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.
2012 Kia Optima SXFACTORY OEM SERVICE PROCEDURE
ECM Terminal Input/Output signal
Connector (CHTG-AG)
PIN DESCRIPTION CHART
| Pin No. | Description | Condition | Type | Level |
|---|---|---|---|---|
| 1 | Ignition Coil (Cylinder #2) control output (Without Smart Key) | Engine Running | Pulse | Vpeak = 360 ~ 440V |
| Ignition Coil (Cylinder #3) control output (With Smart Key) | 125 (333Hz at idle) | |||
| 2 | - | |||
| 3 | - | |||
| 4 | - | |||
| 5 | ETC Motor (+) control output | Engine Running | Pulse | High: Battery Voltage |
| Low: Max.1.0V | ||||
| 6 | ETC Motor (-) control output | Engine Running | Pulse | High: Battery Voltage |
| Low: Max.1.0V | ||||
| 7 | - | |||
| 8 | - | |||
| 9 | - | |||
| 10 | - | |||
| 11 | - | |||
| 12 | Sensor power (+5V) | IG OFF | DC | Max. 0.5V |
| IG ON | 4.75 ~ 5.25V | |||
| 13 | - | |||
| 14 | Heated Oxygen Sensor (HO2S) (Bank 1/Sensor 2) signal input | Idle | DC | Rich : 0.6 ~ 1.0V |
| Lean : Max 0.4V | ||||
| 15 | - | |||
| 16 | Electric Waste Gate Actuator (EWGA) Feed beck signal | |||
| 17 | CVVT Oil Temperature Sensor (OTS) signal input | |||
| 18 | Manifold Absolute Pressure Sensor (MAPS)#2 signal input | |||
| 19 | - | |||
| 20 | Fuel Tank Pressure Sensor (FTPS) signal input | Idle | Analog | -0.3 ~ 5.2V |
| 21 | Electric Waste Gate Actuator (EWGA) DC Motor output (-) | |||
| 22 | Ignition Coil (Cylinder #4) control output (Without Smart Key) | Engine Running | Pulse | Vpeak = 360 ~ 440V |
| Ignition Coil (Cylinder #1) control output (With Smart Key) | 125 (333Hz at idle) | |||
| 23 | - | |||
| 24 | - | |||
| 25 | - | |||
| 26 | - | |||
| 27 | - | |||
| 28 | - | |||
| 29 | - | |||
| 30 | - | |||
| 31 | - | |||
| 32 | - | |||
| 33 | Sensor power (+5V) | IG OFF | DC | Max. 0.5V |
| IG ON | 4.75 ~ 5.25V | |||
| 34 | - | |||
| 35 | Sensor ground | Idle | DC | -0.3 ~ 0.5V |
| 36 | - | |||
| 37 | Sensor ground | |||
| 38 | - | |||
| 39 | Rail Pressure Sensor (RPS) signal input | Idle | Analog | -0.3 ~ 5.2V |
| 40 | - | |||
| 41 | Sensor ground | Idle | DC | -0.3 ~ 0.5V |
| 42 | Electric Waste Gate Actuator (EWGA) DC Motor output (+) | |||
| 43 | - | |||
| 44 | - | |||
| 45 | - | |||
| 46 | - | |||
| 47 | - | |||
| 48 | - | |||
| 49 | - | |||
| 50 | - | |||
| 51 | - | |||
| 52 | - | |||
| 53 | - | |||
| 54 | Sensor ground | Idle | DC | -0.3 ~ 0.5V |
| 55 | Sensor ground | Idle | DC | -0.3 ~ 0.5V |
| 56 | Sensor ground | Idle | DC | -0.3 ~ 0.5V |
| 57 | Immobilizer communication line | |||
| 58 | Sensor ground | |||
| 59 | Intake Air Temperature Sensor (IATS) signal input | Idle | Analog | 0 ~ 5.0V (2.55V at Idle) |
| 60 | Sensor ground | Idle | DC | -0.3 ~ 0.5V |
| 61 | Sensor ground | Idle | DC | -0.3 ~ 0.5V |
| 62 | Sensor ground | Idle | DC | -0.3 ~ 0.5V |
