Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
SYS.OK|MANUAL.DB● LIVE
HOMESERVICE MANUALSMAZDA20066 I, 4D SEDAN, AUTOMATICREPAIR AND DIAGNOSIS (SINGLE PAGE)ENGINE PERFORMANCEENGINE CONTROL SYSTEMSENGINE CONTROL SYSTEM (L3)PCM INSPECTIONWITHOUT USING THE SST
2006 Mazda 6 i, 4D Sedan, Automatic
Without Using the SST
2006 Mazda 6 i, 4D Sedan, AutomaticSECTION Without Using the SST
CAUTION:
- The PCM terminal voltages vary with change in measuring conditions and vehicle conditions. Always carry out a total inspection of the input systems, output systems, and PCM to determine the cause of trouble. Otherwise, a wrong diagnosis will be made.
- Measure the voltage at each terminal.
- If any incorrect voltage is detected, inspect the related system(s), wiring harnesses and connector(s) referring to the Action column in the terminal voltage table.
Terminal voltage table (Reference)
PCM REFERENCE CHART
| Terminal | Signal | Connected to | Test condition | Voltage (V) | Inspection item | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1A | Security light control | Security light | IG SW ON | Approx. 11.3 |
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| 1B | Starter relay control | Starter relay | Under any condition | Below 1.0 |
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| 1C | - | - | - | - | - | |||||||||||
| 1D | Clutch operation(1) | CPP switch | Clutch pedal depressed | Below 1.0 |
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| Clutch pedal released | B+ | |||||||||||||||
| 1E | Coil (Immobilizer system) | Coil | Because this terminal is for communication, good/no good judgment by terminal voltage is not possible. |
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| 1F | Coil (Immobilizer system) | Coil | Because this terminal is for communication, good/no good judgment by terminal voltage is not possible. |
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| 1G | - | - | - | - | - | |||||||||||
| 1H | Fuel pump control | Fuel pump relay | Ignition switch ON | B+ |
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| Cranking | Below 1.0 | |||||||||||||||
| Idle | Below 1.0 | |||||||||||||||
| 1I | A/C | A/C relay | A/C operating | Below 1.0 |
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| A/C not operating | B+ | |||||||||||||||
| 1J | A/C compressor load | Refrigerant pressure switch (middle) | A/CON | Refrigerant pressure is more than 1.52 MPa {15.5 kgf/cm2 , 220 psi} | Below 1.0 |
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| Refrigerant pressure is less than 1.23 M Pa {12.5 kgf/cm2 , 178 psi} | B+ | |||||||||||||||
| 1K | VAD control | VAD solenoid valve | Idle after warm up | Engine speed less than 5,800 RPM | B+ |
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| Engine speed more than 5,800 RPM | Below 1.0 | |||||||||||||||
| 1L | - | - | - | - | - | |||||||||||
| 1M | Cooling fan control (Main) | Cooling fan relay No.1 | Idling | ECT less than 100°C {212°F} | B+ |
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| A/C operating | Below 1.0 | |||||||||||||||
| 1N | Cooling fan control (Add) | Cooling fan relay No.4 | Idling | ECT less than 100°C {212°F} | B+ |
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| A/C operating | Below 1.0 | |||||||||||||||
| 1O | VSS output signal | VSS |
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| 1P | MAF sensor GND | MAF/IAT sensor | Under any condition | Below 1.0 |
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| 1Q | Main relay control | Main relay | Ignition switch OFF | B+ |
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| Ignition switch ON | Below 1.0 | |||||||||||||||
| 1R | Cooling fan control (Transfer) | Cooling fan relay No.2 or No.3 | Idling | ECT less than 100°C {212°F} | B+ |
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| A/C operating | Below 1.0 | |||||||||||||||
| 1S | - | - | - | - | - | |||||||||||
| 1T | - | - | - | - | - | |||||||||||
| 1U | EVAP system leak detection pump (pump) | EVAP system leak detection pump | Ignition switch ON | B+ |
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| Idle | B+ | |||||||||||||||
| 1V | EVAP system leak detection pump (solenoid) | EVAP system leak detection pump | IG SW ON | B+ |
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| Idle | B+ | |||||||||||||||
| 1W | - | - | - | - | - | |||||||||||
