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.
THUNDERBIRD - 3.8L SPFI-Ma Service Code Definitions
1991 Mercury Cougar LS, 3.8 4SECTION THUNDERBIRD - 3.8L SPFI-Ma Service Code Definitions
3.8L SPFI-MA SC SERVICE CODE DEFINITIONS
| Service Code | Test Condition(s) | Definition |
|---|---|---|
| 111 | KOEO/KOER/ CONTINUOUS | System Pass. |
| 112 | KOEO/CONTINUOUS | Air Charge Temp (ACT) sensor circuit below minimum voltage/254° F indicated. |
| 113 | KOEO/CONTINUOUS | Air Charge Temp (ACT) sensor circuit above maximum voltage/-40° F indicated. |
| 114 | KOEO/KOER | Air Charge Temp (ACT) higher or lower than expected during KOEO, KOER. |
| 116 | KOEO/KOER | Engine Coolant Temp (ECT) higher or lower than expected during KOEO, KOER. |
| 117 | KOEO/CONTINUOUS | Engine Coolant Temp (ECT) sensor circuit below minimum voltage/ 254° F indicated. |
| 118 | KOEO/CONTINUOUS | Engine Coolant Temp (ECT) sensor circuit above maximum voltage/ -40° indicated. |
| 121 | KOEO/KOER/ CONTINUOUS | Closed throttle voltage higher or lower than expected. |
| 122 | KOEO/CONTINUOUS | Throttle Position (TP) Sensor circuit above maximum voltage. |
| 123 | KOEO/CONTINUOUS | Throttle Position (TP) Sensor voltage higher than expected. |
| 124 | CONTINUOUS | Throttle Position (TP) Sensor voltage higher than expected. |
| 125 | CONTINUOUS | Throttle Position (TP) Sensor voltage lower than expected. |
| 126 | KOEO/KOER/ CONTINUOUS | BP sensor higher or lower than expected. |
| 129 | KOER | Insufficient Mass Air Flow (MAF) change during Dynamic Response Test. |
| 136 | KOER | Lack of Oxygen Sensor (HEGO) switches, indicates lean (Left Side). |
| 137 | KOER | Lack of Oxygen Sensor (HEGO) switches, indicates rich (Left Side). |
| 139 | CONTINUOUS | No Oxygen Sensor (HEGO) switches detected (Left Side). |
| 144 | CONTINUOUS | No Oxygen Sensor (HEGO) switches detected (Right Side). |
| 157 | CONTINUOUS | Mass Air Flow (MAF) sensor circuit below minimum voltage. |
| 158 | KOEO/CONTINUOUS | Mass Air Flow (MAF) sensor circuit above maximum voltage. |
| 159 | KOEO/CONTINUOUS | Mass Air Flow (MAF) higher or lower than expected during KOEO, KOER. |
| 167 | KOER | Insufficient throttle position change during Dynamic Response Test. |
| 171 | CONTINUOUS | Fuel system at adaptive limits, Oxygen Sensor (HEGO) unable to switch (Left Side). |
| 172 | KOER/CONTINUOUS | Lack of Oxygen Sensor (HEGO) switches indicates lean (Right Side). |
| 173 | KOER/CONTINUOUS | Lack of Oxygen Sensor (HEGO) switches indicates rich (Right Side). |
| 175 | CONTINUOUS | Fuel system at adaptive limits, Oxygen Sensor (HEGO) unable to switch (Left Side). |
| 176 | CONTINUOUS | Lack of Oxygen Sensor (HEGO) switches, indicates lean (Left Side). |
| 177 | CONTINUOUS | Lack of Oxygen Sensor (HEGO) switches, indicates rich (Left Side). |
| 179 | CONTINUOUS | Fuel system at lean adaptive limit at part throttle, system rich (Right Side). |
| 181 | CONTINUOUS | Fuel system at rich adaptive limit at part throttle, system lean (Right Side). |
| 182 | CONTINUOUS | Fuel system at lean adaptive limit at idle, system rich (Right Side). |
| 183 | CONTINUOUS | Fuel system at rich adaptive limit at idle, system lean (Right Side). |
| 184 | CONTINUOUS | Mass Air Flow (MAF) higher than expected. |
| 185 | CONTINUOUS | Mass Air Flow (MAF) lower than expected. |
| 186 | CONTINUOUS | Injector pulse width higher than expected. |
| 187 | CONTINUOUS | Injector pulse width lower than expected. |
| 188 | CONTINUOUS | Fuel system at lean adaptive limit at part throttle, system rich, (Left Side). |
| 189 | CONTINUOUS | Fuel system at rich adaptive limit at part throttle, system lean, (Left Side). |
| 191 | CONTINUOUS | Fuel system at lean adaptive limit at idle, system rich, (Left Side). |
| 192 | CONTINUOUS | Fuel system at rich adaptive limit at idle, system lean, (Left Side). |
| 211 | CONTINUOUS | Profile Ignition Pickup (PIP) circuit fault. |
| 212 | CONTINUOUS | Loss of Ignition Diagnostic Monitor (IDM) input to EEC processor/SPOUT circuit grounded. |
| 213 | KOER | (SPOUT) circuit open. |
| 214 | CONTINUOUS | Cylinder Identification (CID) circuit failure. |
| 215 | CONTINUOUS | EEC processor detected coil 1 primary circuit failure. |
| 216 | CONTINUOUS | EEC processor detected coil 2 primary circuit failure. |
| 217 | CONTINUOUS | EEC processor detected coil 3 primary circuit failure. |
| 219 | CONTINUOUS | Spark timing defaulted to 10 degrees-SPOUT circuit open. |
| 341 | KOEO | Octane adjust service pin in use. |
| 411 | KOER | Cannot control RPM during KOER low RPM check. |
| 412 | KOER | Cannot control RPM during KOER high RPM check. |
| 452 | CONTINUOUS | Insufficient input from the Vehicle Speed Sensor (VSS). |
| 511 | KOEO | EEC Processor Read Only Memory (ROM) test failure. |
| 512 | CONTINUOUS | EEC Processor Keep Alive Memory (KAM) test failure. |
| 522 | KOEO | Vehicle not in Park or Neutral during KOEO. |
| 525 | KOEO | Indicates vehicle in gear/ AC On. |
| 528 | CONTINUOUS | Clutch switch circuit failure. |
| 536 | KOEO | Brake On/Off (BOO) circuit failure/not actuated during KOER. |
| 538 | KOER | Insufficient RPM change during KOER Dynamic Response Test. |
| 539 | KOER | AC On/Defrost On during KOEO. |
| 542 | KOEO/CONTINUOUS | Fuel pump secondary circuit failure. |
| 543 | KOEO/CONTINUOUS | Fuel pump secondary circuit failure. |
| 556 | KOEO/CONTINUOUS | Fuel pump relay primary circuit failure. |
| 558 | KOEO | EGR Vacuum Regulator (EVR) circuit failure. |
| 563 | KOEO | High Speed Electro Drive Fan (HEDF) circuit failure. |
| 564 | KOEO | Electro Drive Fan (EDF) circuit failure. |
| 565 | KOEO | Canister purge (CANP) circuit failure. |
| 998 | KOER | Hard fault present ****FMEM mode****. |
RENDER: 1.0x
NO RELATED
Recommended Tools & Savings
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
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.