| 63 | Engine Coolant Temperature Sensor (ECTS) signal input | Idle | Analog | 0.5 ~ 4.5V (1.02V at Idle) |
| 64 | Ignition Coil (Cylinder #3) control output (Without Smart Key) | Engine Running | Pulse | Vpeak = 360 ~ 440V |
| Ignition Coil (Cylinder #2) control output (With Smart Key) | 125 (333Hz at idle) | |||
| 65 | - | |||
| 66 | - | |||
| 67 | - | |||
| 68 | - | |||
| 69 | - | |||
| 70 | - | |||
| 71 | - | |||
| 72 | - | |||
| 73 | - | |||
| 74 | - | |||
| 75 | Throttle Position Sensor (TPS) 2 signal input | C.T | Analog | 4.2 ~ 5.0V |
| W.O.T | 3.3 ~ 3.8V | |||
| 76 | Accelerator Position Sensor (APS) 2 signal input | C.T | Analog | Max. 1.0V |
| W.O.T | 1.5 ~ 3.0V | |||
| 77 | Accelerator Position Sensor (APS) 1 signal input | C.T | Analog | Max. 1.0V |
| W.O.T | Min. 4.0V | |||
| 78 | - | |||
| 79 | - | |||
| 80 | Sensor ground | Idle | DC | -0.3 ~ 0.5V |
| 81 | Sensor ground | |||
| 82 | Manifold Absolute Pressure Sensor (MAPS) signal input | Idle | Analog | 0.8 ~ 1.6V (1.37V at Idle) |
| 83 | Rc/Rp (Pump Cell Voltage) | Idle | Analog | Normal: 450±50 mV Rich: Max. Normal+150 mV Lean: Min. Normal-150 mV |
| 84 | VS-/IP-(Common Ground for VS, IP) | Idle | Analog | Reference for V_IP, V_N |
| 85 | Ignition Coil (Cylinder #1) control output (Without Smart Key) | Engine Running | Pulse | Vpeak = 360 ~ 440V |
| Ignition Coil (Cylinder #4) control output (With Smart Key) | 125 (333Hz at idle) | |||
| 86 | - | |||
| 87 | - | |||
| 88 | - | |||
| 89 | - | |||
| 90 | - | |||
| 91 | - | |||
| 92 | - | |||
| 93 | - | |||
| 94 | - | |||
| 95 | - | |||
| 96 | Throttle Position Sensor (TPS) 1 signal input | C.T | Analog | 0.3 ~ 0.9V |
| W.O.T | 1.5 ~ 3.0V | |||
| 97 | Sensor power (+5V) | IG OFF | DC | Max. 0.5V |
| IG ON | 4.75 ~ 5.25V | |||
| 98 | Sensor power (+5V) | IG OFF | DC | Max. 0.5V |
| IG ON | 4.75 ~ 5.25V | |||
| 99 | - | |||
| 100 | - | |||
| 101 | A/C Pressure Transducer (APT) signal input | |||
| 102 | - | |||
| 103 | Sensor power (+5V) | IG OFF | DC | Max. 0.5V |
| IG ON | 4.75 ~ 5.25V | |||
| 104 | Rc (Compensative Resistance) | Idle | Analog | |Rc-Rc/Rp|<±0.1V |
| 105 | VS+ (NERNST Cell Voltage) | Idle | Analog | Normal: 450±50 mV Rich: Max. Normal+150 mV Lean: Min. Normal-150 mV |
Connector (CHTG-BG)
PIN DESCRIPTION CHART
| Pin No. | Description | Condition | Type | Level |
|---|---|---|---|---|
| 1 | ECM ground | Idle | DC | -0.3 ~ 0.5V |
| 2 | ECM ground | Idle | DC | -0.3 ~ 0.5V |
| 3 | Battery power (B+) | IG OFF | DC | Max. 1.0V |
| IG ON | Battery Voltage | |||
| 4 | ECM ground | Idle | DC | -0.3 ~ 0.5V |
| 5 | Battery power (B+) | IG OFF | DC | Max. 1.0V |
| IG ON | Battery Voltage | |||
| 6 | Battery power (B+) | IG OFF | DC | Max. 1.0V |
| IG ON | Battery Voltage | |||
| 7 | - | |||
