Chart 1
- Engine Runs Rough
- Engine Misses
- Stalls/Quits: Idle, Acceleration, Cruise
- Buck/Jerk
- Hesitation/Stumble
- Surge
- Unique Idle Concerns: Rolling Idle
Note. The engine may stall if left running while refueling, or it may restart if the key is not cycled to ACC or OFF position before refueling. Advise the customer to turn the engine off while refueling to avoid contamination or damage to the evaporative emission (EVAP) system.
| SYSTEM/COMPONENT | REFERENCE |
|---|---|
| Check the following parameter identification (PID)s: LONGFT1 (value between -20 and +20) VPWR (value between 10.5 and 17.0 volts, and within 0.5 volt of battery voltage) | LONGFT1 value low (-): Continue diagnosis. Concentrate checks in areas that cause the engine to run rich. LONGFT1 value high (+): Continue diagnosis. Concentrate checks in areas that cause the engine to run lean. VPWR not between 10.5 and 17.0 volts: VPWR between 10.5 and 17.0 volts, but not within 0.5 volt of battery voltage: CHECK B(+) supply to the powertrain control module (PCM) power relay. CHECK the VPWR circuit between the PCM and the PCM power relay. CHECK the PWR GND circuits. |
| Mass Air Flow (MAF) Sensor | GO to PINPOINT TEST DC . |
| Secondary Ignition System | GO to PINPOINT TEST JB . |
| Fuel Delivery System | GO to PINPOINT TEST HC . |
| Exhaust System | GO to PINPOINT TEST HF . |
| Positive Crankcase Ventilation (PCV) System | GO to PINPOINT TEST HG . |
| Evaporative Emissions (EVAP) System | CHECK for EVAP system blockages (engine stalls) or leaks (other symptoms). REFER to EVAPORATIVE EMISSIONS . |
| Heated Oxygen Sensor (HO2S) | GO to PINPOINT TEST DZ . |
| Base Engine | REFER to ENGINE . |
| Intake Air System | GO to PINPOINT TEST HU . |
| Additional Testing | GO to PINPOINT TEST Z . |
| Additional Checks: Correct PCM vehicle identification (VID) block information. Refer to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) . Be aware of the engine RPM/speed limiting functions of the PCM (look for incorrect high vehicle speed signal from ABS). Driveline and electronically controlled continuously variable transaxle (CVT) A/C system (for surge with A/C on) Speed control system (for surge with speed control on) |
SYMPTOM CHART
Chart 2
Engine/Vehicle Starting Concerns: No Start/Vehicle Disabled
| SYSTEM/COMPONENT | REFERENCE |
|---|---|
| Ignition switch inputs to the PCM, power and ground to the modules, the traction battery contractor status, and the vehicle mode. | GO to PINPOINT TEST AA . |
ENGINE/VEHICLE STARTING CONCERNS: NO START/VEHICLE DISABLED - SYMPTOM CHART
Chart 3
Engine/Vehicle Starting Concerns: No Start/Normal Crank
| SYSTEM/COMPONENT | REFERENCE |
|---|---|
| Add-on Anti-Theft Devices | Visual. CHECK with the customer. |
| Fuel/Ignition | GO to PINPOINT TEST A . |
| Exhaust System (restrictions) | GO to PINPOINT TEST HF . |
| Base Engine | REFER to ENGINE . |
| Additional Testing | GO to PINPOINT TEST Z . |
ENGINE/VEHICLE STARTING CONCERNS: NO START/NORMAL CRANK - SYMPTOM CHART
Chart 4
Engine Backfires
| SYSTEM/COMPONENT | REFERENCE |
|---|---|
| Secondary Ignition | GO to PINPOINT TEST JB . |
| Fuel Delivery System | GO to PINPOINT TEST HC . |
| Base Engine | REFER to ENGINE . |
| Exhaust System | GO to PINPOINT TEST HF . |
| Additional Testing | GO to PINPOINT TEST Z . |
ENGINE BACKFIRES - SYMPTOM CHART
Chart 5
Lack/Loss of Power
Note. Verify the symptom is reported under normal driving conditions without excessive engine/vehicle load. Also, be aware of the engine RPM/speed limiting functions of the PCM.
