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Engine Controls - Self-Diagnostics: Other Suzuki Vitara I

Testing & Diagnostics 3 illustrations ~4583 words

FAIL-SAFE FUNCTION

When a malfunction has occurred in specific areas of engine and emission control system, ECM enters "fail-safe function". When vehicle is operating in fail-safe function, ECM allows a lower level of engine performance to be available, allowing vehicle to be driven for service. When malfunction occurs a failure signal is sent to ECM, and ECM control over affected sensors and actuators is maintained on the basis of standard signals and/or a back-up program stored in ECM. While in fail-safe mode ECM ignores failure signal and/or CPU inputs. ECM will remain in fail-safe mode as long as malfunction is detected, fail-safe mode is canceled when ECM detects normal conditions. For fail-safe function parameters, and detected item. (Scheme 50)

Scheme 50

Scheme 50: FAIL-SAFE FUNCTION
Scheme 50: FAIL-SAFE FUNCTION

FREEZE FRAME DATA

Engine operating conditions are required to be captured and stored in ECM memory whenever a malfunction is detected. Data captured in this manner is called FREEZE FRAME data. Freeze frame data is similar to a single record of operating conditions. Whenever a malfunction is detected, corresponding record of operating conditions is recorded in the freeze frame buffer. ECM can store freeze frame data for 3 different malfunctions.

Freeze frame data can only be overwritten with data associated with a misfire or fuel trim malfunction. Misfire data takes priority over all other data because of its possible part-damaging (oxygen sensors, catalytic converters, etc.) effects. Freeze frame data will not be erased unless associated DTC is cleared from ECM memory.

Priority Of Freeze Frame Data

ECM has 4 frames where freeze frame data can be stored. The first frame stores freeze frame data of malfunction which was detected first. However, freeze frame data stored in this frame is updated according to priority described. If malfunction as described in the upper square No. 1 is detected while the freeze frame data in the lower square No. 2 has been stored, freeze frame data No. 2 will be updated by freeze frame data No. 1.

In 2nd through 4th frames, freeze frame data of each malfunction is stored in the order malfunctions are detected. This data is not updated. Examples of how freeze frame data are stored when two or more malfunctions are detected are shown in illustration. (Scheme 51)

Scheme 51

Scheme 51: Priority Of Freeze Frame Data
Scheme 51: Priority Of Freeze Frame Data

MALFUNCTION INDICATOR LIGHT

All models are equipped with a Malfunction Indicator Light (MIL), located at instrument cluster. (Scheme 52) As a bulb check, MIL illuminates for about 2 seconds when ignition switch is turned to ON position and engine is not running. MIL also illuminates when a system failure has been detected and a corresponding DTC has been set in ECM memory. MIL may also flash if ECM detects an engine misfire sever enough to cause catalytic converter failure. Not all trouble codes will activate MIL. If MIL is ON and no DTCs are in memory, problem may be intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.

Malfunction Indicator Light Check

  1. Turn ignition switch to ON position. If MIL illuminates, go to next step. If MIL does not illuminate, see «A-1: MALFUNCTION INDICATOR LIGHT INOPERATIVE»(ref-158406-S23589857442003092400000) under SYSTEM TESTS. If problem is found, repair as necessary and retest system for normal operation.
  2. Start engine. If MIL turns OFF, system is okay. If driveability problems are present, go to «TROUBLE SHOOTING - NO CODES»(ref-158314) article. If MIL remains illuminated, check for DTCs. See «RETRIEVING DIAGNOSTIC TROUBLE CODES»(ref-158406-S05859488132003092400000) . If no DTC is stored in ECM memory and MIL is illuminated, see «A-3: MALFUNCTION INDICATOR LIGHT REMAINS ILLUMINATED»(ref-158406-S15058958012003092400000) under SYSTEM TESTS. If problem is found, repair as necessary and retest system for normal operation.

Scheme 52

Scheme 52
Scheme 52

WARM-UP CYCLE

A warm-up cycle means sufficient vehicle operation such that coolant temperature has risen by at least 70°F (22°C) from engine starting point and reaches a minimum temperature of 160°F (70°C).

DRIVE CYCLE

A "Driving Cycle" consists of engine start-up and engine shutoff.

