFIRING screen for at least one minute on the scan tool.
Isthereamisfirepresentatthistime?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.VISUAL INSPECTION
NOTE: Anything that affects the speed of the crankshaft can cause a misfireDTC.
NOTE: When a Misfire is detected for a particular cylinder, the PCM will shut down that cylinders Injector
Control circuit.
- Visually inspect the engine for any of the following conditions.
- Worn serpentine belt
- Binding Engine-Driven accessories: A/C Compressor, P/S Pump, Water pump.
- Misalignment of the Water pump, P/S Pump and A/C Compressor pulleys
- Corroded PCM power and ground circuits.
- Improper CKP, CMP, MAP, and TP Sensor mounting
- Poor connector/terminal to component connection. i.e., CKP sensor, Fuel Injector, Ign coil, etc.
- Vacuum leaks
- Restricted Air Induction system or Exhaust system.

When Monitored:
Any time the engine is running, and the adaptive numerator has been successfully updated.
Set Condition:
When more than a 1% misfire rate is measured during two trips, or with a 6% to 30% misfire rate during one
trip.
Possible Causes
(K342) ASD RELAY OUTPUT CIRCUIT
(K115) INJECTOR CONTROL CIRCUIT
(K18) COIL CONTROL CIRCUIT
IGNITION WIRE
SPARK PLUG
IGNITION COIL
FUEL PUMP INLET STRAINER PLUGGED
RESTRICTED FUEL SUPPLY LINE
FUEL PUMP MODULE
FUEL PRESSURE LEAK DOWN
FUEL INJECTOR
ENGINE MECHANICAL
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.CYLINDER MIS-FIRE CONDITION ACTIVE
Engine running.
Observe the WHICH CYLINDER IS MISFIRING screen for at least one minute on the scan tool.
Isthereamisfirepresentatthistime?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.VISUAL INSPECTION
NOTE: Anything that affects the speed of the crankshaft can cause a misfireDTC.
NOTE: When a Misfire is detected for a particular cylinder, the PCM will shut down that cylinders Injector
Control circuit.
- Visually inspect the engine for any of the following conditions.
- Worn serpentine belt
- Binding Engine-Driven accessories: A/C Compressor, P/S Pump, Water pump.
- Misalignment of the Water pump, P/S Pump and A/C Compressor pulleys
- Corroded PCM power and ground circuits.
- Improper CKP, CMP, MAP, and TP Sensor mounting
- Poor connector/terminal to component connection. i.e., CKP sensor, Fuel Injector, Ign coil, etc.
- Vacuum leaks
- Restricted Air Induction system or Exhaust system.

When Monitored:
Any time the engine is running, and the adaptive numerator has been successfully updated.
Set Condition:
When more than a 1% misfire rate is measured during two trips, or with a 6% to 30% misfire rate during one
trip.
Possible Causes
(K342) ASD RELAY OUTPUT CIRCUIT
(K116) INJECTOR CONTROL CIRCUIT
(K17) COIL CONTROL CIRCUIT
IGNITION WIRE
SPARK PLUG
IGNITION COIL
FUEL PUMP INLET STRAINER PLUGGED
RESTRICTED FUEL SUPPLY LINE
FUEL PUMP MODULE
FUEL PRESSURE LEAK DOWN
FUEL INJECTOR
ENGINE MECHANICAL
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.CYLINDER MIS-FIRE CONDITION ACTIVE
Engine running.
Observe the WHICH CYLINDER IS MISFIRING screen for at least one minute on the scan tool.
Isthereamisfirepresentatthistime?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.VISUAL INSPECTION
NOTE: Anything that affects the speed of the crankshaft can cause a misfireDTC.
NOTE: When a Misfire is detected for a particular cylinder, the PCM will shut down that cylinders Injector
Control circuit.
- Visually inspect the engine for any of the following conditions.
- Worn serpentine belt
- Binding Engine-Driven accessories: A/C Compressor, P/S Pump, Water pump.
- Misalignment of the Water pump, P/S Pump and A/C Compressor pulleys
- Corroded PCM power and ground circuits.
- Improper CKP, CMP, MAP, and TP Sensor mounting
- Poor connector/terminal to component connection. i.e., CKP sensor, Fuel Injector, Ign coil, etc.
- Vacuum leaks
- Restricted Air Induction system or Exhaust system.

12.(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the (F855) 5-volt Supply
circuit in the CKP Sensor harness connector.
Istheresistancebelow100ohms?
Ye s>>
Repair the short to ground in the (F855) 5-volt Supply cir-
cuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 13
13.PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.
Were there any problems found?
Ye s>>
Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
14.ERRATIC CKP SENSOR SIGNAL
Turn the ignition off.
With a lab scope probe and the Miller special tool #6801, backprobe the (K24) CKP Signal circuit in the CKP har-
ness connector.
WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands
near the pulleys, belts, or fan. Do notwear loose clothing. Failure to follow these instructions can result in
personal injury or death.
Ignition on, engine not running.
Wiggle the related wire harness and lightly tap on the Crank Position Sensor.
Observe the lab scope screen.
Look for any pulses generated by the CKP Sensor.
Allow the engine to idle.
Observe the lab scope screen.
Did the CKP Sensor generate any erratic pulses?
Ye s>>
Inspect the related wire harness and replace the Crankshaft Position Sensor if no wiring problems were
found.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 15