| 1X | Neutral position(1) | Neutral switch | Shift lever is at neutral position | Below 1.0 |
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| Shift lever is not at neutral position | B+ | |||||||||||||||
| 1Y | - | - | - | - | - | |||||||||||
| 1Z | - | - | - | - | - | |||||||||||
| 1AA | - | - | - | - | - | |||||||||||
| 1AB | Brake 1 | Brake switch | Brake pedal depressed | B+ |
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| Brake pedal released | Below 1.0 | |||||||||||||||
| 1AC | - | - | - | - | - | |||||||||||
| 1AD | - | - | - | - | - | |||||||||||
| 1AE | - | - | - | - | - | |||||||||||
| 1AF | Brake 2 | Brake switch | Brake pedal depressed | B+ |
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| Brake pedal released | Below 1.0 | |||||||||||||||
| 1AG | - | - | - | - | - | |||||||||||
| 1AH | - | - | - | - | - | |||||||||||
| 1AI | CAN (L) | Instrument cluster, ABS/TCS HU/CM, TCM | Because this terminal is for CAN, good/no good judgment by terminal voltage is not possible. |
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| 1AJ | Constant voltage (VREF) | APP sensor | Ignition switch ON | Approx. 5.0 |
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| 1AK | MAF | MAF sensor | Ignition switch ON | Approx. 0.7 |
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| Idle (after warm up) | MTX | 1.15-1.28 | ||||||||||||||
| ATX | 1.18-1.31 | |||||||||||||||
| 1AL | Constant voltage (VREF) | APP sensor | Ignition switch ON | Approx. 5.0 |
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| 1AM | CAN (H) | Instrument cluster, ABS HU/CM, TCM | Because this terminal is for CAN, good/no good judgment by terminal voltage is not possible. |
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| 1AN | - | - | - | - | - | |||||||||||
| 1AO | APP sensor 1 | APP sensor | IG SW ON | APP released | 1.55-1.62 |
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| APP depressed | 3.49-4.09 | |||||||||||||||
| 1AP | APP sensor 2 | APP sensor | IG SW ON | APP released | 1.01-1.07 |
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| APP depressed | 2.94-3.54 | |||||||||||||||
| 1AQ | Cruise control switch(2) | Cruise control switch | IG SW ON | Depressing ON/OFF | Approx. 0 |
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| Depressing CANCEL | Approx. 1.2 | |||||||||||||||
| Depressing SET/COAST | Approx. 3.2 | |||||||||||||||
| Depressing Res/ACCEL | Approx. 4.2 | |||||||||||||||
| Others | Approx. 5.0 | |||||||||||||||
| 1AR | IAT sensor GND | MAF/IAT sensor | Under any condition | Below 1.0 |
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| 1AS | APP sensor GND | APP sensor | Under any condition | Below 1.0 |
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| 1AT | IAT | MAF/IAT sensor | IG SW ON | IAT 0°C {32°F} | Approx. 3.43 |
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| IAT 20°C {68°F} | Approx. 2.38 | |||||||||||||||
| IAT 40°C {104°F} | Approx. 1.49 | |||||||||||||||
| IAT 60°C {140°F} | Approx. 0.89 | |||||||||||||||
| IAT 80°C {176°F} | Approx. 0.53 | |||||||||||||||
| IAT 100°C {212°F} | Approx. 0.33 | |||||||||||||||
| 1AU | A/C | A/C relay | Idle | A/C operating | Below 1.0 |
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| A/C not operating | B+ | |||||||||||||||
| 1AV | APP sensor GND | APP sensor | Under any condition | Below 1.0 |
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| 1AW | Back-up power supply(3) | Main relay | Under any condition | B+ |
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| 1AX | Throttle actuator control power supply | Drive-by-wire relay | Ignition switch OFF (after 90 s) | Below 1.0 |
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| Ignition switch ON | B+ | |||||||||||||||
| 1AY | Ignition switch (IG1) | Ignition switch | Ignition switch OFF | Below 1.0 |
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| Ignition switch ON | B+ | |||||||||||||||
| 1AZ | GND | Ground | Under any condition | Below 1.0 |
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| 1BA | Back-up power supply | Battery (positive terminal) | Under any condition | B+ |
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| 1BB | GND | Ground | Under any condition | Below 1.0 |
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| 1BC | Sensor GND | HO2S (rear) | Under any condition | Below 1.0 |