DRIVING CYCLE DETECTION LOGIC

Malfunction detected in first driving cycle is stored in ECM memory (in the form of pending DTC and freeze frame data) but MIL does not illuminate at this time. MIL illuminates at the second detection of same malfunction also in the next driving cycle.

SUMMARY

If no DTCs are present, and driveability symptoms exist, proceed to TROUBLE SHOOTING - NO CODES article for diagnosis by symptom (i.e., rough idle, no start, etc.).

SYSTEM TESTS

CAUTIONWhen battery or ECM is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until adaptation systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES - SUZUKI article in GENERAL INFORMATION before disconnecting battery.

Note. Before replacing any component that scan tool suggests are faulty. Ensure that all wiring connections and harness connectors are okay. Ensure that power and ground circuits are functioning properly. To identify ECM terminals referenced in testing, see PIN VOLTAGE CHARTS article. To identify circuits and wire colors referenced in testing, see ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.

SymptomPerform Test
Malfunction Indicator Light InoperativeA-1
Malfunction Indicator Light Remains IlluminatedA-2
A-3: Malfunction Indicator Light Inoperative & Engine Does Not Start (ECM Power & Ground Circuit Check)A-3
Engine System CheckA-4

SYMPTOM INDEX

Condition

When ignition switch is turned to ON position, main relay is energized and supplies Engine Control Module (ECM) with battery voltage. As ECM is supplied with ignition power, MIL turns ON. After engine starts, MIL will turn off if no malfunction is detected. If a malfunction is detected, MIL will remain on until system is repaired.

When ignition switch is turned to ON position, main relay is energized by the Engine Control Module (ECM) and supplies ECM with main power. As ECM is supplied with main power, it will turn ON the MIL. After engine starts, MIL will turn OFF if no malfunction is detected. If a malfunction is detected, MIL will remain ON until system is repaired.

When ignition switch is turned to ON position, main relay turns ON (contact point closes) and main power is supplied to Engine Control Module (ECM).

Engine System Check is the starting point for any driveability complaint diagnosis. Engine System Check is an organized approach to identifying problems created by an electronic engine control system malfunction. Before any DTC(s) are retrieved, perform a visual underhood inspection, checking battery and grounds for clean and tight connections. Check for poor connections or damage to wiring harness and connectors. Check for corroded terminals or corrosion buildup on any connection. If problem is found, repair as necessary. If no problem is found during initial inspection perform Engine System Check.

Code Definition

  1. DTC P0031: Heated Oxygen Sensor No. 1 - Heater Circuit - Low Input.
  2. DTC P0032: Heated Oxygen Sensor No. 1 - Heater Circuit - High Input.

DTC P0031 is set when Engine Control Module (ECM) detects Heated Oxygen Sensor No. 1 (HO2S-1) heater circuit voltage input is higher than 13.99 volts while HO2S-1 heater is ON. DTC P0032 is set when ECM detects HO2S-1 heater circuit voltage input is lower than 11.72 volts while HO2S-1 heater is ON. MIL is illuminated when ECM detects either malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. HO2S-1 heater malfunction.
  3. HO2S-1 heater circuit malfunction.
  1. DTC P0037: Heated Oxygen Sensor No. 2 - Heater Circuit - Low Input.
  2. DTC P0038: Heated Oxygen Sensor No. 2 - Heater Circuit - High Input.

DTC P0037 is set when Engine Control Module (ECM) detects Heated Oxygen Sensor No. 2 (HO2S-2) heater circuit voltage input is higher than 13.63 volts while HO2S-1 heater is ON. DTC P0038 is set when ECM detects HO2S-2 heater circuit voltage input is lower than 0.70 volt while HO2S-2 heater is ON. MIL is illuminated when ECM detects either malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. HO2S-2 heater malfunction.
  3. HO2S-2 heater circuit malfunction.

DTC is set when intake air flow measured by Mass Air Flow (MAF) sensor does not agree with intake air flow calculated by Engine Control Module (ECM) using manifold absolute pressure, barometric pressure and engine speed. MIL is illuminated when ECM detects malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. MAF sensor malfunction.
  3. MAF sensor circuit malfunction.
  4. Plugged or leaking air intake system.

