Vehicle applicability: This diagnostic supplement covers multiple Ford vehicles and engines. Follow the application named in the source below. Some references apply to vehicles other than Mustang.
DZ3 CHECK FOR MISFIRE CONCERNS AND AFTERMARKET EQUIPMENT
• Check for the following:
◾ misfire concern ◾ non-factory or aftermarket equipment that may increase the exhaust temperature
• Universal HO2S connector disconnected.
• Check the universal HO2S connector for damage or corrosion.
Is a concern present?
Yes | No |
|---|---|
REPAIR as necessary. Clear the PCM DTCs. REPEAT the self-test. | GO to DZ4 . |
DZ4 CHECK THE UO2SHTR CIRCUIT FOR A SHORT TO VOLTAGE
• PCM connector disconnected.
• Ignition ON, engine OFF.
• Measure the voltage between:
( + ) Universal HO2S Connector, Harness Side | ( - ) |
|---|---|
UO2SHTR | Ground |
Is any voltage present?
Yes | No |
|---|---|
REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test. | GO to DZ5 . |
DZ5 CHECK THE UO2S, UO2SGREF, UO2SHTR CIRCUITS FOR AN OPEN
• Ignition OFF.
• Measure the resistance between:
( + ) Universal HO2S Connector, Harness Side | ( - ) PCM Connector, Harness Side |
|---|---|
UO2S | UO2S |
UO2SGREF | UO2SGREF |
UO2SHTR | UO2SHTR |
Are the resistances less than 5 ohms?
Yes | No |
|---|---|
GO to DZ7 . | REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test. |
2016 Mustang workshop publication supplied to Mustang Atlas. Original technical text and illustrations; HTML formatting by Mustang Atlas. Source page numbering is retained for traceability. Follow the configuration, revision, warnings, and cross-references in the material. About this edition.