| SYSTEM/COMPONENT | REFERENCE |
|---|---|
| Air Cleaner Element | Visual |
| Check the following PIDs: LONGFT1 (value between -20 and +20) | LONGFT1 value low (-): Continue diagnosis. Concentrate checks in areas that cause the engine to run rich. LONGFT1 value high (+): Continue diagnosis. Concentrate checks in areas that cause the engine to run lean. |
| Fuel Delivery System | GO to PINPOINT TEST HC . |
| Secondary Ignition System | GO to PINPOINT TEST JB . |
| Mass Air Flow (MAF) Sensor | GO to PINPOINT TEST DC . |
| Exhaust System | GO to PINPOINT TEST HF . |
| Variable Camshaft Timing (VCT) System | GO to PINPOINT TEST HK . |
| Base Engine | REFER to ENGINE . |
| Transaxle | REFER to AUTOMATIC TRANSAXLE/TRANSMISSION EXTERNAL CONTROLS . |
| Motor Electronics Cooling System | REFER to TRANSAXLE/TRANSMISSION COOLING . |
| Brake System (brake drag or binding) | REFER to FRONT DISC BRAKE . |
| Additional Testing | GO to PINPOINT TEST Z . |
| Additional Checks: Customer driving habits Correct PCM vehicle identification (VID) block information. Refer to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) . Engine RPM/speed limiting functions of the PCM (look for an incorrect high vehicle speed signal from the ABS module). | Visual. REFER to the applicable part in the Workshop article. |
LACK/LOSS OF POWER - SYMPTOM CHART
Chart 6
Engine Spark Knock
| SYSTEM/COMPONENT | REFERENCE |
|---|---|
| Verify the engine operates at the normal temperature. | Visual. REFER to ENGINE COOLING , to diagnose any cooling system concerns that are present. |
| Verify correct coolant level and coolant concentration. | REFER to ENGINE COOLING , for correct fill concentrations and fill procedures. |
| Mass Air Flow (MAF) Sensor | GO to PINPOINT TEST DC . |
| Base Engine | REFER to ENGINE . |
| Fuel Delivery System | GO to PINPOINT TEST HC . |
| Secondary Ignition System | GO to PINPOINT TEST JB . |
| PCV System | GO to PINPOINT TEST HG . |
| Engine Oil Quality | Visual |
| Knock Sensor | GO to PINPOINT TEST DG . |
| Additional Testing | GO to PINPOINT TEST Z . |
ENGINE SPARK KNOCK - SYMPTOM CHART
Chart 7
Poor Fuel Economy
Note. Since driving styles can have a significant influence on fuel economy, verify the concern before starting an in-depth diagnosis.