DTC is set when Engine Control Module (ECM) detects Mass Air Flow (MAF) sensor output voltage is less than 0.3 volt for one second continuously with engine running. Possible causes are

  1. ECM malfunction.
  2. MAF sensor malfunction.
  3. MAF sensor circuit malfunction.

DTC is set when Engine Control Module (ECM) detects Mass Air Flow (MAF) sensor output voltage is more than 5 volts for 3 seconds continuously with ignition switch in ON position, or for one second with engine running. Possible causes are

  1. ECM malfunction.
  2. MAF sensor malfunction.
  3. MAF sensor circuit malfunction.
  1. DTC P0107: Manifold Absolute Pressure Sensor Circuit - Low Input.
  2. DTC P0108: Manifold Absolute Pressure Sensor Circuit - High Input.

DTC P0107 is set when after engine is at normal operating temperature and ignition is on, engine not running, less than .02 volts is detected for more than a predetermined time by ECM. MIL is illuminated when ECM detects malfunction during 2 consecutive drive cycles. DTC P0108 is set when after engine is at normal operating temperature and engine idling, more than 4.6 volts is detected for more than a predetermined time by ECM. MIL is illuminated when ECM detects either malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. MAP sensor malfunction.
  3. MAP sensor vacuum passage.

DTC is set when Engine Control Module (ECM) detects than intake air temperature variation is less than predetermined after engine is at operating condition. DTC is also set when intake air temperature is 14°F (-10°C) or less or 158°F (70°C) or more. MIL is illuminated when ECM detects malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. Intake Air Temperature (IAT) sensor malfunction.
  3. IAT sensor circuit malfunction (high resistance).

DTC is set when Engine Control Module (ECM) detects Intake Air Temperature (IAT) sensor voltage is lower than 0.16 volts for 5 seconds continuously (low voltage - low resistance - high intake air temperature). MIL is illuminated when ECM detects malfunction during first drive cycle. Possible causes are

  1. ECM malfunction.
  2. IAT sensor malfunction.
  3. IAT sensor circuit malfunction.

DTC is set when Engine Control Module (ECM) detects Intake Air Temperature (IAT) sensor voltage is more than 5 volts for 5 seconds continuously (high voltage - high resistance - low intake air temperature). MIL is illuminated when ECM detects malfunction during first drive cycle. Possible causes are

  1. ECM malfunction.
  2. IAT sensor malfunction.
  3. IAT sensor circuit malfunction.

DTC is set when Engine Control Module (ECM) detects Engine Coolant Temperature (ECT) variation is less than specified value. ECT fails to reach predetermined level after vehicle has been running for a predetermined time. MIL is illuminated when ECM detects malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. ECT sensor malfunction.
  3. ECT sensor circuit malfunction.
  4. Thermostat malfunction.

DTC is set when Engine Control Module (ECM) detects Engine Coolant Temperature (ECT) sensor input voltage is less than 0.16 volts for 5 seconds continuously, with engine running. High engine coolant temperature (low voltage - low resistance). MIL is illuminated when ECM detects malfunction during first drive cycle. Possible causes are

  1. ECM malfunction.
  2. ECT sensor malfunction.
  3. ECT sensor circuit malfunction.

DTC is set when Engine Control Module (ECM) detects Engine Coolant Temperature (ECT) sensor input voltage is less than 0.16 volts for 5 seconds continuously, with engine running. Low engine coolant temperature (high voltage - high resistance). MIL is illuminated when ECM detects malfunction during first drive cycle. Possible causes are

  1. ECM malfunction.
  2. ECT sensor malfunction.
  3. ECT sensor circuit malfunction.

DTC is set when Engine Control Module (ECM) detects throttle opening is to small (rationality-low) while engine is operating under high load and high engine speed. DTC is also set when ECM detects throttle opening is to large (rationality-high) while engine is operating under low load and low engine speed. MIL is illuminated when ECM detects malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. Throttle Position (TP) sensor malfunction.
  3. TP sensor circuit malfunction.

