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.
1997 Lincoln Mark VIII BaseFACTORY OEM SERVICE PROCEDURE
Diagnostic Trouble Code (DTC) Reference Charts
DTC REFERENCE CHART
| DTC | Description | Circuit Test/Step: KOEO | Circuit Test/Step: KOER | Circuit Test/Step: CONT. | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| P0102 | Mass Air Flow Circuit Low Input | - | DC/6 | DC/6 | ||||||
| P0103 | Mass Air Flow Circuit High Input | DC/20 | DC/20 | DC/20 | ||||||
| P0112 | Intake Air Temperature Circuit Low Input | DA/20 | DA/20 | DA/90 | ||||||
| P0113 | Intake Air Temperature Circuit High Input | DA/10 | DA/10 | DA/90 | ||||||
| P0117 | Engine Coolant Temperature Circuit Low Input | DA/20 | DA/20 | DA/90 | ||||||
| P0118 | Engine Coolant Temperature Circuit High Input | DA/10 | DA/10 | DA/90 | ||||||
| P0121 | Throttle Position Circuit Performance Problem | - | DH/22 | DH/22 | ||||||
| P0122 | Throttle Position Circuit Low Input | DH/11 | DH/11 | DH/11 | ||||||
| P0123 | Throttle Position Circuit High Input | DH/8 | DH/8 | DH/8 | ||||||
| P0125 | Insufficient Coolant Temperature For Closed Loop Fuel Control | - | - | DA/100 | ||||||
| P0131 | Heated Oxygen Sensor (HO2S-11) Circuit Out Of Range Low Voltage | - | - | H/27 | ||||||
| P0133 | Heated Oxygen Sensor (HO2S-11) Circuit Slow Response | - | - | H/20 | ||||||
| P0135 | Heated Oxygen Sensor (HO2S-11) Circuit Malfunction | H/30 | H/30 | H/30 | ||||||
| P0136 | Heated Oxygen Sensor (HO2S-12) Circuit Malfunction | - | - | H/80 | ||||||
| P0141 | Heated Oxygen Sensor (HO2S-12) Circuit Malfunction | H/30 | H/30 | H/30 | ||||||
| P0151 | Heated Oxygen Sensor (HO2S-21) Circuit Out Of Range Low Voltage | - | - | H/27 | ||||||
| P0153 | Heated Oxygen Sensor (HO2S-21) Circuit Slow Response | - | - | H/20 | ||||||
| P0155 | Heated Oxygen Sensor (HO2S-11) Circuit Malfunction | H/30 | H/30 | H/30 | ||||||
| P0156 | Heated Oxygen Sensor (HO2S-22) Circuit Malfunction | - | - | H/80 | ||||||
| P0161 | Heated Oxygen Sensor (HO2S-22) Circuit Malfunction | H/30 | H/30 | H/30 | ||||||
| P0171 | System To Lean (Bank 1) | - | - | H/41 | ||||||
| P0172 | System To Rich (Bank 1) | - | - | H/41 | ||||||
| P0174 | System To Lean (Bank 2) | - | - | H/41 | ||||||
| P0175 | System To Rich (Bank 2) | - | - | H/41 | ||||||
| P0222 | Throttle Position Sensor B Low Input | HT/1 | HT/1 | HT/1 | ||||||
| P0223 | Throttle Position Sensor B High Input | HT/10 | HT/10 | HT/10 | ||||||
| P0230 | Fuel Pump Primary Circuit Malfunction | KB/30 | KB/30 | KB/30 | ||||||
| P0231 | Fuel Pump Secondary Circuit Low Input | KA/20 | KA/20 | KA/35 | ||||||
| P0232 | Fuel Pump Secondary Circuit High Input | KA/10 | KA/10 | KA/30 | ||||||
| P0300 | Random Misfire | - | HD/1 | HD/1 | ||||||
| P0301 | Misfire Detection Monitor - Cylinder No. 1 | - | HD/1 | HD/1 | ||||||
| P0302 | Misfire Detection Monitor - Cylinder No. 2 | - | HD/1 | HD/1 | ||||||
