DTC P0133 [YF (2.0L Zetec)]

DTC P0133	HO2S (Front) circuit slow response
DETECTION CONDITION	• The PCM monitors the input voltage frequency and amplitude from the HO2S-11. If during testing the frequency and amplitude were to fall below a calibrated limit, the PCM determines the HO2S-11 sensor circuit slow response.
POSSIBLE CAUSE	• Contaminated HO2S-11 • Exhaust leaks • Short or open circuit • Improper fueling • Damaged MAF sensor • Deteriorating HO2S-11 • Inlet air leaks


STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA HAS BEEN RECORDED • Has FREEZE FRAME DATA been recorded?	Yes	Go to next step.
1		No	Record the FREEZE FRAME DATA on the repair order, then go to the next step.
2	VERIFY REPAIR INFORMATION AVAILABILITY • Verify related service repair information availability. • Is any related repair information available?	Yes	Perform repair or diagnosis according to the available repair information. If the vehicle is not repaired, go to the next step.
2		No	Go to next step.
3	INDETIFY TRIGGER DTC FOR FREEZE FRAME DATA • Is DTC P0133 on FREEZE FRAME DATA?	Yes	Go to next step.
3		No	Go to FREEZE FRAME DATA DTC inspection. (See DTC TABLE [YF (2.0L Zetec)].)
4	HO2S-11 RESPONSE TEST • Connect the WDS or equivalent to DLC-2. • Turn the ignition switch to ON • Select Generic OBD Function from the menu and trigger. • Press continue. • Select Diagnostic Monitoring Test Results from menu and press trigger. • Scroll to Test ID: 01 and press trigger. • Turn the ignition switch to OFF. • Is the indicated value greater than minimum threshold?.	Yes	Intermittent malfunction exist, go to Step 11.
4		No	Go to the next step.
5	CHECK FOR UNMETERED AIR LEAKS Note • Fuel calculations can be affected by unmetered air leaks. • Carefully inspect the following areas for potential air leaks. - Hoses connecting to MAF sensor assembly - Hoses connecting to throttle body - Intake manifold gaskets leaks - PCV disconnected - Vacuum lines disconnected - Improperly seated engine oil dipstick, tube, and oil fill cap - Exhaust leaks at flanges and gaskets • Are there any air leaks present?	Yes	Repair or replace for malfunctioning part, then go to Step 11.
5		No	Go to the next step.
6	CHECK HO2S-11 CIRCUIT WIRING Note • Refer to the PCM connector pin number in the beginning of this pinpoint test. • Disconnect HO2S-11 connector • Check for water for contamination • Jumper HO2S-11 signal to VPWR at the HO2S-11 harness connector. • Connect the WDS or equivalent to the DLC-2. • Turn the ignition switch to ON. • Access O2S11 PID. • Does the O2S-11 PID indicate greater than 1.50 V?	Yes	Replace HO2S-11 and oil filter. Then go to Step 11.
6		No	Go to the next step.
7	CHECK HO2S SIGNAL AND SIGNAL RETURN CIRCUITS FOR OPEN IN HARNESS • Measure resistance for following HO2S-11 harnesses at harness side connectors: - Between HO2S-11 terminal 4 and PCM terminal 60 - Between HO2S-11 terminal 3 and PCM terminal 91 • Is the resistance less than 5.0 ohms?	Yes	Go to the next step.
7		No	Repair open circuit, then go to Step 11.
8	CHECK HO2S-11 CIRCUIT FOR SHORT TO VPWR IN HARNESS • Measure resistance between PCM terminal 60 and 71, 97 at PCM harness connector pin. • Is the resistance greater than 10,000 ohms?	Yes	Go to the next step.
8		No	Go to Step 10.
9	CHECK FOR SOURCE OF POTENTIAL HO2S-11 CONTAMINATION • Investigate the following items as potential sources of HO2S-11 contamination. - Use of unapproved silicon sealers. - Fuel contaminated by silicon additives. - Excessive oil burning. (i.e.: rings, valve seals and oil overfill) - Glycol (antifreeze) leaking internally in the engine. - Lead contaminated fuel - Short drive cycles in cold weather - Use of unapproved cleaning agents • Where any of the above conditions or concerns found during inspection?	Yes	Repair for source of contamination. Replace HO2S-11 and oil filter. Then go to Step 11.
9		No	Replace the PCM, then go to Step 11.
10	VERIFY WIRING IS IN PROPER PIN LOCATION • Measure resistance between PCM terminal 60 and 91 at PCM harness side connector. • Is the resistance less than 5.0 ohms?	Yes	Replace HO2S-11, then go to the next step.
10		No	Intermittent malfunction exist, go to the next step.
11	VERIFY TROUBLESHOOTING OF DTC P0133 COMPLETED • Make sure to reconnect all disconnected connectors. • Clear the DTC from the PCM memory using the WDS or equivalent. • Cruise the vehicle at 64 km/h {40 MPH} for at least 5 minutes. • Is the PENDING CODE same DTC present?	Yes	Replace PCM, then go to next step. (See PCM REMOVAL/INSTALLATION [YF (2.0L Zetec)].)
11		No	Go to next step.
12	VERIFY AFTER REPAIR PROCEDURE • Perform "After Repair Procedure". (See AFTER REPAIR PROCEDURE [YF (2.0L Zetec)].) • Is there any DTC present?	Yes	Go to applicable DTC inspection. (See DTC TABLE [YF (2.0L Zetec)].)
12		No	Troubleshooting completed.