DTC is set when Engine Control Module (ECM) detects Throttle Position (TP) sensor voltage is less than 0.1 volt for one second. MIL is illuminated when ECM detects malfunction during first drive cycle. Possible causes are

  1. ECM malfunction.
  2. TP sensor malfunction.
  3. TP sensor circuit malfunction.

DTC is set when Engine Control Module (ECM) detects Throttle Position (TP) sensor voltage is more than 0.1 volt for one second. MIL is illuminated when ECM detects malfunction during first drive cycle. Possible causes are

  1. ECM malfunction.
  2. TP sensor malfunction.
  3. TP sensor circuit malfunction.

DTC is set when Engine Control Module (ECM) detects engine coolant temperature fails to reach predetermined level, allowing for closed loop operation, after vehicle has been driven for a specified time. MIL is illuminated when ECM detects malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. Engine Coolant Temperature (ECT) sensor malfunction.
  3. ECT sensor circuit malfunction.
  4. Thermostat malfunction.

DTC is set when Engine Control Module (ECM) detects engine coolant temperature is lower than 167°F (75°C), after vehicle has been driven under specified conditions. MIL is illuminated when ECM detects malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. Engine Coolant Temperature (ECT) sensor malfunction.
  3. ECT sensor circuit malfunction.
  4. Thermostat malfunction.
  1. DTC P0131: Heated Oxygen Sensor No. 1 Circuit - Low Input
  2. DTC P0132: Heated Oxygen Sensor No. 1 Circuit - High Input

DTC P0131 is set when Heated Oxygen Sensor No. 1 (HO2S-1) maximum output voltage is .06 volt or less and average minimum output voltage is .03 volt or less. DTC P0132 is set when HO2S-1 maximum output voltage is .74 volt or more and average minimum output voltage is .33 volt or more. MIL is illuminated when Engine Control Module (ECM) detects either malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. Fuel system malfunction.
  3. HO2S-1 malfunction.

DTC is set when time for Heated Oxygen Sensor No. 1 Circuit (HO2S-1) to change from lean to rich or from rich to lean is high. MIL is illuminated when Engine Control Module (ECM) detects malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. HO2S-1 malfunction.

DTC is set when Engine Control Module (ECM) detects Heated Oxygen Sensor No. 1 (HO2S-1) circuit voltage input is .45 volt or lower. MIL is illuminated when ECM detects malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. Fuel system malfunction.
  3. HO2S-1 malfunction.

DTC is set when Engine Control Module (ECM) detects maximum Heated Oxygen Sensor No. 2 (HO2S-2) output voltage is more than 2 volts for 20 seconds, or maximum HO2S-2 voltage is less than .35 volt for 8 minutes. MIL is illuminated when ECM detects malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. HO2S-2 malfunction.
  3. HO2S-2 circuit malfunction.
  1. DTC P0138: Heated Oxygen Sensor No. 2 Circuit - High Voltage.
  2. DTC P0140: Heated Oxygen Sensor No. 2 Circuit - No Activity Detected.

DTC P0138 is set when with engine running closed loop mode, average output voltage during specified time is too high, or with engine running closed loop mode, minimum output voltage during specified time is too high. MIL is illuminated when ECM detects malfunction during 2 consecutive drive cycles. DTC P0140 is set when with engine running closed loop mode, average output voltage during specified time is too low, or with engine running closed loop mode, maximum output voltage during specified time is too low. DTC P0140 is set when with engine running closed loop mode, average output voltage during specified time is too low, or with engine running closed loop mode, maximum output voltage during specified time is too low. MIL is illuminated when ECM detects either malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. Fuel system malfunction.
  3. HO2S-2 malfunction.
  1. DTC P0171: System Too Lean.
  2. DTC P0172: System Too Rich.

DTC P0171 is set when Engine Control Module (ECM) detects that total fuel trim is more than 33 percent. DTC P0172 is set when ECM detects that total fuel trim is less than -33 percent. MIL is illuminated when ECM detects either malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. Engine Coolant Temperature (ECT) sensor.
  3. Exhaust Gas Recirculation (EGR) system malfunction.
  4. Exhaust system leaks.
  5. Fuel level sensor malfunction.
  6. Heated Oxygen Sensor No. 1 (HO2S-1) malfunction.
  7. Incorrect fuel pressure.
  8. Mass Air Flow (MAF) sensor malfunction.
  9. Vacuum leaks.
  1. DTC P0300: Random Misfire Detected.
  2. DTC P0301: Cylinder No. 1 Misfire Detected.
  3. DTC P0302: Cylinder No. 2 Misfire Detected.
  4. DTC P0303: Cylinder No. 3 Misfire Detected.
  5. DTC P0304: Cylinder No. 4 Misfire Detected.