| P0303 | Misfire Detection Monitor - Cylinder No. 3 | - | HD/1 | HD/1 | ||||||
| P0304 | Misfire Detection Monitor - Cylinder No. 4 | - | HD/1 | HD/1 | ||||||
| P0305 | Misfire Detection Monitor - Cylinder No. 5 | - | HD/1 | HD/1 | ||||||
| P0306 | Misfire Detection Monitor - Cylinder No. 6 | - | HD/1 | HD/1 | ||||||
| P0307 | Misfire Detection Monitor - Cylinder No. 7 | - | HD/1 | HD/1 | ||||||
| P0308 | Misfire Detection Monitor - Cylinder No. 8 | - | HD/1 | HD/1 | ||||||
| P0320 | Ignition Engine Speed Input Circuit Malfunction | - | - | NC/1 | ||||||
| P0325 | Knock Sensor 1 Circuit Malfunction (Bank 1) | - | DG/1 | DG/1 | ||||||
| P0326 | Knock Sensor 1 Circuit Range/Performance (Bank 1) | - | DG/1 | DG/1 | ||||||
| P0330 | Knock Sensor 2 Circuit Malfunction (Bank 2) | - | DG/1 | DG/1 | ||||||
| P0331 | Knock Sensor 2 Circuit Range/Performance (Bank 2) | - | DG/1 | DG/1 | ||||||
| P0340 | Camshaft Position Sensor Circuit Malfunction | - | DR/1 | DR/1 | ||||||
| P0350 | Ignition Coil Primary/Secondary Circuit Malfunction | - | - | JF/1 | ||||||
| P0351 | Ignition Coil A Primary/Secondary Circuit Malfunction | - | - | JF/1 | ||||||
| P0352 | Ignition Coil B Primary/Secondary Circuit Malfunction | - | - | JF/1 | ||||||
| P0353 | Ignition Coil C Primary/Secondary Circuit Malfunction | - | - | JF/1 | ||||||
| P0354 | Ignition Coil D Primary/Secondary Circuit Malfunction | - | - | JF/1 | ||||||
| P0355 | Ignition Coil E Primary/Secondary Circuit Malfunction | - | - | JF/1 | ||||||
| P0356 | Ignition Coil F Primary/Secondary Circuit Malfunction | - | - | JF/1 | ||||||
| P0357 | Ignition Coil G Primary/Secondary Circuit Malfunction | - | - | JF/1 | ||||||
| P0358 | Ignition Coil H Primary/Secondary Circuit Malfunction | - | - | JF/1 | ||||||
| P0401 | Exhaust Gas Recirculation Flow Insufficient | - | - | HE/70 | ||||||
| P0402 | Exhaust Gas Recirculation Flow Excessive | - | HE/20 | HE/20 | ||||||
| P0411 | Secondary Air Injection System - Electric Air Pump | HM/7 | HM/7 | HM/7 | ||||||
| P0412 | Secondary Air Injection System Circuit Malfunction | HM/1 | HM/1 | HM/1 | ||||||
| P0413 | Secondary Air Injection System | HM/75 | HM/75 | HM/75 | ||||||
| P0414 | Secondary Air Injection System | HM/75 | HM/75 | HM/75 | ||||||
| P0416 | Secondary Air Injection System | HM/75 | HM/75 | HM/75 | ||||||
| P0417 | Secondary Air Injection System | HM/75 | HM/75 | HM/75 | ||||||
| P0420 | Catalyst System Efficiency Below Threshold (Bank 1) | - | - | HF/1 | ||||||
| P0430 | Catalyst System Efficiency Below Threshold (Bank 2) | - | - | HF/1 | ||||||
| P0442 | Evaporative Emission Control System Leak (Small Leak) | - | - | HX/1 | ||||||
| P0443 | Evaporative Emission Control System Canister Purge Valve Circuit Malfunction | HX/7 | HX/7 | HX/6 | ||||||
| P0446 | Evaporative Emission Control System Excessive Fuel Tank Vacuum | - | - | HX/13 | ||||||
| P0452 | Fuel Tank Pressure Sensor Circuit Low Voltage | HX/22 | HX/22 | HX/22 | ||||||
