Return Spring Testing Not Performed (Ford) / Air-Fuel Ratio Sensor Circuit Malfunction (Nissan)
What does P1160 mean?
The P1160 code means the vehicle's onboard diagnostic system has detected: Return Spring Testing Not Performed (Ford) / Air-Fuel Ratio Sensor Circuit Malfunction (Nissan). This is a moderate severity code.
Common Symptoms
- Check Engine Light on
- Possible idle issues
- Failed emissions test
- Reduced throttle response (Ford)
- Poor fuel economy (Nissan)
Probable Causes (Ranked by Likelihood)
- Incomplete OBD-II readiness monitor cycle (Ford) Very High
- Faulty air-fuel ratio sensor (Nissan) High
- Throttle body return spring issue (Ford) Moderate
- Wiring fault in sensor circuit (Nissan) Moderate
- PCM/ECM programming issue Low
Step-by-Step Diagnostic Procedure
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Determine manufacturer -- Ford and Nissan define this code differently
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For Ford: complete the OBD-II drive cycle to allow readiness monitors to run
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For Nissan: test the air-fuel ratio sensor output with a scan tool
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Inspect throttle body operation and return spring (Ford)
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Check A/F sensor wiring and connector (Nissan)
Frequently Asked Questions
Why does P1160 mean different things on different vehicles?
P1xxx codes are manufacturer-specific. Each manufacturer can define codes from P1000 to P1999 as they choose. Always verify the definition for your specific vehicle make.
What is return spring testing on Ford?
On Ford vehicles, P1160 indicates the throttle return spring test (part of the OBD-II readiness monitors) has not completed. This often sets after a battery disconnect or PCM reset and clears after a complete drive cycle.
How do I complete a Ford drive cycle?
A Ford drive cycle typically involves a cold start, idle for several minutes, moderate acceleration to highway speed, cruise for several minutes, decelerate without braking, and idle again. The specific requirements vary by model year.