This engine is equipped with a distributorless 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.
An intermittent DTC can also be the result of a defective reluctor wheel. Remove the crankshaft sensor and inspect the reluctor wheel through the crankshaft sensor mount hole. Check the porosity and the condition of the reluctor wheel.
Whenever the DTC is an intermittent, refer to the Driveability Symptom Tables.
Perform the fuel Injector Balance Test. Refer to Fuel Injector Balance Test .
Number(s) below refer to the step number(s) on the Diagnostic Table.
The Powertrain OBD System Check prompts the technician to complete some basic checks and store the freeze frame and failure records data on the scan tool if applicable. This creates an electronic copy of the data taken when the malfunction occurred. The information is then stored in the scan tool for later reference.
Diagnosis of the DTCs that may be set could lead to the cause of the Cranks But Will Not Run condition.
The PCM grounds will only cause a problem if all the grounds are not making a good connection. If a PCM ground problem is suspected, the most probable place to check is where all the grounds meet at the engine block.
Locate and repair any shorts that may have caused the fuse to open before replacing the fuse.
A TP sensor that reads too high may cause an incorrect fueling condition.
An engine that has not been started should display ECT and IAT temperatures that are relatively close to each other. During the warmer weather, the IAT readings maybe slightly higher than the ECT readings.
If the scan tool loses serial data only while cranking the engine, then the ignition switch is not sending voltage to the PCM while in the crank position.
This step looks for a normal barometer reading and a change in MAP sensor values while cranking the engine. This step verifies the MAP sensor can detect the change in the manifold pressure that occurs while cranking the engine. Compare any questionable barometer readings with readings from another vehicle.
While cranking the engine, the CKP Activity (7X reference) should increment to 255, then rollover to 0.
By testing for spark on all 4 plug wire leads using a spark tester J 26792 , each ignition coil(s) ability to produced at least 25,000 volts is verified.
The CKP sensor core is a magnet, therefore it should be magnetized.
The CKP sensor should output a voltage near 1100-1300 mV as the crankshaft turns. It is possible to trigger the ICM with a voltage as low as 200 mV. If no voltage is produced, a poor CKP sensor electrical connection or malfunctioning CKP sensor is indicated.
The test light connected to B+ simulates a reference signal to the PCM. An fuel injector test light can be installed and will blink for every other touch of the test light if the CKP Activity (7X reference) circuit, the PCM and the fuel injector driver are all functioning properly.
Notice: Do not leave the jumper wire connected to the PCM IC circuit connector for longer than 5 seconds at a time. Failure to do so may damage the ignition coil and/or the Ignition Control Module.
This step checks the ignition control circuits and the ICM.
The replacement PCM must be reprogrammed and the crankshaft position system variation procedure must be performed. Refer to the latest Techline procedures for PCM reprogramming and to the Crankshaft Position System Variation Learn for the CKP System Variation Learn Procedure.
Battery voltage should be available at the fuel injector ignition feed circuit whenever the fuel pump power feed circuit is switched ON and when the PCM is receiving ignition pulses, during engine cranking or when the engine is running. The ignition switch must be turned OFF for at least 10 seconds to assure that the PCM powers down and will then switch the fuel pump back ON for 2-3 seconds when the ignition switch is turned back ON.
The fuel pump is turned ON by the PCM for 2-3 seconds after the ignition switch is first turned ON. This step checks to see if the fuel pump and fuel pump relay are operating correctly and if the fuel pressure is within the proper range. Refer to the Fuel System Diagnosis for the fuel pressure gage installation procedure.