| P0453 | Fuel Tank Pressure Sensor Circuit High Voltage | HX/28 | HX/28 | HX/28 | ||||||
| P0455 | Evaporative Emission Control System Leak (No Purge Flow Or Large Leak) | - | - | HX/39 | ||||||
| P0500 | Vehicle Speed Sensor Malfunction | - | - | DP/1 | ||||||
| P0501 | Vehicle Speed Sensor Range/Performance | - | - | DP/1 | ||||||
| P0503 | Vehicle Speed Sensor Intermittent | - | - | DP/20 | ||||||
| P0505 | Vehicle Speed Sensor Intermittent | - | KE/2 | - | ||||||
| P0603 | Powertrain Control Module KAM Test Error | QB/1 | - | - | ||||||
| P0605 | Powertrain Control Module Read Only Memory Error | Replace PCM | Replace PCM | Replace PCM | ||||||
| P0703 | Brake Switch Circuit Input Malfunction | - | - | FD/3 | ||||||
| P0705 | Digital Transmission Range Circuit Failure | (1) | - | - | ||||||
| P0707 | Transmission Range Circuit Low Voltage | - | - | (1) | ||||||
| P0708 | Transmission Range Circuit High Voltage | - | - | (1) | ||||||
| P0712 | Transmission Fluid Temperature Sensor Circuit Grounded | (1) | (1) | (1) | ||||||
| P0713 | Transmission Fluid Temperature Sensor Circuit Open | (1) | (1) | (1) | ||||||
| P0720 | Insufficient Input From Output Shaft Speed Sensor | - | - | (1) | ||||||
| P0721 | Noise Interference On Output Shaft Speed Sensor Signal | - | - | (1) | ||||||
| P0741 | Torque Converter Clutch Engagement Error | - | - | (1) | ||||||
| P0743 | Torque Converter Clutch Solenoid Circuit Failure | (1) | (1) | (1) | ||||||
| P0750 | Shift Solenoid 1 Circuit Failure | (1) | (1) | (1) | ||||||
| P0751 | Shift Solenoid 1 Functional Failure | - | - | (1) | ||||||
| P0755 | Shift Solenoid 2 Circuit Failure | (1) | (1) | (1) | ||||||
| P0756 | Shift Solenoid 2 Functional Failure | - | - | (1) | ||||||
| P0781 | 1-2 Shift Error | - | - | (1) | ||||||
| P0782 | 2-3 Shift Error | - | - | (1) | ||||||
| P0783 | 3-4 Shift Error | - | - | (1) | ||||||
| P1000 | Monitor Testing Not Complete | (2) | (2) | QC/1 | ||||||
| P1001 | KOER Not Able To Complete, KOER Aborted | - | QA/1 | - | ||||||
| P1100 | Mass Air Flow Sensor Intermittent | - | - | DC/3 | ||||||
| P1101 | Mass Air Flow Sensor Out Of Self-Test Range | DC/2 | DC/1 | - | ||||||
| P1112 | Intake Air Temperature Sensor Intermittent | - | - | DA/90 | ||||||
| P1116 | Engine Coolant Temperature Sensor Out Of Self-Test Range | DA/1 | DA/1 | - | ||||||
| P1117 | Engine Coolant Temperature Sensor Intermittent | - | - | DA/90 | ||||||
| P1120 | Throttle Position Sensor Out Of Range Low (RATCH Too Low) | DH/3 | DH/3 | DH/3 | ||||||
| P1121 | Throttle Position Sensor Inconsistent With MAF Sensor | - | - | DH/15 | ||||||
| P1124 | Throttle Position Sensor Out Of Self-Test Range | DH/1 | DH/1 | - | ||||||
| P1125 | Throttle Position Sensor Intermittent | - | - | DH/20 | ||||||
| P1127 | Exhaust Not Warm Enough, Downstream Sensor Not Tested | - | H/100 | - | ||||||
