Circuit Description
This engine is equipped with a distributor-less ignition system called the electronic ignition (EI) system. The primary circuit of the EI system consists of 2 separate ignition coils, an electronic ignition control module (ICM) and a crankshaft position (CKP) sensor as well as the related connecting wires and the ignition control (IC) portion of the powertrain control module (PCM). Each secondary circuit consists of the secondary winding of the coil, spark plug wires, and the spark plugs.
Important: The camshaft position (CMP) sensor is only used for a misfire detection and is not part of the ignition system.
Diagnostic Aids
Test/Inspect for the following conditions:
| • | Collapsed air intake duct. |
| • | Restricted air filter element. Refer to Air Cleaner Element Replacement . |
| • | A TP sensor that reads too high or skewed may cause an incorrect fueling condition. |
| • | A throttle position (TP) sensor binding or sticking in wide open position. |
| • | A TP sensor shorted or open. |
| • | Fuel contamination |
| • | Out of fuel |
| • | Restricted exhaust system. Refer to Restricted Exhaust in Engine Exhaust. |
| • | Low compression -- refer to Engine Compression Test in Engine Mechanical. |
| • | A cold engine that has not been started should display engine coolant temperature (ECT) and intake air temperature (IAT) temperatures that are relatively close to each other. |
| • | A skewed manifold absolute pressure (MAP) sensor. The MAP sensor value should change when cranking the engine. Compare any questionable barometer readings with that of a known good vehicle. |
Check for intermittent conditions. Refer to Intermittent Conditions .
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Values | Yes | No | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |||||||||
2 |
Does the scan tool display DTCs P0336, P0601, P0602, P1621, P1626, P1631, or P1632. | -- | Go to Step 3 | |||||||||
With the scan tool, observe the CKP activity counter while cranking the engine. Does the CKP activity counter increment while cranking the engine? | -- | Go to Step 4 | ||||||||||
4 |
Important: Ensure the fuses below are not open, before proceeding with this test.
Does the test lamp illuminate on both sides of all the fuses? | -- | Go to Step 5 | Go to Testing for Short to Ground in Wiring Systems | ||||||||
5 | With the scan tool, command the fuel pump ON. Does the fuel pump run? | -- | Go to Step 6 | |||||||||
6 |
Does the fuel pressure read within the specified value? | 248-325 kPa (41-47 psi) | Go to Step 7 | Go to Fuel System Diagnosis | ||||||||
7 |
Does the test lamp blink while cranking the engine? | -- | Go to Step 8 | |||||||||
8 |
Did spark occur on all cylinders? | -- | Go to Step 9 | |||||||||
9 |
Did you find and correct the condition? | -- | Go to Step 10 | Go to Diagnostic Aids | ||||||||
10 | Attempt to start the engine. Does the engine start and continue to run? | -- | Go to Step 2 |
