INSPECTION AND VERIFICATION
| CAUTION | Diagnosis by substitution from a donor vehicle is NOT acceptable. Substitution of control modules does not guarantee confirmation of a fault, and may also cause additional faults in the vehicle being tested and/or the donor vehicle. |
- Verify the customer concern.
- Visually inspect for obvious signs of mechanical or electrical damage. VISUAL INSPECTION Mechanical Electrical Engine oil level Cooling system coolant level Fuel level Fuel contamination/grade/quality Fuses Wiring harness Loose or corroded electrical connectors Ignition coils Sensor(s) Engine Control Module (ECM)
- If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step
- If the cause is not visually evident, verify the symptom and refer to the Symptom Chart, alternatively, check for Diagnostic Trouble Codes (DTCs) and refer to the DTC Index.
SYMPTOM CHART
| Symptom | Possible Cause | Action |
|---|---|---|
| Engine cranks, but does not fire | Engine breather system disconnected/restricted Engine ignition system Fuel system Electronic engine controls | Ensure the engine breather system is free from restriction and is correctly installed Read DTCs and refer to DTC Index provided here for engine ignition system tests For fuel system tests. Refer to FUEL TANK AND LINES . Read DTCs and refer to the DTC Index for electronic engine controls. Refer to ELECTRONIC ENGINE CONTROLS . |
| Engine cranks and fires, but will not start | Evaporative emissions purge valve Fuel pump Spark plugs HT short to ground (tracking) check rubber boots for cracks/damage Ignition coil failure(s) | For purge valve tests. Refer to EVAPORATIVE EMISSIONS . For fuel system tests. Refer to FUEL TANK AND LINES . For spark plug tests, Visually inspect the spark plug for cracks, damage, carbon buildup or wet fouling, check the condition of the ground electrode, the center electrode tip and the spark plug HT contact and confirm that the spark plug gap is correctly set using a wire gauge taking care not to cause damage to the center or ground electrode tips. Install new spark plug(s) as required. For engine ignition coil circuit tests, check for DTCs and refer to the DTC Index |
| Difficult cold start | Engine coolant level-anti-freeze content Battery Electronic engine controls Fuel pump Purge valve | Check the engine coolant level and anti-freeze content. Refer to SPECIFICATIONS . Ensure the battery is in a fully charged and serviceable condition Read DTCs and refer to DTC Index for electronic engine controls. Refer to ELECTRONIC ENGINE CONTROLS . For fuel system tests. Refer to FUEL TANK AND LINES . For purge valve tests. Refer to EVAPORATIVE EMISSIONS . |
| Difficult hot start | Injector leak Electronic engine controls Purge valve Fuel pump Engine ignition system | Check for leaking injectors Read DTCs and refer to the DTC Index for electronic engine controls. Refer to ELECTRONIC ENGINE CONTROLS . For purge valve tests. Refer to EVAPORATIVE EMISSIONS . For fuel system tests. Refer to FUEL TANK AND LINES . Read DTCs and refer to DTC Index provided here for engine ignition system tests |
| Difficult to start after hot soak (vehicle standing, engine off, after engine has reached operating temperature) | Injector leak Electronic engine controls Purge valve Fuel pump Engine ignition system | Check for leaking injectors Read DTCs and refer to DTC Index for electronic engine control tests. Refer to ELECTRONIC ENGINE CONTROLS . For purge valve tests. Refer to EVAPORATIVE EMISSIONS . For fuel system tests. Refer to EVAPORATIVE EMISSIONS . Read DTCs and refer to DTC Index provided here for engine ignition system tests |
| Engine stalls soon after start | Breather system disconnected/restricted Electronic engine control Engine 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 electronic engine control. Refer to ELECTRONIC ENGINE CONTROLS . Read DTCs and refer to DTC Index provided here for engine ignition system tests Check for blockage in air filter element and air intake system For fuel system tests. Refer to FUEL TANK AND LINES . |
| Engine hesitates/poor acceleration | Fuel pressure, pump and lines Injector leak Air leakage Electronic engine controls Engine ignition system Transmission malfunction Restricted pedal travel (carpet, etc) | For fuel system tests. Refer to FUEL TANK AND LINES . Check for injector leak Check for leakage from air intake system Read DTCs and refer to DTC Index for electronic engine control tests. Refer to ELECTRONIC ENGINE CONTROLS . Read DTCs and refer to DTC Index provided here for engine ignition system tests For transmission tests. Refer to DIAGNOSTICS . Ensure accelerator pedal is free from restriction |