| P1128 | Upstream Oxygen Sensors Swapped From Bank To Bank (HO2S-11-21) | - | H/110 | - | ||||||
| P1129 | Downstream Oxygen Sensors Swapped From Bank To Bank (HO2S-12-22) | - | H/110 | - | ||||||
| P1130 | Lack Of HO2S-11 Switch, Fuel Trim At Limit | - | - | H/40 | ||||||
| P1131 | Lack Of HO2S-11 Switch, Sensor Indicates Lean | - | H/40 | H/40 | ||||||
| P1132 | Lack Of HO2S-11 Switch, Sensor Indicates Rich | - | H/40 | H/40 | ||||||
| P1137 | Lack Of HO2S-12 Switch, Sensor Indicates Lean | - | H/80 | - | ||||||
| P1138 | Lack Of HO2S-12 Switch, Sensor Indicates Rich | - | H/80 | - | ||||||
| P1150 | Lack Of HO2S-21 Switch, Fuel Trim At Limit | - | - | H/40 | ||||||
| P1151 | Lack Of HO2S-21 Switch, Sensor Indicates Lean | H/40 | H/40 | H/40 | ||||||
| P1152 | Lack Of HO2S-21 Switch, Sensor Indicates Rich | - | H/40 | H/40 | ||||||
| P1157 | Lack Of HO2S-22 Switch, Sensor Indicates Lean | - | H/80 | - | ||||||
| P1158 | Lack Of HO2S-22 Switch, Sensor Indicates Rich | - | H/80 | - | ||||||
| P1220 | Series Throttle Control System Malfunction | HT/20 | HT/20 | HT/20 | ||||||
| P1224 | Throttle Position Sensor B Voltage Out Of Range | HT/40 | HT/40 | HT/40 | ||||||
| P1233 | Fuel System Disabled Or Offline | KB/1 | KB/1 | KB/1 | ||||||
| P1234 | Fuel System Disabled Or Offline | KB/1 | KB/1 | KB/1 | ||||||
| P1235 | Fuel Pump Control Out Of Range | KB/30 | KB/30 | KB/30 | ||||||
| P1236 | Fuel Pump Control Out Of Range | KB/30 | KB/30 | KB/30 | ||||||
| P1237 | Fuel Pump Secondary Circuit Malfunction | KB/47 | KB/47 | KB/47 | ||||||
| P1238 | Fuel Pump Secondary Circuit Malfunction | KB/47 | KB/47 | KB/47 | ||||||
| P1260 | Theft Detected - Vehicle Immobilized | - | - | QD/1 | ||||||
| P1270 | Engine RPM/Vehicle Speed Limiter | - | - | ND/1 | ||||||
| P1285 | Cylinder Head Over Temperature Sensed | - | - | DL/30 | ||||||
| P1288 | Cylinder Head Temperature Sensor Circuit Out Of Self-Test Range | DL/1 | DL/1 | - | ||||||
| P1289 | Cylinder Head Temperature Sensor Circuit High Input | DL/10 | DL/10 | DL/90 | ||||||
| P1290 | Cylinder Head Temperature Sensor Circuit Low Input | DL/20 | DL/20 | DL/90 | ||||||
| P1299 | Cylinder Head Over Temperature Protection Active | - | - | DL/100 | ||||||
| P1309 | Misfire Monitor Disabled | - | - | HD/40 | ||||||
| P1390 | Octane Adjust | FG/1 | - | - | ||||||
| P1400 | Differential Pressure Feedback Exhaust Gas Recirculation Sensor Circuit Low Voltage | HE/1 | HE/1 | HE/1 | ||||||
| P1401 | Differential Pressure Feedback Exhaust Gas Recirculation Sensor Circuit High Voltage | HE/10 | HE/10 | HE/10 | ||||||
| P1405 | Differential Pressure Feedback Exhaust Gas Recirculation Sensor Upstream Hose Off Or Plugged | - | - | HE/50 | ||||||
| P1406 | Differential Pressure Feedback Exhaust Gas Recirculation Sensor Downstream Hose Off Or Plugged | - | - | HE/60 | ||||||
| P1408 | Exhaust Gas Recirculation Flow Out Of Self-Test Range | - | HE/71 | - | ||||||