DTC P0300 sets when misfire which causes catalyst to overheat during 200 crankshaft revolutions is detected at 2 or more cylinders (MIL flashes as long as misfire occurs). When ECM detects a misfire (misfire rate per 1000 revolutions) which will not cause damage to TWC, but could cause exhaust emission deterioration. ECM will illuminate MIL when it detects malfunction during 2 consecutive drive cycles.

DTCs P0301, P0302, P0303 or P0304 sets when misfire which causes catalyst to overheat during 200 crankshaft revolutions is detected at any individual cylinder (MIL flashes as long as misfire occurs). When ECM detects a misfire (misfire rate per 1000 revolutions) which will not cause damage to TWC, but could cause exhaust emission deterioration. ECM will illuminate MIL when it detects malfunction during 2 consecutive drive cycles. Possible causes are

  1. EGR system malfunction.
  2. Fuel injector malfunction.
  3. Fuel level sensor malfunction.
  4. Ignition system malfunction.
  5. Incorrect engine compression.
  6. Incorrect fuel pressure.
  7. Incorrect valve clearance.
  8. Incorrect valve timing.
  9. Intake system vacuum leaks.
  1. DTC P0327: Knock Sensor Circuit - Low Input.
  2. DTC P0328: Knock Sensor Circuit - High Input.

DTC P0327 is set when Engine Control Module (ECM) detects that Knock sensor voltage is 0.9 volt or less for 2 seconds. DTC P0328 is set when ECM detects that Knock sensor voltage is 3.98 volts or more for 2 seconds. MIL is illuminated when ECM detects either malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. Knock sensor malfunction.
  3. Knock sensor circuit malfunction.

DTC is set when Engine Control Module (ECM) detects no Crankshaft Position (CKP) sensor input voltage (20 pulses) for 3 seconds with engine running. Possible causes are

  1. CKP sensor malfunction.
  2. CKP sensor circuit malfunction.
  3. CKP sensor reluctor wheel malfunction.
  4. ECM malfunction.

DTC is set when Engine Control Module (ECM) detects no Camshaft Position (CMP) sensor reference signal input voltage when engine start signal is input. DTC also is set if number of pulses produced by the CMP sensor is out of specification. Possible causes are

  1. CMP sensor malfunction.
  2. CMP sensor circuit malfunction.
  3. ECM malfunction.
  4. Engine start signal circuit malfunction.
  1. DTC P0401: Exhaust Gas Recirculation (EGR) - Insufficient Flow Detected.
  2. DTC P0402: EGR - Excessive Flow Detected.

DTC P0401 is set when Engine Control Module (ECM) detects there is a difference in intake manifold absolute pressure, when EGR valve is opened and when EGR valve is closed is less than specified value.

DTC P0402 is set when ECM detects there is a difference in intake manifold absolute pressure, when EGR valve is opened and when EGR valve is closed is more than specified value. MIL is illuminated when ECM detects either malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. EGR valve malfunction.
  3. EGR passage restricted.
  4. Manifold Absolute Pressure (MAP) sensor malfunction.

DTC is set when Engine Control Module (ECM) commands EGR valve to turn OFF and detects low voltage at EGR stepper motor for a predetermined amount of time continuously. MIL is illuminated when ECM detects malfunction during one drive cycle. Possible causes are

  1. ECM malfunction.
  2. EGR circuit malfunction.
  3. EGR valve malfunction.

DTC is set when Engine Control Module (ECM) detects that value from HO2S-2 becomes closer to value from HO2S-1. MIL is illuminated when ECM detects malfunction during 2 consecutive drive cycles. Possible causes are

  1. Catalytic converter malfunction.
  2. Exhaust system malfunction.
  3. Fuel system malfunction.
  4. HO2S-2 malfunction.