| Engine backfires | Fuel pump and lines Air leakage Electronic engine controls Engine ignition system Sticking Variable Camshaft Timing (VCT) hub | For fuel system tests. Refer to FUEL TANK AND LINES . Check for leakage in air intake system Read DTCs and refer to DTC Index for electronic engine controls. Refer to ELECTRONIC ENGINE CONTROLS . Read DTCs and refer to DTC Index provided here for engine ignition system tests Read DTCs and refer to DTC Index for VCT tests. Refer to ELECTRONIC ENGINE CONTROLS . |
| Engine surges | Fuel pump and lines Electronic engine controls Engine ignition system | For fuel system tests. Refer to FUEL TANK AND LINES . Read DTCs and refer to DTC Index for electronic engine controls. Refer to ELECTRONIC ENGINE CONTROLS . Read DTCs and refer to DTC Index provided here for engine ignition system tests |
| Engine detonates/knocks | Electronic engine controls Fuel pump and lines Air leakage Sticking VCT hub | Read DTCs and refer to DTC Index for electronic engine controls For fuel system tests. Refer to FUEL TANK AND LINES . Check for leakage from air intake system Read DTCs and refer to DTC Index for VCT tests. Refer to ELECTRONIC ENGINE CONTROLS . |
| No throttle response | Electronic engine controls | Read DTCs and refer to DTC Index for electronic engine control tests |
| Poor throttle response | Breather system disconnected/restricted Electronic engine control Transmission malfunction Traction control event Air leakage | Ensure the engine breather system is free from restriction and is correctly installed Read DTCs and refer to DTC Index for electronic engine control tests. Refer to ELECTRONIC ENGINE CONTROLS . For transmission tests. Refer to DIAGNOSTICS . Check for leakage from air intake system |
DTC INDEX
Note. If the control module or a component is suspect and the vehicle remains under manufacturer warranty, refer to the Warranty Policy and Procedures information or determine if any prior approval program is in operation, prior to the installation of a new module/component.
Note. Generic scan tools may not read the codes listed, or may read only five digit codes. Match the five digits from the scan tool to the first five digits of the seven digit code listed to identify the fault (the last two digits give extra information read by the manufacturer-approved diagnostic system).
Note. When performing electrical voltage or resistance tests, always use a digital multimeter (DMM) accurate to three decimal places, and with an up-to-date calibration certificate. When testing resistance, always take the resistance of the DMM leads into account.
Note. Check and rectify basic faults before beginning diagnostic routines involving pinpoint tests.
Note. If DTCs are recorded and, after the pinpoint tests have been carried out, the fault is not present, an intermittent concern may be the cause. Always check for loose connections and corroded terminals.
| DTC | Description | Possible Cause | Action |
|---|---|---|---|
| P131500 | Persistent misfire | ECM to ignition coil circuit fault Cylinder misfire DTCs also set Ignition coil failure Spark plug failure/fouled/incorrect gap Fuel delivery pressure low Fuel injector circuit faults Injector DTCs also set | Check for DTCs indicating an ignition or fuel related fault. Rectify as necessary. |
| P136700 | Ignition spare | Ignition failure signal circuit: short circuit to ground Ignition failure signal circuit: open circuit Ignition failure signal circuit: short circuit to power Ignition coil failure | Check the ignition failure signal circuit. Refer to the electrical information. Rectify as necessary. Install a new coil as necessary. See IGNITION COIL-ON-PLUG . |
| P136800 | Ignition spare | Ignition failure signal circuit: short circuit to ground Ignition failure signal circuit: open circuit Ignition failure signal circuit: short circuit to power Ignition coil failure | Check the ignition failure signal circuit. Refer to the electrical information. Rectify as necessary. Install a new coil as necessary. See IGNITION COIL-ON-PLUG . |
Scheme 2
Scheme 3
- Disconnect the battery ground cable. Refer to «SPECIFICATIONS»(ref-531959-S27829531522013022000000) .
- Remove the engine cover. Refer to «ENGINE COVER»(ref-531951-S06303498242013022000000) .
- Disconnect the 6 ignition coil-on-plugs.