Code Definitions
- DTC P1130: Air/Fuel Sensor Circuit Range/Performance Fault (Bank 1 Sensor 1)
- DTC P1150: Air/Fuel Sensor Circuit Range/Performance Fault (Bank 2 Sensor 1)
| CAUTION | If ECM replacement is instructed in following testing, always ensure ECM connectors and ground circuit are okay. If either are suspect, repair and repeat testing to confirm ECM malfunction. If ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. For programming procedures, see COMPUTER RELEARN PROCEDURES - IMPORT article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT. |
Note. Bank 1 is also known as right bank (RH).
Note. For component location, see appropriate illustration in THEORY & OPERATION article.
Circuit Description
Air/Fuel (A/F) sensor monitors exhaust gas oxygen content and delivers an input signal to ECM. ECM uses input signal to control air/fuel ratio. A/F sensor includes a heater. DTC P1130 is for bank No. 1 A/F sensor. DTC P1150 is for bank No. 2 A/F sensor. DTC is set when A/F sensor voltage output remains the same with engine running after engine is warmed to normal operating temperature. Possible causes are
- A/F sensor circuit is open or shorted.
- Defective A/F sensor.
- Air induction system malfunction.
- Improper fuel pressure.
- Defective fuel injector.
- Defective ECM.
Diagnostic Aids
After confirming DTC P1130 and/or P1150, use scan tool to access CURRENT DATA to confirm voltage output of A/F sensors (bank No. 1 and 2 sensor No. 1). ECM controls voltage of AFR+, AFL+, AFR- and AFL- terminals at ECM to a fixed voltage (3.3 volts at AFR+ and AFL+ terminals; 3.0 volts at AFR- and AFL- terminals). It is impossible to confirm A/F sensor output voltage without using a scan tool. A/F sensor output voltage on OBD II scan tools is displayed at one fifth the voltage of that displayed on Toyota hand-held tester. Using scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.
During fuel enrichment, output voltage of A/F sensors may be less than 0.56 volt (2.8 volts on Toyota hand-held tester). During fuel cut, output voltage of A/F sensors may be greater than 0.76 volt (3.8 volts on Toyota hand-held tester). If output voltage of A/F sensor remains at 0.66 volt (3.3 volts on Toyota hand-held tester) during all conditions, A/F sensor circuit may be open. If output voltage of A/F sensor remains at 0.76 volt (3.8 volts on Toyota hand-held tester) or more during all conditions, A/F sensor circuit may be shorted. If output voltage of A/F sensor remains at 0.56 volt (2.8 volts on Toyota hand-held tester) or less during all conditions, A/F sensor circuit may be shorted.