| 8 | Crankshaft Position Sensor (CKPS) signal input | Engine Running | Pulse | High : 4.5 ~ 5.5V |
| Low : -0.3 ~ 0.5V | ||||
| Frequency: 850Hz (Idle), 3, 000Hz (3, 000 RPM) | ||||
| 9 | - | |||
| 10 | Brake Switch 2 signal input | Brake OFF | DC | Battery Voltage |
| Brake ON | Max. 0.5V | |||
| 11 | - | |||
| 12 | - | |||
| 13 | - | |||
| 14 | Electrical load (wiper) signal input | |||
| 15 | Electrical load signal input (FR) | Lamp OFF | DC | Battery Voltage |
| Lamp ON | -0.3 ~ 0.5V | |||
| 16 | Alternator PWM signal output (COM) | Idle | Pulse | High: Battery Voltage |
| Low: Max. 1.5V | ||||
| Frequency: 125Hz | ||||
| 17 | - | |||
| 18 | Cooling Fan Relay (High) control output | Relay OFF | DC | Battery Voltage |
| Relay ON | Max. 1.0V | |||
| 19 | Immobilizer Lamp control output | Lamp OFF | DC | Battery Voltage |
| Lamp ON | -0.3 ~ 1.2V | |||
| 20 | - | |||
| 21 | - | |||
| 22 | Injector (Cylinder #2) (High) control output | Engine Running | PWM | |
| 23 | Injector (Cylinder #2) (Low) control output | Engine Running | Pulse | |
| 24 | - | |||
| 25 | Sensor ground | Idle | DC | -0.3 ~ 0.5V |
| 26 | - | |||
| 27 | Brake Switch 1 signal input | Brake OFF | DC | Max. 0.5V |
| Brake ON | Battery Voltage | |||
| 28 | - | |||
| 29 | Camshaft Position Sensor (CMPS) (Bank 1/Intake) signal input | Engine Running | Pulse | High: 4.5 ~ 5.5V |
| Low: -0.3 ~ 0.5V | ||||
| Frequency: 7Hz (Idle), 25Hz (3, 000 RPM) | ||||
| 30 | Camshaft Position Sensor (CMPS) (Bank 1/Exhaust) signal input | Engine Running | Pulse | High: 4.5 ~ 5.5V |
| Low: -0.3 ~ 0.5V | ||||
| Frequency: 7Hz (Idle), 25Hz (3, 000 RPM) | ||||
| 31 | - | |||
| 32 | LIN communication signal input | |||
| 33 | Cooling Fan Relay (Low) control output | Relay OFF | DC | Battery Voltage |
| Relay ON | -0.3 ~ 1.2V | |||
| 34 | - | |||
| 35 | - | |||
| 36 | - | |||
| 37 | - | |||
| 38 | - | |||
| 39 | Injector (Cylinder #3) (High) control output | Engine Running | PWM | |
| 40 | Injector (Cylinder #3) (Low) control output | Engine Running | Pulse | |
| 41 | Battery power (B+) | IG OFF | DC | Max. 1.0V |
| IG ON | Battery Voltage | |||
| 42 | - | |||
| 43 | - | |||
| 44 | Sensor shield | Idle | DC | -0.3 ~ 0.5V |
| 45 | Sensor ground | Idle | DC | -0.3 ~ 0.5V |
| 46 | Sensor ground | Idle | DC | -0.3 ~ 0.5V |
| 47 | Sensor ground | Idle | DC | -0.3 ~ 0.5V |
| 48 | - | |||
| 49 | - | |||
| 50 | - | |||
| 51 | - | |||
| 52 | - | |||
| 53 | Main Relay control output | Relay OFF | DC | Battery Voltage |
| Relay ON | -0.3 ~ 1.2V | |||
| 54 | - | |||
| 55 | - | |||
| 56 | Injector (Cylinder #4) (High) control output | Engine Running | PWM | |
| 57 | Injector (Cylinder #4) (Low) control output | Engine Running | Pulse | |
| 58 | Battery power (B+) | IG OFF | DC | Max. 1.0V |
| IG ON | Battery Voltage | |||
| 59 | - | |||