15.ERRATIC CMP SIGNAL
Turn the ignition off.
With a lab scope probe and the Miller special tool #6801, backprobe the (K44) CMP Signal circuit in the CMP
harness connector.
WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands
near the pulleys, belts, or fan. Do notwear loose clothing. Failure to follow these instructions can result in
personal injury or death.
Ignition on, engine not running.
Wiggle the related wire harness and lightly tap on the Cam Position Sensor.
Observe the lab scope screen.
Look for any pulses generated by the CMP Sensor.
Allow the engine to idle.
Observe the lab scope screen.
Did the CMP Sensor generate any pulses?
Ye s>>
Inspect the related wire harness and replace the Camshaft Position Sensorif no wiring problems were
found.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Test complete, the conditions that set this DTC are not present at this time.

12.(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the (F855) 5-volt Supply
circuit in the CMP Sensor harness connector.
Istheresistancebelow100ohms?
Ye s>>
Repair the short to ground in the (F855) 5-volt Supply cir-
cuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 13
13.PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.
Were there any problems found?
Ye s>>
Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
14.ERRATIC CMP SIGNAL
With a lab scope probe and the Miller special tool #6801, back probe the (K44) CMP Signal circuit in the CMP
harness connector.
WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands
near the pulleys, belts, or fan. Do notwear loose clothing. Failure to follow these instructions can result in
personal injury or death.
Ignition on, engine not running.
Wiggle the related wire harness and lightly tap the Camshaft Position Sensor.
Observe the lab scope screen.
Allow the engine to idle.
Observe the lab scope screen.
Did the CMP Sensor generate any erratic pulses?
Ye s>>
Replace the Camshaft Position Sensor.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 15

15.ERRATIC CKP SIGNAL
Turn the ignition off.
With a lab scope probe and the Miller special tool #6801, backprobe the (K24) CKP Signal circuit in the CKP har-
ness connector.
WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands
near the pulleys, belts, or fan. Do notwear loose clothing. Failure to follow these instructions can result in
personal injury or death.
Ignition on, engine not running.
Wiggle the related wire harness and lightly tap on the Crankshaft PositionSensor.
Observe the lab scope screen.
Allow the engine to idle.
Observe the lab scope screen.
Did the CKP Sensor generate any erratic pulses?
Ye s>>
Replace the Crankshaft Position Sensor.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Test complete, the conditions that set this DTC are not present at this time

3.(K342) ASD CONTROL OUTPUT CIRCUIT
Turn the ignition off
Connect the C2 TIPM harness connector.
Ignition on, engine not running.
Back probe the C10 TIPM harness connector at the (K342) ASD Control Output circuit terminal and measure the
voltage on the (K342) ASD Control Output circuit.
Is the voltage above 10 volts?
Ye s>>
Go To 4
No>>
Go To 7
4.(K342) ASD CONTROL OUTPUT CIRCUIT VOLTAGE DROP TO THE FUEL INJECTORS
Turn the ignition off.
With a voltmeter, use Negative lead of the voltmeter along with terminal probe tool #6801, backprobe the (K342)
ASD Control Output circuit at a Fuel Injector harness connector.
With the Positive lead of the voltmeter along with terminal probe tool #6801, back probe the (K342) ASD Control
Output circuit at the C10 TIPM harness connector.
Start the engine and allow it to idle.
WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands
near the pulleys, belts, or fan. Do notwear loose clothing. Failure to follow these instructions can result in
personal injury or death.
Measure the voltage of the (K342) ASD Control Output circuit.
NOTE: Perform the test at every fuel injector.
Is the voltage above 0.001 of a volt (1.0mV) for any of the Fuel Injector ASD Control Output circuits?
Ye s>>
Repair the excessive resistance in the (K342) ASD Control Output circuit to the appropriate Fuel Injec-
tor.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 5
5.(K342) ASD CONTROL OUTPUT CIRCUIT VOLTAGE DRIP TO THE IGNITION COILS
Turn the Ignition off.
With a voltmeter, use Negative lead of the voltmeter along with terminal probe tool #6801, backprobe the (K342)
ASD Control Output circuit at a Ignition Coil harness connector.
With the Positive lead of the voltmeter along with terminal probe tool #6801, back probe the (K342) ASD Control
Output circuit at the C10 TIPM harness connector.
Start the engine and allow it to idle.
WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands
near the pulleys, belts, or fan. Do notwear loose clothing. Failure to follow these instructions can result in
personal injury or death.
Measure the voltage of the (K342) ASD Control Output circuit.
NOTE: Perform the test at every Ignition Coil.
Is the voltage above 0.001 of a volt (1.0mV) for any of the Ignition Coil ASD Control Output circuits?
Ye s>>
Repair the excessive resistance in the (K342) ASD Control Output circuit to the appropriate Ignition Coil.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 6