DTC P0441 is set when Engine Control Module (ECM) detects changes in both calculated load value and Idle Air Control (IAC) flow rate are lower than specification while EVAP purge rate is changed. MIL is illuminated when ECM detects malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. EVAP canister plugged.
  3. EVAP Canister Purge Valve (EVAP-CPV) malfunction.
  4. EVAP-CPV circuit malfunction.
  5. EVAP control system vacuum hoses malfunction.
  1. DTC P0442: EVAP System - Small Leak Detected.
  2. DTC P0455: EVAP System - Large Leak Detected.

DTC P0442 is set when fuel tank pressure increases more than specified value, a small leak in EVAP system is detected.

DTC P0455 is set when fuel tank pressure change is less than specified value, a large leak in EVAP system is detected. MIL is illuminated when ECM detects either malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. EVAP canister.
  3. EVAP-CVV.
  4. EVAP control system circuits malfunction.
  5. EVAP control system vacuum hoses malfunction.
  6. Fuel level sensor malfunction.
  7. Fuel tank component malfunction.
  8. Fuel Tank Pressure (FTP) sensor malfunction.
  9. Leaking fuel pump assembly seal on fuel tank.
  10. Missing, loose or malfunctioning fuel filler cap, or leak from cap gasket.

DTC sets when EVAP-Canister Purge Valve (EVAP-CPV) output voltage is low when Engine Control Module (ECM) commands EVAP purge valve closed. MIL is illuminated when ECM detects malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. EVAP-CPV malfunction.
  3. EVAP-CPV circuit malfunction.

DTC sets when EVAP Canister Vent Valve (EVAP-CVV) output voltage is low while Engine Control Module (ECM) commands EVAP-CVV to open. MIL is illuminated when ECM detects malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. EVAP-CVV malfunction.
  3. EVAP-CVV circuit malfunction.

DTC sets when Engine Control Module (ECM) detects EVAP Canister Vent Valve (EVAP-CVV) output voltage is different from command signal (circuit open or short). MIL is illuminated when ECM detects malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. EVAP-CVV malfunction.
  3. EVAP-CVV circuit malfunction.

DTC is set when Engine Control Module (ECM) detects Fuel Tank Pressure (FTP) sensor output voltage is out of range with engine running. MIL is illuminated when PCM detects malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. FTP sensor malfunction.
  3. FTP sensor circuit malfunction.
  4. FTP sensor vent hole and pressure passage plugged.
  1. DTC P0452: EVAP Fuel Tank Pressure Sensor - Low Input.
  2. DTC P0453: EVAP Fuel Tank Pressure Sensor - High Input.

DTC P0452 is set when Engine Control Module (ECM) detects Fuel Tank Pressure (FTP) sensor output voltage is lower than .5 volt.

DTC P0453 is set when Engine Control Module (ECM) detects Fuel Tank Pressure (FTP) sensor output voltage is higher than 4.5 volts. MIL is illuminated when ECM detects either malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. EVAP control system hoses malfunction (clogged).
  3. FTP sensor malfunction.
  4. FTP sensor circuit malfunction.

DTC P0456 is set when fuel tank pressure increases more than specified value, a very small leak in EVAP system is detected. Possible causes are

  1. ECM malfunction.
  2. EVAP canister.
  3. EVAP canister control valve.
  4. EVAP control system circuits malfunction.
  5. EVAP control system vacuum hoses malfunction.
  6. Fuel level sensor malfunction.
  7. Fuel tank component malfunction.
  8. Fuel Tank Pressure (FTP) sensor malfunction.
  9. Leaking fuel pump assembly seal on fuel tank.
  10. Missing, loose or malfunctioning fuel filler cap, or leak from cap gasket.

DTC is set when Engine Control Module (ECM) detects a change in fuel level signal is less than predetermined when fuel injector volume is more than predetermined. MIL is illuminated when ECM detects malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. Fuel level gauge malfunction.
  3. Fuel level sensor malfunction.
  4. Fuel level sensor circuit malfunction.

DTC is set when Engine Control Module (ECM) detects fuel level sensor voltage is more than specified value. MIL is illuminated when ECM detects malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. Fuel level sensor malfunction.
  3. Fuel level sensor circuit malfunction.