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| 1BD | GND | Ground | Under any condition | Below 1.0 |
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| 1BE | Main relay control | Main relay | Ignition switch OFF | B+ |
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| Ignition switch ON | Below 1.0 | |||||||||||||||
| 1BF | Throttle actuator control power supply | Drive-by-wire relay | Ignition switch OFF (after 90 s) | Below 1.0 |
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| Ignition switch ON | B+ | |||||||||||||||
| 1BG | Sensor GND(3) | HO2S (middle) | Under any condition | Below 1.0 |
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| 1BH | GND | Ground | Under any condition | Below 1.0 |
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| 2A | Throttle actuator control (+) | Throttle body | Ignition switch ON | B+ |
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| 2B | Throttle actuator control (-) | Throttle body | Idle (after warm up) | 3.5-5.5 |
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| 2C | Purge control | Purge solenoid valve |
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| 2D | - | - | - | - | - | |||||||||||
| 2E | OCV control | OCV |
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| 2F | - | - | - | - | - | |||||||||||
| 2G | EGR valve #2 coil control | EGR valve (terminal A) | Ignition switch ON | B+ |
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| Idle | B+ | |||||||||||||||
| 2H | EGR valve #4 coil control | EGR valve (terminal F) | Ignition switch ON | Below 1.0 |
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| Idle | Below 1.0 | |||||||||||||||
| 2I | Variable tumble control | Variable tumble solenoid valve | ECT more than 60°C {140°F} while idling. | B+ |
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| ECT less than 60°C {140°F} and engine speed less than 3,750 RPM | Below 1.0 | |||||||||||||||
| 2J | Variable intake air control | Variable intake air solenoid valve | Engine speed: more than 4,500 RPM | B+ |
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| Engine speed: less than 4,500 RPM | Below 1.0 | |||||||||||||||
| 2K | EGR valve #1 coil control | EGR valve (terminal E) | Ignition switch ON | Below 1.0 |
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| Idle | Below 1.0 | |||||||||||||||
| 2L | EGR valve #3 coil control | EGR valve (terminal B) | Ignition switch ON | B+ |
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| idle | B+ | |||||||||||||||
| 2M | VSS (-)(4) | VSS |
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| 2N | VSS (+)(4) | VSS |
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| 20 | - | - | - | - | - | |||||||||||
| 2P | - | - | - | - | - | |||||||||||
| 2Q | HO2S (rear) | HO2S (rear) | Ignition switch ON | Approx. 0 |
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| Idle (after warm up) | 01.0 | |||||||||||||||
| 2R | HO2S (middle)(3) | HO2S (middle) | Ignition switch ON | Approx. 0 |
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| Idle (after warm up) | 0<==>0.1 | |||||||||||||||
| 2S | CMP signal | CMP sensor |
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| 2T | PSP | PSP switch | Idle | Steering wheel at straight ahead position | B+ |
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| While turning steering wheel | Below 1.0 | |||||||||||||||
| 2U | Knocking (+) | Knock sensor | Ignition switch ON (Use digital type voltmeter, because measurement voltage will be detected less than true voltage when using analog type voltmeter) | Approx. 4.3 |
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| 2V | Knocking (-) | Knock sensor | Ignition switch ON (Use digital type voltmeter, because measurement voltage will be detected less than true voltage when using analog type voltmeter) | Below 1.0 |
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| 2W | CKP signal | CKP sensor |
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| 2X | HO2S (front) shield | HO2S (front) | Under any condition | Below 1.0 |
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| 2Y | - | - | - | - | - | |||||||||||
| 2Z | HO2S (front) sensor GND(3) | HO2S (front) | Under any condition | Below 1.0 |
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| HO2S (front)(5) | HO2S (front) | Ignition switch ON | Approx. 6.19 |
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| Ignition switch OFF (after 90 s) | Below 1.0 | |||||||||||||||