Step | Action | Value(s) | Yes | No | ||||
---|---|---|---|---|---|---|---|---|
Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | |||||||
Are DTCs P0601, P0602, P1621, P1626, P1631 or P1632 set? | -- | Go to the applicable DTC tables | ||||||
Inspect the PCM ground connection at the engine block. Is the ground connection OK? | -- | |||||||
4 | Inspect the F/P-INJ or IGN fuses. Are the fuses OK? | -- | ||||||
5 | Repair PCM ground connection. Refer to Wiring Repairs in Wiring Systems . Is the action complete? | -- | -- | |||||
6 |
Was it necessary to add fuel? | -- | ||||||
Is the action complete? | -- | -- | ||||||
Does the TP sensor read less than the specified value? | 1.0V | Go to DTC P0123 Throttle Position (TP) Sensor Circuit High Voltage | ||||||
Is the Engine Coolant Temperature (ECT) relatively close to the Intake Air Temperature (IAT)? | -- | Go to DTC P0118 Engine Coolant Temperature (ECT) Sensor Circuit High Voltage | ||||||
Was serial data lost while cranking the engine? | 4.0V | |||||||
Does the MAP sensor read over the specified value and then change while cranking the engine? | 4.0V | |||||||
Check to see if the CKP Activity Counter increments while cranking the engine with the scan tool. Does the CKP Activity Counter increment while cranking the engine? | -- | |||||||
13 | Repair voltage loss to the PCM from the ignition switch. Is the action complete? | -- | -- | |||||
14 |
Was a repair necessary? | -- | ||||||
15 |
Is spark observed on all of the wires? | -- | ||||||
16 |
Is the resistance reading within the specified value? | 700-1,300ohms | ||||||
17 |
Is the CKP sensor magnetic with undamaged terminals and the resistance with the specified value? | 700-1,300ohms | ||||||
Is the voltage reading greater than the specified value? | 200 mV | |||||||
19 |
Was a repair necessary? | -- | ||||||
20 |
Was a repair necessary? | -- | ||||||
Does the CKP Activity Counter increment as the test light touches B+? | -- | |||||||
22 | Repair the open or a short in the CKP sensor electrical harness. Refer to Wiring Repairs in Wiring Systems. Is the action complete? | -- | -- | |||||
23 | Replace the CKP sensor. Refer to Crankshaft Position Sensor Replacement . Is the action complete? | -- | -- | |||||
24 |
Does test light illuminate? | -- | ||||||
25 |
Was repair necessary? | -- | ||||||
26 | Repair the malfunctioning ICM ignition feed circuit. Is the action complete? | -- | -- | |||||
Notice: Do not leave the jumper wire connected to the PCM IC circuit connector for longer than 5 seconds at a time. Failure to do so may damage the ignition coil and/or the Ignition Control Module. Does a spark jump across the spark tester? | -- | |||||||
28 | Measure the resistance of the spark plug wire that the spark plug tester did not spark with a DMM. Is the resistance of the spark plug wire less than the specified value? | 30,000 ohms | ||||||
29 |
Is the secondary coil resistance within the specified value? | 5-8K ohms | ||||||
30 |
Did the test light flash when the engine was cranking? | -- | ||||||
31 |
Was a repair necessary? | -- | ||||||
32 | Replace the ICM. Refer to Ignition Control Module Replacement . Is the action complete? | -- | -- | |||||
33 | Inspect the PCM electrical connector and connections. Are the connections OK? | -- | ||||||
34 |
Was a repair necessary? | -- | ||||||
35 | Repair the connector or connections. Is the action complete? | -- | -- | |||||
Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Is the action complete? | -- | -- | ||||||
37 | Replace the spark plug wire. Refer to Spark Plug Wire Harness Replacement in Engine Electrical. Is the action complete? | -- | -- | |||||
38 | Replace the malfunctioinng ignition coil. Refer to Ignition Control Module Replacement . Is the action complete? | -- | -- | |||||
Does the test light blink on all cylinders? | -- | |||||||
Install a fuel pressure gauge and note pressure after ignition is ON for 2 seconds. Is the fuel pressure between the specified values? | 284-325 kPa (41-47 psi) | |||||||
41 |
Was spark plug replacement necessary? | -- | Go to Diagnostic Aids | |||||
42 | Repair the open in the fuel pump and injector ignition feed circuit. Refer to Fuel Pump Electrical Circuit Diagnosis . Is the action complete? | -- | -- | |||||
43 |
Does the engine start and continue to run? | -- | ||||||
44 |
Are any DTCs displayed? | -- | Go to Applicable DTC Table | System OK |