Oxygen sensor 1, bank 1, no signal
P1170 — Oxygen sensor 1, bank 1, no signal
System: Powertrain | Type: Manufacturer-Specific | Make: Ford
P1170 is a manufacturer-specific powertrain diagnostic trouble code recorded for Ford vehicles. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.
When P1170 is stored, the module has detected a bank-specific fault, meaning it applies only to one cylinder bank of a multi-bank engine; and a sensor-related fault — the reported value from the named sensor is out of spec.
Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.
P1170 is a manufacturer-specific code. The same code string on a different make may have a different meaning. Always confirm the code's definition against the vehicle's service information for the specific make and model under test.
The Powertrain Control Module (PCM) relies on the upstream oxygen sensor (sensor 1) on Bank 1 to provide a switching voltage signal that reflects exhaust oxygen content for closed loop fuel control. DTC P1170 sets when the PCM detects no usable signal from the Bank 1 sensor 1, meaning the sensor output is flat or absent rather than switching between rich and lean. Bank 1 is the cylinder bank that contains cylinder number 1, and sensor 1 sits ahead of the catalytic converter. A missing signal can result from an open or shorted sensor, a break in the wiring, a lost sensor ground or reference, or...
Detailed possible causes for P1170 are available to TaT members.
Unlock with Free TrialStep-by-step diagnostic guidance for P1170 is available to TaT members. Our Diagnostic Assistant provides professional-level troubleshooting procedures written by experienced technicians.
Unlock with Free Trial| Code | P1170 |
| System | Powertrain |
| Type | Manufacturer-Specific |
| Make | Ford |
| Causes | Available |
| Diag. Assistant | Available |
| Video | — |
Get complete diagnostic info, causes, and repair guidance.
Start Free 7-Day Trial Member LoginSearch all 8,602 fault codes with complete diagnostic details, possible causes, and repair guidance.
Start Your Free 7-Day Trial Member Login© 2026 The Automotive Technician (TaT) — www.tat.net.au