Refer to
Cell 20: CKP, CMP, KS and Traction Control System
for complete circuit details.
Description
The Engine Cranks but Does Not Run diagnostic table assumes that battery condition and engine cranking speed are OK. If the battery condition and the cranking speed are not OK, refer to Starting System Check or Charging System Check in Engine Electrical for diagnosis. Make sure that there is adequate fuel in the tank(s).
Diagnostic Aids
Important:
• Remove any debris from the PCM\TAC module connector surfaces before
servicing the PCM\TAC module. Inspect the PCM\TAC module connector gaskets
when diagnosing/replacing the modules. Ensure that the gaskets are installed
correctly. The gaskets prevent contaminate intrusion into the PCM\TAC
modules. • For any test that requires probing the PCM or a component
harness connector, use the Connector Test Adapter Kit J 35616
. Using this kit prevents damage
to the harness/component terminals. Refer to
Using Connector Test Adapters
in Wiring Systems.
| • | Inspect the duct work between the Mass Air Flow (MAF) sensor and the throttle body for air leaks. |
| • | A malfunctioning MAF sensor may cause a no start or a stall after start. If you suspect this, disconnect the MAF sensor. The PCM will default to the speed density (MAP, IAT, RPM) in order to calculate the load and the air flow. If this corrects the condition and the connections are OK, replace the MAF sensor. |
| • | For an intermittent condition, refer to Symptoms . |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step verifies the IGN relay for proper operation. The IGN relay supplies voltage to the injectors and the ignition coils. When the IGN relay is not operating properly, a no start condition occurs. If the test lamp does not illuminate, this indicates the IGN relay is not suppling a voltage to the fuses.
-
This step is testing for a DTC that sets while the engine is cranking.
-
This step is testing for a grounded ignition feed circuit for the crankshaft position sensor and the camshaft position sensor. When the ignition feed circuit is shorted, a no start occurs and no DTCs are set. The ignition feed circuits are connected internally within the PCM. The PCM cannot detect that the engine is cranking with a grounded ignition feed circuit. If no engine speed is displayed on the scan tool, inspect the ignition feed circuit for a short to ground.
The scan tool may reset if the battery is at a low state of charge. The battery may need to be charged to perform this step.
-
This step is testing for B+ supply to the crankshaft position sensor.
-
The ignition feed circuits for the Camshaft and Crankshaft Position sensors is internally connected within the PCM. A short to ground on either circuit will cause a no start condition.
-
The fuel cap may need to be removed in order to hear if the fuel pump is operating.
Step | Action | Value(s) | Yes | No | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||||||||||||
Does the test lamp illuminate on both sides of all the fuses? | -- | Go to Ignition Relay Diagnosis for further diagnosis | ||||||||||||
3 | Monitor the Diagnostic Trouble Code (DTC) option using the scan tool. Does the scan tool display any Throttle Actuator Control (TAC) system DTCs? | -- | Go to the applicable DTC table | |||||||||||
4 |
Important: Monitor the BCM for DTCs related to Vehicle Theft Deterrent (VTD) system. This indicates a concern with the Column Lock or VTD fuel enable system. If a BCM DTC is stored, refer to Diagnostic System Check - Body Control System in Body Control Systems. Select the Diagnostic Trouble Code (DTC) option, then the DTC Information option using the scan tool. Is P0230, P0335, P0336, P0601, P0602, P0604, or P0606 displayed? | -- | Go to the applicable DTC table | |||||||||||
Did a DTC set while cranking the engine? | -- | Go to the applicable DTC table | ||||||||||||
Monitor the engine speed while cranking the engine. Is engine RPM indicated on the scan tool? | -- | |||||||||||||
Does the DMM display near the specified value? | B+ | |||||||||||||
Does the DMM display near the specified value? | B+ | |||||||||||||
9 | Test the Camshaft and Crankshaft Position sensor ignition feed circuits for a short to ground. Refer to Testing for Short to Ground in Wiring Systems. Did you find and correct the condition? | -- | ||||||||||||
10 | Monitor the engine coolant temperature using the scan tool. Is the engine coolant temperature on the scan tool close to the actual engine temperature? | -- | Go to DTC P0118 Engine Coolant Temperature (ECT) Sensor Circuit High Voltage | |||||||||||
Enable the fuel pump using the scan tool. Does the fuel pump operate? | -- | |||||||||||||
12 |
Is the fuel pressure within the specified range? | 380-420 kPa (55-61 psi) | Go to Fuel System Diagnosis | |||||||||||
13 | Perform the following additional inspections:
Did you find and correct the condition? | -- | Go to Symptoms for diagnosis | |||||||||||
14 | Replace the CKP sensor. Refer to Crankshaft Position Sensor Replacement . Is the action complete? | -- | -- | |||||||||||
15 | Replace the CMP sensor. Refer to Camshaft Position Sensor Replacement . Is the action complete? | -- | -- | |||||||||||
16 |
Important: Program the replacement PCM. Refer to Powertrain Control Module/Throttle Actuator Control Module Replacement . Replace the PCM. Is the action complete? | -- | -- | |||||||||||
17 |
Does the engine start and continue to run? | -- | ||||||||||||
18 |
Are any DTCs displayed? | -- | Go to the applicable DTC table | |||||||||||
19 | Select the Capture Info option and the Review Info option using the scan tool. Are any DTCs displayed that you have not diagnosed? | -- | Go to the applicable DTC table | System OK |
