Engine Cranks But Does Not Start

ENGINE CRANKS BUT DOES NOT START

Engine Cranks But Does Not Start:

POSSIBLE CAUSES
- No start pre-test
- Powertrain fuses open
- Secondary indicators present
- Engine mechanical problem
- (F142) ASD relay output circuit open
- Fuel contamination

DIAGNOSTIC TEST

1. NO START PRE-TEST

NOTE: The following list of items must be checked before continuing with any no start tests.

The battery must be fully charged and in good condition. A low charged battery may produce invalid test results. If the battery is low, charge the battery and then attempt to start the vehicle by cranking the engine for 15 seconds, 3 consecutive times.
This will allow any DTCs to set that may have been erased due to a dead battery.
Try to communicate with PCM if not able to communicate check fuses.
Make sure the Powers and Ground to the PCM are OK.
Make sure the PCM communicates with the scan tool and that there are no DTCs stored in the PCM memory. If the PCM reports a No Response condition, refer to Body Control Systems for the proper tests.
Read the PCM DTCs with the scan tool. If any DTCs are present, they must be repaired before continuing with any other No Start diagnostic tests. Refer to Diagnostic Trouble Code Charts.
Make sure that the Bus is functional. Attempt to communicate with the Instrument Cluster and VTSS, If you are unable to establish communications refer to Body Control Systems for the proper Diagnostic procedures.
The Sentry Key Immobilizer System must be operating properly. Check for proper communication with the scan tool and check for DTCs that may be stored in the Sentry Key Immobilizer Module (SKREEM). Repair the DTC(s) before continuing.
If no DTCs are found, using the scan tool, select Clear PCM (BATT Disconnect).
Crank the engine several times. Using the scan tool, read DTCs. If a DTC is present perform the DTC diagnostics before continuing.

Q: Were any problems found?

YES: Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 2

2. OPEN FUSE
Check for any open fuses in the IPM or Junction Block that may be related to the No Start condition.

Q: Are any of the fuses open?

YES: Replace the open fuse and check the related circuit(s) for a short to ground.
Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 3

3. SECONDARY INDICATORS PRESENT
Ignition on, engine not running.
With the scan tool, under DTCs & Related Functions, read the Secondary Indicators while cranking the engine.

Q: Are there any Secondary Indicators present while cranking the engine?

YES: Refer to the Engine Electrical Diagnostics group and perform the tests related to the secondary indicator that is reported by the scan tool.
Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 4

4. POSSIBLE MECHANICAL PROBLEMS
Check for any of the following conditions/mechanical problems.
ENGINE VALVE TIMING - must be within specifications, check for broken timing components
ENGINE COMPRESSION - must be within specifications
ENGINE EXHAUST SYSTEM - must be free of any restrictions or leaks.

Q: Are there any engine mechanical problems?

YES: Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 5

5. (F142) ASD RELAY OUTPUT CIRCUIT OPEN




Turn the ignition off.
Remove the ASD relay from the PDC.
Disconnect the C3 PCM harness connector.
Verify the ASD Relay is getting voltage on the Fused B+ circuits before continuing.

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 ASD Relay Output circuit from the ASD Relay connector to the appropriate terminals of special tool #8815, Ignition coil, and the fuel injectors.

Q: Is the resistance below 5.0 ohms?

YES: Go To 6
NO: Repair the open in the (F142) ) ASD Relay Output circuit.
Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

6. FUEL PUMP DELIVERY
Verify that the Fuel tank is not empty before continuing.
Follow the diagnostics for Checking Fuel Delivery in Engine Electrical Diagnostic.

Q: Was the No Start condition solved after following the above diagnostic test?

YES: Test Complete.
NO: Check for contamination/water in the fuel. Make sure the fuel being used in this vehicle meets manufactures Fuel Requirement.
Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test