| 60 | CAN (Low) | Recessive | Pulse | 2.0 ~ 3.0V |
| Dominant | 2.75 ~ 4.5V | |||
| 61 | - | |||
| 62 | Knock Sensor (KS) signal input | Knocking | Variable Frequency | -0.3 ~ 0.3V |
| Normal | 0V | |||
| 63 | Clutch Switch signal input | S/W OFF | DC | Battery Voltage |
| S/W ON | -0.3 ~ 0.5V | |||
| 64 | - | |||
| 65 | - | |||
| 66 | - | |||
| 67 | - | |||
| 68 | - | |||
| 69 | Starter Relay control output | Relay OFF | DC | Battery Voltage |
| Relay ON | -0.3 ~ 1.2V | |||
| 70 | Fuel Pump Relay control output | Relay OFF | DC | Battery Voltage |
| Relay ON | -0.3 ~ 1.2V | |||
| 71 | Engine speed signal output | Engine Running | Frequency | High: Battery Voltage |
| Low: -0.3 ~ 1.0V | ||||
| Frequency: 26Hz (Idle), 106Hz (3, 000 RPM) | ||||
| 72 | RCV Control Solenoid Valve control output | |||
| 73 | Injector (Cylinder #1) (High) control output | Engine Running | PWM | |
| 74 | Injector (Cylinder #1) (Low) control output | Engine Running | Pulse | |
| 75 | Battery power (B+) | IG OFF | DC | Max. 1.0V |
| IG ON | Battery Voltage | |||
| 76 | - | |||
| 77 | CAN (High) | Recessive | Pulse | 2.0 ~ 3.0V |
| Dominant | 2.75 ~ 4.5V | |||
| 78 | Vehicle speed signal input | |||
| 79 | - | |||
| 80 | - | |||
| 81 | - | |||
| 82 | Starter Control Switch signal input | S/W OFF | DC | -0.3 ~ 0.5V |
| S/W ON | Battery Voltage | |||
| 83 | Fuel Level Sender (FLS) signal input | |||
| 84 | CVVT Oil Control Valve (OCV) (Bank 1/Exhaust) control output | Idle | Pulse | High: Battery Voltage |
| Low: -0.3 ~ 1.0V | ||||
| Frequency: 300Hz | ||||
| 85 | CVVT Oil Control Valve (OCV) (Bank 1/Intake) control output | Idle | Pulse | High: Battery Voltage |
| Low: -0.3 ~ 1.0V | ||||
| Frequency: 300Hz | ||||
| 86 | Purge Control Solenoid Valve (PCSV) control output | Inactive Active | Pulse | High: Battery Voltage |
| Low: Max. 1.0V | ||||
| Vpeak: 42.0 ~ 60.0V | ||||
| Frequency: 20Hz | ||||
| 87 | Canister Close Valve (CCV) control output | Active Inactive | Pulse | High: Battery Voltage |
| Low: Max. 1.0V | ||||
| Vpeak: 42.0 ~ 60.0V | ||||
| 88 | Heated Oxygen Sensor (HO2S) (Bank 1/Sensor 1) Heater control output | Engine Running | Pulse | High: Battery Voltage |
| Low: -0.3 ~ 1.0V | ||||
| Frequency: 8 ~ 10Hz | ||||
| Duty: 0 ~ 100% | ||||
| 89 | Heated Oxygen Sensor (HO2S) (Bank 1/Sensor 2) Heater control output | Engine Running | Pulse | High: Battery Voltage |
| Low: -0.3 ~ 1.0V | ||||
| Frequency: 8 ~ 10Hz | ||||
| Duty: 0 ~ 100% | ||||
| 90 | Fuel Pressure Regulator Valve (High) control output | Engine Running | PWM | |
| 91 | Fuel Pressure Regulator Valve (Low) control output | Engine Running | Pulse |
Factory Service Tools
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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.
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