| P1409 | Exhaust Gas Recirculation Vacuum Regulator Solenoid Circuit Malfunction | HE/110 | HE/110 | HE/120 | ||||||
| P1411 | Secondary Air Injection System Downstream Flow | HM/40 | HM/40 | HM/40 | ||||||
| P1413 | Secondary Air Injection System Monitor Circuit Low | HM/18 | HM/18 | HM/18 | ||||||
| P1414 | Secondary Air Injection System Monitor Circuit High | HM/25 | HM/25 | HM/25 | ||||||
| P1442 | Evaporative Emission Control System Leak Detected (Small Leak) | - | - | HX/1 | ||||||
| P1443 | Very Small Or No Purge Flow Condition | - | - | HW/6 | ||||||
| P1444 | Purge Flow Sensor Circuit Low Input | - | - | HW/27 | ||||||
| P1445 | Purge Flow Sensor Circuit High Input | - | - | HW/33 | ||||||
| P1450 | Evaporative Emission Control System Excessive Fuel Tank Vacuum | - | - | HX/56 | ||||||
| P1451 | Evaporative Emission Control System Canister Vent Solenoid Circuit Malfunction | HX/65 | HX/65 | HX/65 | ||||||
| P1452 | Evaporative Emission Control System Unable To Bleed Up Fuel Tank Vacuum | - | - | HX/56 | ||||||
| P1455 | Evaporative Emission Control System Detected Large Leak Or No Purge Flow | - | - | HX/40 | ||||||
| P1460 | Wide Open Throttle A/C Cutout Primary Circuit Malfunction | KM/1 | KM/1 | KM/30 | ||||||
| P1461 | Air Conditioning Pressure Sensor High Voltage | KM/1 | KM/1 | KM/30 | ||||||
| P1462 | Air Conditioning Pressure Sensor Low Voltage | KM/1 | KM/1 | KM/30 | ||||||
| P1463 | Air Conditioning Pressure Sensor Insufficient Pressure Change | KM/1 | KM/1 | KM/30 | ||||||
| P1464 | A/C Demand Out Of Self-Test Range | XB/75 | XB/75 | - | ||||||
| P1483 | Power-To-Cooling Fan Circuit Exceeded Normal Current Draw | XB/10 | XB/10 | XB/10 | ||||||
| P1484 | Variable Load Control Module PWR GND Open | XB/1 | XB/1 | XB/1 | ||||||
| P1500 | Vehicle Speed Sensor Intermittent | - | - | DP/25 | ||||||
| P1501 | Vehicle Speed Sensor Out Of Self Test Range | - | DP/15 | - | ||||||
| P1504 | Idle Air Control Circuit Malfunction | KE/2 | KE/2 | KE/2 | ||||||
| P1505 | Idle Air Control System Reached Idle Air Trim Limit | KE/25 | KE/25 | KE/25 | ||||||
| P1506 | Idle Air Control Overspeed Error | - | KE/20 | KE/20 | ||||||
| P1507 | Idle Air Control Underspeed Error | - | KE/2 | KE/2 | ||||||
| P1512 | Intake Manifold Runner Control Malfunction (Stuck Closed) | - | - | HU/15 | ||||||
| P1513 | Intake Manifold Runner Control Malfunction (Stuck Closed) | - | - | HU/15 | ||||||
| P1516 | Intake Manifold Runner Control Input Error | HU/15 | - | HU/15 | ||||||
| P1517 | Intake Manifold Runner Control Input Error | HU/15 | - | HU/15 | ||||||
| P1518 | Intake Manifold Runner Control Malfunction (Stuck Open) | HU/15 | HU/15 | HU/15 | ||||||
| P1519 | Intake Manifold Runner Control Malfunction (Stuck Closed) | HU/15 | HU/15 | HU/15 | ||||||
| P1520 | Intake Manifold Runner Control Circuit Malfunction | HU/15 | HU/15 | HU/15 | ||||||
| P1530 | Open Or Short To Power In Power-To-A/C Clutch Circuit | XB/50 | XB/50 | XB/50 | ||||||
