P2311
SYMPTOM
P2311 IGNITION COIL 4 SECONDARY CIRCUIT INSUFFICIENT IONIZATION
WHEN MONITORED
Engine running and battery voltage greater than 10 volts.
SET CONDITION
If PCM detects that the secondary ignition burn time is incorrect, to short, or not present, an error is detected. One Trip Fault. Three good trips to turn off the MIL.
POSSIBLE CAUSES
- (A955), (K342) ASD RELAY OUTPUT CIRCUIT
- (K15) COIL CONTROL NO.4 CIRCUIT OPEN
- (K15) COIL CONTROL NO.4 CIRCUIT SHORTED TO GROUND
- COIL ON PLUG
- PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Scan Tool Testing and Procedures
DIAGNOSTIC TEST
1. ACTIVE DTC
Ignition on, engine not running.
With a scan tool, read DTCs.
Is the DTC active at this time?
Yes>> Go To 2
No>> Perform (NGC) POWERTRAIN VERIFICATION TEST VER-5. Powertrain Verification Test - Ver 5
2. (A955), (K342) ASD RELAY OUTPUT CIRCUIT
Note: The circuit id (K342) is used with the 5.7L engines and the (A955) id is used with the 3.7L and 4.7L engines.
Turn the ignition off.
Disconnect the Coil on Plug harness connector. Ignition on, engine not running.
With a scan tool, actuate the ASD Relay.
Using a 12-volt test light connected to ground, probe the (A955), (K342) ASD Relay Output circuit in the Coil on Plug harness connector.
Does the test light illuminate brightly?
Yes>> Go To 3
No>> Repair the open or short to ground in the (A955), (K342) ASD Relay Output circuit between the IPM and Coil harness connector. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-5.
Note: Stop All Actuations.
3. COIL ON PLUG RESISTANCE
Turn the ignition off.
Note: The following resistance measurement should be taken at 70°-80 °F.
Measure the resistance of the Coil on Plug.
4.7L and 3.7L Primary Ignition Coil resistance is 0.6 to 0.9 of an ohm at 77 °F (25 °C).
5.7L Primary Ignition Coil resistance is 0.558 to 0.682 of an ohm at 77 °F (25 °C).
Is the resistance within the given specification for the Ignition Coil being tested?
Yes>> Go To 4
No>> Replace the Coil on plug. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-5.
4. IGNITION COIL
Using a 12-volt test light connected to a 12-volt source, probe the (K15) Coil Control No.4 circuit. Crank the engine for 5 seconds while observing the test light.
What is the state of the test light while cranking the engine?
Brightly blinking.
Replace the Coil on plug. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-5.
ON constantly.
Go To 5
OFF constantly.
Go To 6
5. (K15) COIL CONTROL NO.4 CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Disconnect the C2/B PCM harness connector.
Measure the resistance between ground and the (K15) Coil Control No.4 circuit in the Coil on Plug harness connector.
Is the resistance below 100 ohms?
Yes>> Repair the short to ground in the (K15) Coil Control No.4 circuit. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-5.
No>> Go To 7
6. (K15) COIL CONTROL NO.4 CIRCUIT OPEN
Turn the ignition off.
Disconnect the C2/B PCM harness connector.
CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool # 8815 to perform diagnosis.
Measure the resistance of the (K15) Coil Control No.4 circuit from the Coil on Plug harness connector to the appropriate terminal of special tool # 8815.
Is the resistance below 5.0 ohms?
Yes>> Go To 7
No>> Repair the open in the (K15) Coil Control No.4 circuit. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-5.
7. 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?
Yes>> Repair as necessary. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-5.
No>> Replace and program the Powertrain Control Module per Service Information. Perform (NGC) POWERTRAIN VERIFICATION TEST VER-5.