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 MANUALSMERCURY1991TRACER BASE, 4D SEDAN, AUTOMATICREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 94 (ENGINE CONTROLS - TESTS W/CODES - EEC-IV)
1991 Mercury Tracer Base, 4D Sedan, Automatic
Section 94 (Engine Controls - Tests W/Codes - EEC-IV)
1991 Mercury Tracer Base, 4D Sedan, AutomaticSECTION Section 94 (Engine Controls - Tests W/Codes - EEC-IV)
WARNING: This page is about a different car, the 1995 Lincoln Mark VIII. However, it is still accessible from the selected car via links, so may be relevant.
- Introduction
- Self-Diagnostic System
- Quick Test
- Additional System Functions
- Summary
- Diagnostic Trouble Code Reference Charts
- Diagnostic Trouble Code Definition Charts
- Circuit Tests
- Notes
- How To Use Circuit Tests
- Circuit Test Ac - No-Start EI - DISTRIBUTORLESS Ignition Systems (High Data Rate)
- Circuit Test C - Reference Voltage
- Circuit Test DA - Temperature Sensor Test - IAT & ECT
- Circuit Test Db - EGR Temperature (EGRT) Sensor
- Circuit Test Dc - Mass Airflow (MAF) Sensor
- Circuit Test Dd - EGR Position (EGRP) Sensor, EGR Vacuum (EGRV) Solenoid & EGR Atmospheric (EGRA) Solenoid)
- Circuit Test DF - Map Absolute Pressure (Map)/Barometric Pressure (BARO) Sensor
- Circuit Test Dg - Knock Sensor (KS)
- Circuit Test DH - Throttle Position (TP) Sensor
- Circuit Test DL - Pressure Feedback EGR (PFE) Valve, Delta PFE (DPFE) Sensor & EGR Vacuum Regulator (EVR) Solenoid
- Circuit Test DN - EGR Valve Position (EVP) Sensor & EGR Valve Regulator (EVR) Solenoid
- Circuit Test DP - Vehicle Speed Sensor (VSS)
- Circuit Test Dr - Cylinder Identification (CID) Circuit
- Circuit Test DT - Power Steering Pressure (PSP) Sensor
- Circuit Test FD - Brake On-Off (Boo) Switch
- Circuit Test FE - Electrical Load Inputs
- Circuit Test Ff - Power Steering Pressure (PSP) Switch
- Circuit Test G - MAF/TP Fuel Injector Pulse Width Test
- Circuit Test H - Fuel Control
- Circuit Test Ha - Adaptive Fuel Strategy
- Circuit Test KD - Canister Purge (CANP)
- Circuit Test KE - Idle Air Control (IAC) Solenoid
- Circuit Test Kn - Fuel Pressure Regulator Control (FPRC) Solenoid
- Circuit Test KP - Octane Adjust
- Circuit Test Kt - Intake Manifold Runner Control (IMRC) System
- Circuit Test M - Dynamic Response Test
- Circuit Test Ml - Self-Test Output (STO) Or Malfunction Indicator Light (Mil)
- Circuit Test NC - Ignition Diagnostic Monitor (IDM) DISTRIBUTORLESS Ignition System (High Data Rate)
- Circuit Test Pc - Spark Timing Check - DISTRIBUTORLESS Ignition System (High Data Rate)
- Circuit Test QA - No Codes/Codes Not Listed
- Circuit Test QB - Diagnostic Trouble Code 512
- Circuit Test QC - Output State Check Not Functioning
- Circuit Test QD - Pcm Internal Voltage
- Circuit Test S - System Check
- Circuit Test Ta - Clutch Pedal Position (CPP) Switch/Park/Neutral Position (PNP) Switch
- Circuit Test Tb - Transmission Control Switch (TCS) & Transmission Control Indicator Light (TCIL)
- Circuit Test TC - Transmission Solenoids
- Circuit Test TD - Transmission Range (Tr) Sensor
- Circuit Test Te - Transmission Fluid Temperature (TFT) Sensor
- Circuit Test TG - Electronic Transmission Continuous Memory Diagnostic Trouble Codes
- Circuit Test XB - Variable Control Relay Module (VCRM)
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.