Diagnostic Trouble Code (DTC) Ref Chart (Codes P0306-P1138)

1991 Mercury Tracer Base, 4D Sedan, AutomaticSECTION Diagnostic Trouble Code (DTC) Ref Chart (Codes P0306-P1138)
WARNING: This page is about a different car, the 1994 Mercury Cougar and 1994 Ford Thunderbird. However, it is still accessible from the selected car via links, so may be relevant.
DTC REFERENCE

3-Digit Code Description Go To KOEO Go To KOER Go To CONT.
P0306  Misfire Monitor -- HD1 HD1
P0307  Misfire Monitor -- HD1 HD1
P0308  Misfire Monitor -- HD1 HD1
P0320  Ignition Diagnostic Monitor (IDM) -- -- NA1
P0340  Cylinder Identification (CID) Circuit -- -- DR1
P0402  EGR System -- HE20 HE20
P0420  Catalyst Efficiency Monitor & Exhaust Systems -- -- HF20
P0430  Catalyst Efficiency Monitor & Exhaust Systems -- -- HF20
P0443  Evaporative Emission System HV9 HV9 HV9
P0500  Vehicle Speed Sensor (VSS) -- -- DP1
P0505  Idle Air Control (IAC) Valve -- KE2 --
P0703  Brake On-Off (BOO) Switch -- FD1 FD1
P0705  Elect Transmission Continuous Memory DTC -- -- TG90
P0707  Elect Transmission Continuous Memory DTC -- -- TG90
P0708  Elect Transmission Continuous Memory DTC -- -- TG90
P0712 Transmission Fault TE  1 TE  1 TG  90
P0713  Transmission Fluid Temperature (TFT) Sensor TE10 TE10 TE100
P0720  Output Shaft Speed (OSS) Sensor -- -- TF1
P0731  Elect Transmission Continuous Memory DTC -- -- TG90
P0732  Elect Transmission Continuous Memory DTC -- -- TG90
P0733  Elect Transmission Continuous Memory DTC -- -- TG90
P0734  Elect Transmission Continuous Memory DTC -- -- TG90
P0735  Elect Transmission Continuous Memory DTC -- -- TG90
P0741  Elect Transmission Continuous Memory DTC -- -- TG90
P0743 Transmission Fault TC  1 -- TG  90
P0750 Transmission Fault TC  1 -- TG  90
P0755 Transmission Fault TC  1 -- TG  90
P0756 Transmission Fault TC  1 -- TG  90
P1000  Diagnostic Trouble Code P1000 (1) (1) QC1
P1100  Mass Airflow (MAF) Sensor -- -- DC2
P1101  Mass Airflow (MAF) Sensor DC1 DC1 --
P1112  Temperature Sensor Test (IAT & ECT) -- -- DA90
P1116  Temperature Sensor Test (IAT & ECT) DA1 DA1 --
P1117  Temperature Sensor Test (IAT & ECT) -- -- DA90
P1120  Throttle Position (TP) Sensor DH2 DH2 DH2
P1121  Throttle Position (TP) Sensor -- -- DH12
P1124  Throttle Position (TP) Sensor DH1 DH1 --
P1125  Throttle Position (TP) Sensor -- -- DH17
P1130  Fuel Control -- -- H40
P1131  Fuel Control -- H40 H40
P1132  Fuel Control -- H40 H40
P1137  Fuel Control -- H80 --
P1138  Fuel Control -- H80 --
(1) DTC P1000 is disregarded in KOEO & KOER self test.
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.