Diagnosis and Testing - Catalyst System

Diagnostic Trouble Code (DTC) Chart

The diagnosis in this manual assumes a certain level of skill and knowledge of Ford-approved diagnostic procedures.
REFER TO: Diagnostic Methods (100-00 General Information, Description and Operation).

Global Customer Symptom Codes (GCSC) Table

The diagnosis in this manual assumes a certain level of skill and knowledge of Ford-approved diagnostic procedures.
REFER TO: Diagnostic Methods (100-00 General Information, Description and Operation).

Pinpoint Tests

PINPOINT TEST EM: EMISSIONS COMPLIANCE

• Engine or catalyst temperature has not warmed up and stabilized before testing.
• Excessive vehicle idling before testing.

Normal Operation and Fault Symptoms

If any new emission components have been installed, complete the following steps before repeating the inspection/maintenance (I/M) test procedure:

• Reset the KAM. Refer to Keep Alive Memory (KAM) Reset.
• To relearn some of the baseline adaptive learning values (trims), run the engine at 2500 rpm for 1 minute and at idle for 2 minutes.

Check the reading for excessive grams per mile (gallons per minute) using parts per million (ppm) readings.

For excessive vehicle emission readings, compare the actual reading in gallons per minute to the emission level required to pass the test. This gives an indication of how much the ppm reading must be reduced. (If the actual reading is twice the threshold value, the baseline reading must be cut in half or more.)

Example:

• The actual amount of hydrocarbons produced by the vehicle is 1.6 gallons per minute. The threshold value for HC in this example is 0.8 gallons per minute. The actual value is twice the threshold value.
• The HC reading obtained for the same vehicle during the baseline average driving was 440 ppm. For this vehicle to pass the inspection/maintenance (I/M) test, the HC readings from the verification drive must be at least half of the baseline reading, or an average of 220 ppm or less.
• This method provides only a general indication of how much the ppm readings must be significantly reduced for the vehicle to pass the inspection/maintenance (I/M) test, which calculates gallons per minute. This test is not exact. Experience is still required to determine whether the emission readings are reduced enough for the vehicle to pass the inspection/maintenance (I/M) test.

Possible Sources

• Air Intake System Concern
• Exhaust System Concern
• Fuel System Concern
• Ignition System Concern

PINPOINT TEST HF: CATALYST EFFICIENCY AND EXHAUST SYSTEM MONITOR

Introduction Normal Operation and Fault Symptoms Refer to DTC Fault Trigger Conditions. DTC Fault Trigger Conditions Trouble Code Description Fault Trigger Condition DTC P0420:00 Catalyst System Efficiency Below Threshold (Bank 1): No subtype information Set when the PCM detects that the catalyst system efficiency for Bank 1 is below the acceptable threshold. Under normal closed-loop fuel conditions, high-efficiency catalysts contain oxygen storage capacity. As catalyst efficiency decreases, its oxygen storage capacity decreases. See the Catalyst Efficiency Monitor description for additional information. Diagnose any underlying engine concerns. Refer to the appropriate Section 303-00, Engine System. DTC P0430:00 Catalyst System Efficiency Below Threshold (Bank 2): No subtype information Set when the PCM detects that the catalyst system efficiency for Bank 2 is below the acceptable threshold. Under normal closed-loop fuel conditions, high-efficiency catalysts contain oxygen storage capacity. As catalyst efficiency decreases, its oxygen storage capacity decreases. See the Catalyst Efficiency Monitor description for additional information. Diagnose any underlying engine concerns. Refer to the appropriate Section 303-00, Engine System. Possible Sources Oxygen Sensor 2WD Circuit Diagram 4WD Exhaust System Concern Contaminated Oil Base Engine Fuel Injector Turbocharger Oxygen Sensor