Note. Excessive temperature in the high voltage traction battery will cause the engine to run longer than normal to cool the high voltage traction battery and will result in reduced fuel economy. The high voltage traction battery cooling system should be checked for proper operation if there is no obvious cause for the additional cooling request. The following external factors may also contribute to poor fuel economy conditions
- stop/go driving
- incorrect tire pressure/size
- vehicle loads (such as trailer towing)
- extended winter warm-up conditions
- high speed driving
- regenerative braking disabled
- high voltage traction battery temperatures
- incorrect axle ratio
- road/weather conditions
- aftermarket add-ons
- short run operations
- customer expectations
| SYSTEM/COMPONENT | REFERENCE |
|---|---|
| Transaxle Fluid Level | Visual. REFER to the Workshop article |
| Check the following PIDs: LONGFT1 (value between -20 and +20) VPWR (value between 10.5 and 17.0 volts, and within 0.5 volt of battery voltage) | LONGFT1 value low (-): Continue diagnosis. Concentrate checks in areas that cause the engine to run rich. LONGFT1 value high (+): Continue diagnosis. Concentrate checks in areas that cause the engine to run lean. VPWR not between 10.5 and 17.0 volts: VPWR between 10.5 and 17.0 volts, but not within 0.5 of battery voltage: CHECK the B+ supply to the power relay. CHECK the VPWR circuit between the PCM and the power relay. CHECK the PWR GND circuits. |
| Verify the engine operates at normal temperature. | Visual. REFER to ENGINE COOLING , to diagnose any cooling system concerns that are present. |
| Secondary Ignition System | GO to PINPOINT TEST JB . |
| Fuel System | GO to PINPOINT TEST HC . |
| Exhaust System | GO to PINPOINT TEST HF . |
| Variable Camshaft Timing (VCT) System | GO to PINPOINT TEST HK . |
| Automatic Transaxle | REFER to AUTOMATIC TRANSAXLE/TRANSMISSION EXTERNAL CONTROLS . |
| PCV System | GO to PINPOINT TEST HG . |
| Additional Checks: Correct PCM vehicle identification (VID) block information. Refer to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) . Brake drag Base engine concerns Incorrect PCV valve Contaminated MAF sensor Intake air system | REFER to the applicable part in the Workshop article. |
| Additional Testing | GO to PINPOINT TEST Z . |
POOR FUEL ECONOMY - SYMPTOM CHART
Chart 8
Emissions Compliance
| SYSTEM/COMPONENT | REFERENCE |
|---|---|
| Emissions Related Systems | GO to PINPOINT TEST EM . |
EMISSIONS COMPLIANCE - SYMPTOM CHART
Chart 9
Warning Indicators: Malfunction Indicator Lamp (MIL), Hazard Indicator Lamp, Powertrain Malfunction Indicator (Wrench) Lamp, Temperature Warning Indicator Lamp, Check Fuel Cap Indicator Lamp
Note. If the symptom is both MIL ON and exhaust emission test failure, GO directly to Chart 8. If the vehicle is disabled, GO directly to Chart 2. If the engine is a no start, GO directly to Chart 3.
- If the engine runs rough at idle, GO directly to Chart 1.
| SYSTEM/COMPONENT | REFERENCE |
|---|---|
| Verify the fuel filler cap is correctly tightened. | Visual |
| Instrument Cluster | REFER to INSTRUMENT CLUSTER AND PANEL ILLUMINATION . |
| Additional Testing | GO to PINPOINT TEST Z . |
SYSTEM REFERENCE CHART
Chart 10
Oil System Concerns: High Oil Consumption, Leaks
| SYSTEM/COMPONENT | REFERENCE |
|---|---|
| PCV System | GO to PINPOINT TEST HG . |
| Base Engine | REFER to ENGINE . |
| Additional Checks External leaks Correct dipstick Correct oil viscosity | Visual |
OIL SYSTEM CONCERNS: HIGH OIL CONSUMPTION, LEAKS - SYMPTOM CHART
Chart 11
Cooling System Concerns: Electric Engine Cooling Fan(s) Does Not Operate (Low, Medium or High Speed)
| SYSTEM/COMPONENT | REFERENCE |
|---|---|
| Electric Cooling Fan Components | GO to PINPOINT TEST KF . |
| Cooling System | REFER to ENGINE COOLING . |
| Motor Electronics Cooling System | REFER to TRANSAXLE/TRANSMISSION COOLING . |
COOLING SYSTEM CONCERNS: ELECTRIC ENGINE COOLING FAN(S) DOES NOT OPERATE (LOW, MEDIUM OR HIGH SPEED) - SYMPTOM CHART
Chart 12
Cooling System Concerns: Electric Engine Cooling Fan(s) Always Runs
Note. This chart is intended to only diagnose an electric engine cooling fan that always runs with a cool engine and the A/C and defroster off.
