| Engine non-start |
| Engine does not crank |
- Security system/Immobilizer engaged
- Engine in shut-down mode
- ECM relay
- Battery
- Park/Neutral switch
- Starting system
- Engine seized
|
- Check that the security system is disarmed
- Read DTCs and refer to DTC Index for ECM relay tests
- Ensure the battery is in fully charged and serviceable condition
- For Park/Neutral switch tests. Refer to External Controls
article.
- For starting system tests. Refer to Starting System
article.
- For engine system tests. Refer to Engine
article.
|
| Engine cranks, but does not fire |
- Engine breather system disconnected/restricted
- Ignition system
- Fuel system
- Electronic engine controls
|
- Ensure the engine breather system is free from restriction and is correctly installed
- For ignition system tests. Refer to Engine Ignition
article.
- For fuel system tests. Refer to Fuel Charging and Controls
article.
- Read DTCs and refer to DTC Index for electronic engine control tests
|
| Engine cranks and fires, but will not start |
- Evaporative emissions purge valve
- Fuel pump
- Spark plugs
- Ignition coil failure(s)
|
|
| Difficult to start |
| Difficult cold start |
- Check engine coolant level/anti-freeze content
- Battery
- Electronic engine controls
- Exhaust gas recirculation (EGR) valve stuck open
- Fuel pump
- Evaporative emissions purge valve
|
|
| Difficult hot start |
- Injector leak
- Electronic engine controls
- Evaporative emissions purge valve
- Fuel pump
- Ignition system
- EGR valve stuck open
|
|
| Difficult to start after hot soak (vehicle standing, engine off, after engine has reached operating temperature) |
- Injector leak
- Electronic engine controls
- Evaporative emissions purge valve
- Fuel pump
- Ignition system
- EGR valve stuck open
|
|
| Engine cranks too fast/slow |
- Compressions high/low
- Battery
- Starting system
|
- Carry out compression tests. Refer to Engine
article.
- Ensure battery is in a fully charged and serviceable condition
- For starting system tests. Refer to Starting System
article.
|
| Engine stalls |
| Engine stalls soon after start |
- Breather system disconnected/restricted
- ECM relay
- Electronic engine controls
- Ignition system
- Air intake system restricted
- Air leakage
- Fuel lines
|
- Ensure the engine breather system is free from restriction and is correctly installed
- Read DTCs and refer to DTC Index for ECM relay tests
- Read DTCs and refer to DTC Index for electronic engine control tests
- For ignition system tests. Refer to Engine Ignition
article.
- Check for blockage in air cleaner element and air intake
- Check for leakage in air intake system
- For fuel system tests. Refer to Fuel Tank and Lines
article.
|
| Engine stalls on overrun |
- ECM relay
- Throttle position (TP) sensors
|
- Read DTCs and refer to DTC Index for ECM relay tests
- Read DTCs and refer to DTC Index for TP sensor tests
|
| Engine stalls at steady speed |
- ECM relay
- CKP sensor
- TP sensors
|
- Read DTCs and refer to DTC Index for ECM relay, CKP, and TP sensor tests
|
| Engine stalls with speed control enabled |
|
- Read DTCs and refer to DTC Index for ECM relay tests
|
| Engine stalls when maneuvering |
- ECM relay
- TP sensors
- Additional engine loads (PAS, air conditioning, etc.)
- Transmission malfunction
- CAN malfunction
|
- Read DTCs and refer to DTC Index for ECM relay, and TP sensor tests
- Check for excessive loads being placed on the engine from PAS, air conditioning systems etc.
- For transmission system tests. Refer to Diagnostic Strategy
article.
- For CAN network tests. Refer to Communications Network
article.
|
| Poor driveability |
| Engine hesitates/poor acceleration |
- Fuel pressure, fuel pump, fuel lines
- Injector leak
- Air leakage
- Electronic engine controls
- Ignition system
- EGR valve stuck
- Transmission malfunction
- Restricted pedal travel (carpet, etc.)
|
|
| Engine backfires |
- Fuel pump, fuel lines
- Air leakage
- Electronic engine controls
- Ignition system
- Sticking variable camshaft timing (VCT) hub
|
- For fuel system tests. Refer to Fuel Tank and Lines
article.
- Check for leakage from air intake system
- Read DTCs and refer to DTC Index for electronic engine control tests
- For ignition system tests. Refer to Engine Ignition
article.
- Read DTCs and refer to DTC Index for VCT system tests
|
| Engine surges |
- Fuel pump, fuel lines
- Electronic engine controls
- Ignition system
|
|
| Engine detonates/knocks |
- Electronic engine controls
- Fuel pump, fuel lines, fuel quality
- Air leakage
- Sticking VCT hub
|
- Read DTCs and refer to DTC Index for electronic engine control tests
- For fuel system tests. Refer to Fuel Tank and Lines
article.
- Check for leakage from air intake system
- Read DTCs and refer to DTC Index for VCT system tests
|
| No throttle response |
- Electronic engine controls
|
- Read DTCs and refer to DTC Index for electronic engine control tests
|
| Speed control inhibited or disabled |
- Default mode enabled
- Speed control, brake switch
- Electronic engine controls
- CAN fault
|
- Check message center for default message, read DTCs and refer to DTC Index .
- For speed control, and brake switch tests. Refer to Speed Control
article.
- Read DTCs and refer to DTC Index for electronic engine control tests
- For CAN network tests. Refer to Communications Network
article.
|
| Poor throttle response |
- Breather system disconnected/restricted
- Electronic engine controls
- Transmission malfunction
- Traction control event
- Air leakage
|
- Ensure engine breather system is free from restriction and is correctly installed
- Read DTCs and refer to DTC Index for electronic engine control tests
- For transmission system tests. Refer to Diagnostic Strategy
article.
- Check for leakage in air intake system
|
| Engine defaults, warning light and messages. Refer to the owner handbook |
- Park/Neutral switch
- Electronic engine controls
|
- For Park/Neutral switch tests. Refer to External Controls
article.
- Read DTCs and refer to DTC Index for electronic engine control tests
|