| P1537 | Intake Manifold Runner Control Malfunction (Stuck Open) | HU/15 | HU/15 | HU/15 | ||||||
| P1538 | Intake Manifold Runner Control Malfunction (Stuck Open) | HU/15 | HU/15 | HU/15 | ||||||
| P1539 | Power-To-A/C Clutch Circuit Exceeded Normal Current Draw | XB/40 | XB/40 | XB/40 | ||||||
| P1549 | Intake Manifold Communication Control Circuit Malfunction | HU/65 | HU/65 | HU/65 | ||||||
| P1605 | Keep Alive Memory Test Failure | QB/1 | - | - | ||||||
| P1625 | Variable Load Control Module Fan Circuit B+ Supply Not Detected | XB/60 | XB/60 | XB/65 | ||||||
| P1626 | Variable Load Control Module A/C Circuit B+ Supply Not Detected | XB/60 | XB/60 | XB/65 | ||||||
| P1703 | Brake ON/OFF Circuit Failure | FD/2 | FD/1 | - | ||||||
| P1705 | Digital Transmission Range Not Indicating PARK | (1) | (1) | - | ||||||
| P1710 | Transmission Fluid Temperature Sensor In Range Malfunction | (1) | (1) | - | ||||||
| P1711 | Transmission Fluid Temperature Out Of Self-Test Range | (1) | (1) | - | ||||||
| P1714 | Shift Solenoid 1 Malfunction | - | - | (1) | ||||||
| P1715 | Shift Solenoid 2 Malfunction | - | - | (1) | ||||||
| P1728 | Transmission Slippage Error | - | - | (1) | ||||||
| P1740 | Torque Converter Clutch Malfunction | - | - | (1) | ||||||
| P1741 | Excessive Torque Converter Clutch Slippage | - | - | (1) | ||||||
| P1742 | Torque Converter Clutch Solenoid Failed ON | - | - | (1) | ||||||
| P1743 | Torque Converter Clutch Solenoid Failed ON | - | - | (1) | ||||||
| P1744 | Excessive Torque Converter Clutch Slippage During Full Engagement | - | - | (1) | ||||||
| P1746 | Open Powertrain Control Module Output Driver | (1) | - | (1) | ||||||
| P1747 | Electronic Pressure Control Solenoid Circuit Failure | (1) | - | (1) | ||||||
| P1751 | Shift Solenoid 1 Functional Failure | - | - | (1) | ||||||
| P1756 | Shift Solenoid 2 Functional Failure | - | - | (1) | ||||||
| P1767 | Torque Converter Clutch Solenoid Circuit Failure | (1) | - | (1) | ||||||
| P1780 | Transmission Control Switch Out Of Self-Test Range | - | TB/1 | - | ||||||
| P1783 | Transmission Fluid Temperature Exceeded | - | - | (1) | ||||||
| U1009 | SCP Invalid Or Missing Data For Engine Torque | - | - | (3) | ||||||
| U1027 | SCP Invalid Or Missing Data For Engine RPM | - | - | (3) | ||||||
| U1059 | SCP Invalid or Missing Data for Transmission/Transaxle/PRNDL | - | - | (3) | ||||||
| U1073 | SCP Invalid or Missing Data for Engine Coolant | - | - | (3) | ||||||
| U1135 | SCP Invalid or Missing Data for Ignition Switch/Starter | - | - | (3) | ||||||
| U1136 | SCP Invalid Or Missing Data For Telltales | - | - | (3) | ||||||
| U1430 | SCP Invalid or Missing Data for Function Read Fuel System | - | - | (3) | ||||||
| Uxxxx | Module Communication Network Failure | (3) | (3) | (3) | ||||||
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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.