| SYSTEM/COMPONENT | REFERENCE |
|---|---|
| Electric Cooling Fan Components/ACPSW | GO to PINPOINT TEST KF . |
| Cooling System | REFER to ENGINE COOLING . |
| Motor Electronics Cooling System | REFER to TRANSAXLE/TRANSMISSION COOLING . |
COOLING SYSTEM CONCERNS: ELECTRIC ENGINE COOLING FAN(S) ALWAYS RUNS - SYMPTOM CHART
Chart 13
Exhaust System Concerns: Visible Smoke
Note. Black smoke indicates a rich fuel mixture, blue smoke indicates burning oil, and white smoke indicates water in the combustion chamber.
| SYSTEM/COMPONENT | REFERENCE |
|---|---|
| Base Engine | REFER to ENGINE . |
| Fuel Delivery System Black Smoke | GO to PINPOINT TEST HC . |
| Ignition System Black Smoke | GO to PINPOINT TEST JB . |
| PCV System Blue Smoke | GO to PINPOINT TEST HG . |
EXHAUST SYSTEM CONCERNS: VISIBLE SMOKE - SYMPTOM CHART
Chart 14
Fuel System Concerns: Fuel Odor, Engine Compartment
| SYSTEM/COMPONENT | REFERENCE |
|---|---|
| EVAP System | CHECK for EVAP system leaks. REFER to EVAPORATIVE EMISSIONS . |
| Fuel System | Visual. REFER to FUEL TANK & LINES . |
FUEL SYSTEM CONCERNS: FUEL ODOR, ENGINE COMPARTMENT - SYMPTOM CHART
Chart 15
Engine Noise (Under Hood)
Note. Attempt to identify the source of the noise. If the noise is from a source other than those listed below, refer to NO DIAGNOSTIC TROUBLE CODES (DTCS) PRESENT SYMPTOM CHART INDEX (for noise such as spark knock) or the applicable Workshop article part.
| SYSTEM/COMPONENT | REFERENCE |
|---|---|
| Secondary Ignition System Snap noise that may be due to secondary ignition arcing. | CHECK the condition of the coil-on-plug (COP) spark plug boots. |
ENGINE NOISE (UNDER HOOD) - SYMPTOM CHART
Chart 16
Climate Control: Lack of A/C Cooling, A/C Not Functioning, A/C Always On, A/C Compressor Runs Continuously
| SYSTEM/COMPONENT | REFERENCE |
|---|---|
| A/C System | If sent here from a Workshop article with a WACF PID indicating a fault (or YES), GO to DTC CHART and follow the direction for KOEO DTC P0645. For all others, REFER to CLIMATE CONTROL SYSTEM - GENERAL INFORMATION AND DIAGNOSTICS . |
A/C SYSTEM - SYMPTOM CHART
Chart 17
Exhaust System Concerns: Odor (Sulfur or Rotten Egg Smell)
Note. A slight sulfur smell may be normal. Catalysts with less than 8,000-16,000 kilometers (5,000-10,000 miles) (new vehicle or catalyst) are likely to have a sulfur smell due to the highly active state of new catalysts. Installing a new catalyst may actually make the symptom worse.
| SYSTEM/COMPONENT | REFERENCE |
|---|---|
| Check for any driveability or exhaust smoke symptoms | GO to NO DIAGNOSTIC TROUBLE CODES (DTCS) PRESENT SYMPTOM CHART INDEX for direction to repair other symptoms. |
| Fuel Delivery System | GO to PINPOINT TEST HC . |
| EVAP System | CHECK for EVAP system leaks. REFER to EVAPORATIVE EMISSIONS . |
| Fuel Source | Talk with the customer. Since sulfur content can vary in different fuels, suggest trying a different fuel source. |
EXHAUST SYSTEM CONCERNS: ODOR (SULFUR OR ROTTEN EGG SMELL) - SYMPTOM CHART