Circuit Description
A Crankshaft Position (CKP) sensor determines the engine crankshaft position. The sensor is mounted and protrudes into the rear of the engine block. The sensor is near a slotted wheel on the crankshaft. The rotation of the slotted wheel causes a magnetic flux change in the sensor. This produces a voltage signal from the electronic Ignition Control Module (ICM). The signal creates the reference pulses needed by the Powertrain Control Module (PCM). These signals trigger the correct ignition coil to fire, at the correct time.
The ignition system on this engine uses an individual ignition coil/module
for each cylinder. The PCM controls the ignition system operation. There are
eight Ignition Control (IC) circuits, one per cylinder, that connect the PCM
and the ignition coil/modules. Each ignition coil/module has a power feed,
a chassis ground circuit, and a reference low circuit. The PCM causes a spark
to occur by grounding the IC circuit, which signals the ignition module to
trigger the ignition coil and fire the spark plug. The PCM controls the sequencing
and timing. For ignition control circuit schematics, refer to
Cell 20: Ignition Coil/Module Cylinders #1 & #3
or
Cell 20: Ignition Coil/Module Cylinders #2 & #4
.
Diagnostic Aids
The following may cause an intermittent:
| • | Check for poor connections. Check for adequate terminal tension. Refer to Body and Accessories/Wiring for proper procedure. |
| • | Corrosion |
| • | Mis-routed harness |
| • | Rubbed through wire insulation |
| • | Broken wire inside the insulation |
Using Freeze Frame and/or Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can also help determine how many ignition cycles the diagnostic reported a pass and/or a fail. Operate vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature etc.) that you observed. This will isolate when the DTC failed. For an intermittent condition, refer to Symptoms .
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
Monitoring the misfire current counters determines if a fault is present.
-
A good indication that the fuse is open is all the misfire current counters are incrementing on one side of the engine. Inspect the ignition feed circuit for a grounded circuit.
-
If the fuse is open and no problem can be found with the ignition coil/module circuits, inspect the injector circuits for being grounded. The INJR1 fuse and INJR2 fuse feeds the ignition coil/module circuits and injector circuits.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||
2 | Are DTCs P0335, P0336, P0351 - P0358 set? | -- | Go to Applicable DTC Table | |
3 |
Important: This table assumes that there are no injector circuit malfunctions or mechanical malfunctions. If you were not sent here from DTC P0300, refer to DTC P0300 before proceeding with this table.
Are any of the Misfire Cur. counters incrementing? | -- | Intermittent Condition. Go to Diagnostic Aids | |
4 | Are the misfire current counters incrementing for all cylinders on one bank of the engine? | -- | ||
5 |
Does the test lamp illuminate? | -- | ||
6 | Using a test lamp J 35616-200 probe the ignition feed circuit at the ignition coil/module electrical 8-way connector to the ignition coil/module ground circuit. Does the test lamp illuminate? | -- | ||
7 | Using a test lamp J 35616-200 probe the ignition feed circuit at the ignition coil/module electrical 8-way connector to the ignition coil/module reference low circuit. Does the test lamp illuminate? | -- | ||
8 |
Did you find a problem and correct it? | -- | System OK | |
9 | Repair the open in the ignition feed circuit between the fuse block and the splice. Refer to Body and Accessories/Wiring Systems for procedures. Is the action complete? | -- | System OK | -- |
10 |
Does the test lamp illuminate? | -- | ||
11 | Repair the open circuit between the splice and the ignition coil/module connector. Refer to Body and Accessories/Wiring Systems for procedures. Is the action complete? | -- | System OK | -- |
12 | Repair the open ignition feed circuit between the fuse block (open fuse) and splice. Refer to Body and Accessories/Wiring Systems for procedures. Is the action complete? | -- | System OK | -- |
13 |
Does the test lamp illuminate? | -- | ||
14 |
Did you find a problem and correct it? | -- | System OK | |
15 | Repair the open ground circuit between the main 8-way connector and the ignition coil/module connector. Refer to Body and Accessories/Wiring Systems for procedures. Is the action complete? | -- | System OK | -- |
16 | Repair the open ground circuit between the ground and the main 8-way connector. Refer to Body and Accessories/Wiring Systems for procedures. Is the action complete? | -- | System OK | -- |
17 |
Does the test lamp illuminate? | -- | ||
18 |
Did you find a problem and correct it? | -- | System OK | |
19 | Repair the open reference low circuit between the main 8-way connector and the ignition coil/module connector. Refer to Body and Accessories/Wiring Systems for procedures. Is the action complete? | -- | System OK | -- |
20 | Repair the open reference low circuit between the PCM and the splice. Refer to Body and Accessories/Wiring Systems for procedures. Is the action complete? | -- | System OK | -- |
21 |
Did you find a problem and correct it? | -- | System OK | |
22 | Replace ignition coil/module. Is the action complete? | -- | System OK
| -- |