| Idle (after warm up) | Approx. 4.1 | |||||||||||||||
| 2AA | - | - | - | - | - | |||||||||||
| 2AB | - | - | - | - | - | |||||||||||
| 2AC | HO2S (front)(5) | HO2S (front) | Idle (after warm up): Approx. 0 mA | - |
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| 2AD | HO2S (front)(3) | HO2S (front) |
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| HO2S (front)(5) | HO2S (front) |
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| 2AE | Variable tumble shutter valve monitor | Variable tumble shutter valve switch | ECT less than 62°C {144°F} while engine speed less than 3,750 RPM | Approx. 5.0 |
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| ECT more than 62°C {144°F} or engine speed 3,750 RPM or more | Below 1.0 | |||||||||||||||
| 2AF | - | - | - | - | - | |||||||||||
| 2AG | Manifold absolute pressure | MAP sensor | Ignition switch ON (Engine OFF) at sea level | Approx. 4.1 |
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| 2AH | ECT | ECT sensor | IG SW ON | IAT 20°C {68°F} | 3.04-3.14 |
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| IAT 40°C {104°F} | 2.09-2.21 | |||||||||||||||
| IAT 60°C {140°F} | 1.29-1.39 | |||||||||||||||
| IAT 80°C {176°F} | 0.76-0.83 | |||||||||||||||
| IAT 100°C {212°F} | 0.45-0.49 | |||||||||||||||
| 2AI | Generator field coil control | Generator (terminal D) |
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| 2AJ | Generator output voltage | Generator (terminal P) |
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| 2AK | TP (No. 1) | TP sensor No. 1 | Ignition switch ON | APP released | 0.4-0.6 |
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| APP depressed | 4.4-4.7 | |||||||||||||||
| 2AL | TP (No. 2) | TP sensor No. 2 | Ignition switch ON | APP released | 4.4-4.6 |
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| APP depressed | 0.3-0.6 | |||||||||||||||
| 2AM | CMP power | CMP sensor | Ignition switch ON | B+ |
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| Ignition switch OFF (after 90 s) | Below 1.0 | |||||||||||||||
| 2AN | - | - | - | - | - | |||||||||||
| 2AO | Constant voltage (VREF) | TP sensor | Under any condition | Approx. 5.0 |
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| 2AP | TP sensor GND | TP sensor | Ignition switch ON | Below 1.0 |
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| 2AQ | CKP power | CKP sensor | Ignition switch ON | B+ |
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| Ignition switch OFF | Below 1.0 | |||||||||||||||
| 2AR | - | - | - | - | - | |||||||||||
| 2AS | - | - | - | - | - | |||||||||||
| 2AT | IGT4 | Ignition coil (No.4 cylinder) |
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| 2AU | Constant voltage (VREF) | MAP sensor | Ignition switch ON | Approx. 5.0 |
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| 2AV | - | - | - | - | - | |||||||||||
| 2AW | IGT2 | Ignition coil (No.2 cylinder) |
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| 2AX | IGT3 | Ignition coil (No.3 cylinder) |
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| 2AY | Sensor GND | ECT sensor, MAP sensor, variable tumble shutter valve switch | Under any condition | Below 1.0 |
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| 2AZ | Fuel injection (#4) | Fuel injector No.4 |
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| 2BA | IGT1 | Ignition coil (No.1 cylinder) |
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| 2BB | Fuel injection (#1) | Fuel injector No.1 |
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| 2BC | Fuel injection (#2) | Fuel injector No.2 |
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| 2BD | Fuel injection (#3) | Fuel injector No.3 |
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| 2BE | HO2S (rear) heater control | HO2S (rear) heater |
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| 2BF | HO2S (middle) heater control | HO2S (middle) heater | Engine speed: less than 4,000 RPM | B+ |
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| Engine speed: more than 4,000 RPM | Below 1.0 | |||||||||||||||
| 2BG | HO2S (front) heater control | HO2S (front) heater |
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| 2BH | - | - | - | - | - | |||||||||||
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RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.