DTC is set when Engine Control Module (ECM) detects fuel level sensor voltage is more than specified value. MIL is illuminated when ECM detects malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. Fuel level sensor malfunction.
  3. Fuel level sensor circuit malfunction.

DTC P0496 is set when Engine Control Module (ECM) detects fuel tank internal pressure decreasing in fuel tank is more than specified after ECM has commanded EVAP canister purge valve closed. MIL is illuminated when ECM detects malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. EVAP canister purge valve (CPV) malfunction.
  3. Fuel Tank Pressure (FTP) sensor malfunction.

DTC is set when Engine Control Module (ECM) detects no vehicle speed signal input with vehicle decelerating (fuel cut) for more than 5 seconds. Possible causes are

  1. ECM malfunction.
  2. Cruise control module malfunction (If equipped).
  3. Speedometer malfunction.
  4. VSS malfunction.
  5. VSS circuit malfunction.
  6. VSS drive gear or driven gear malfunction.
  1. DTC P0506: Idle Air Control - RPM Lower Than Expected.
  2. DTC P0507: Idle Air Control - RPM Higher Than Expected.

DTC P0506 is set when Engine Control Module (ECM) detects engine idle speed is 100 RPM or more lower than predetermined for 20 seconds or more, continuously. DTC P0507 is set when Engine Control Module (ECM) detects engine idle speed is 200 RPM or more higher than predetermined for 20 seconds or more, continuously. MIL is illuminated when ECM detects either malfunction during 2 consecutive drive cycles. Possible causes are

  1. IAC valve malfunction.
  2. IAC valve circuit malfunction.
  3. Air intake system plugged, leaking or fast idle control system malfunction.

DTC is set when a data write error occurred. Possible cause is an Engine Control Module (ECM) malfunction.

DTC P0616 is set when Engine Control Module (ECM) detects that engine starts even though vehicle is at a stop and start signal is not being inputted. MIL is illuminated when ECM detects malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. Engine start signal circuit.

DTC is set when Engine Control Module (ECM) detects that engine start signal is being inputted continuously while engine is running. MIL is illuminated when ECM detects malfunction during 2 consecutive drive cycles. Possible causes are

  1. Engine start signal circuit malfunction.
  2. ECM malfunction.
  3. Ignition switch.

DTC is set when Engine Control Module (ECM) detects incorrect voltage at ECM back-up power supply with engine running. Battery voltage is supplied so that diagnostic trouble code memory values are not lost when ignition is turned off. Possible cause are

  1. Battery voltage supply circuit malfunction.
  2. ECM malfunction.

DTC is set when Engine Control Module (ECM) detects variation in temperature signal of tank pressure and temperature sensor is less than specified value even after vehicle has been running for a specified time from a cold engine start. MIL is illuminated when ECM detects malfunction during 2 consecutive drive cycles. Possible cause are

  1. ECM malfunction.
  2. ECT sensor circuit malfunction.
  3. Fuel tank pressure and temperature sensor malfunction.
  4. Fuel tank pressure and temperature sensor circuit malfunction.

DTC is set when Engine Control Module (ECM) detects high fuel vapor temperature (low voltage and low resistance). Possible cause are

  1. ECM malfunction.
  2. Fuel tank pressure and temperature sensor malfunction.
  3. Fuel tank pressure and temperature sensor circuit shorted to an other circuit or ground.

DTC is set when Engine Control Module (ECM) detects low fuel vapor temperature (high voltage and high resistance). Possible cause are

  1. Fuel tank pressure and temperature sensor malfunction.
  2. Fuel tank pressure and temperature sensor circuit open or shorted to an other circuit.
  3. ECM malfunction.

DTC P2227 is set when Engine Control Module (ECM) detects barometric pressure calculated using Manifold Absolute Pressure (MAP) sensor does not match barometric pressure sensor output voltage during engine deceleration.

DTC P2228 is set when Engine Control Module (ECM) detects that barometric pressure sensor is less than specification.

DTC P2229 is set when Engine Control Module (ECM) detects that barometric pressure sensor is more than specification. MIL is illuminated when ECM detects malfunction during 2 consecutive drive cycles. Possible causes are

  1. ECM malfunction.
  2. Barometric pressure sensor (in ECM) malfunction.
  3. MAP sensor malfunction.

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