https://kb.symtechlabs.com/ 2026-05-31T04:32:27+00:00 https://kb.symtechlabs.com/ https://kb.symtechlabs.com/lib/tpl/arctic/images/favicon.ico text/html 2012-01-18T17:38:03+00:00 https://kb.symtechlabs.com/io2ss:p0036?rev=1326908283&do=diff * Ensure the oxygen sensor’s heater circuit element is within the OEM’s specifications. * If using the heater circuit simulator included with the iO2SS, ensure it is connected to the correct wires. * Inspect the wiring harness for open or short circuits. * Ensure the oxygen sensor heater circuit’s fuse isn’t blown. * If this problem persists, there may be a problem with the engine control unit (ECU). text/html 2012-01-19T04:41:20+00:00 https://kb.symtechlabs.com/io2ss:p0037?rev=1326948080&do=diff * Ensure the oxygen sensor’s heater circuit element is within the OEM’s specifications. * If using the heater circuit simulator included with the iO2SS, ensure it is connected to the correct wires. * Inspect the wiring harness for open circuits. * Ensure the oxygen sensor heater circuit’s fuse isn’t blown. * If this problem persists, your car may require a lower resistance heater circuit simulator. In this case, contact support@symtechlabs.com for further support. text/html 2012-01-19T04:42:15+00:00 https://kb.symtechlabs.com/io2ss:p0038?rev=1326948135&do=diff * Ensure the oxygen sensor’s heater circuit element is within the OEM’s specifications. * If using the heater circuit simulator included with the iO2SS, ensure it is connected to the correct wires. * Inspect the wiring harness for short circuits. * Ensure the oxygen sensor heater circuit’s fuse isn’t blown. * If this problem persists, your car may require a higher resistance heater circuit simulator. In this case, contact support@symtechlabs.com for further support. text/html 2013-01-10T19:56:23+00:00 https://kb.symtechlabs.com/io2ss:p0041?rev=1357847783&do=diff * If using two separate iO2SS's in piggy-back mode, verify that each unit's output (green wire) is connected to the appropriate oxygen sensor signal wire leading to the PCM. Reverse the wires if the problem persists. * If using a single, dual output iO2SS in piggy-back mode, your car may require two individual single output iO2SS's instead. * If using an iO2SS in stand-alone mode and this error code occurs, contact support@symtechlabs.com for further support. text/html 2012-01-18T17:38:58+00:00 https://kb.symtechlabs.com/io2ss:p0054?rev=1326908338&do=diff * Ensure the oxygen sensor’s heater circuit element is within the OEM’s specifications. * If using the heater circuit simulator included with the iO2SS, ensure it is connected to the correct wires. * Inspect the wiring harness for open or short circuits. * Ensure the oxygen sensor heater circuit’s fuse isn’t blown. * If this problem persists, there may be a problem with the engine control unit (ECU). text/html 2013-01-10T19:48:19+00:00 https://kb.symtechlabs.com/io2ss:p0136?rev=1357847299&do=diff * Make sure the iO2SS is properly powered. Measure the unit's power input (red wire) when the engine is on; you should measure >12V. * Ensure the iO2SS's signal outputs (green wires) are connected to the appropriate oxygen sensor signal wires leading to the PCM. * Verify all other wiring and check all solder joints or crimp connectors for loose connections, frayed wires, or corrosion. * If using an iO2SS in stand-alone mode, adjust the offset potentiometer (OFF) to add voltage offset to t… text/html 2013-01-10T19:50:25+00:00 https://kb.symtechlabs.com/io2ss:p0137?rev=1357847425&do=diff * If using an iO2SS in stand-alone mode, adjust the offset potentiometer (OFF) to add voltage offset to the signal. * If using an iO2SS in piggy-back mode, your oxygen sensor may be damaged. Consider using the iO2SS in stand-alone mode instead. Return to iO2SS Page text/html 2013-01-10T19:51:05+00:00 https://kb.symtechlabs.com/io2ss:p0138?rev=1357847465&do=diff * If using an iO2SS in stand-alone mode, adjust the offset potentiometer (OFF) to remove voltage offset to the signal. * If using an iO2SS in piggy-back mode, your oxygen sensor may be damaged. Consider using the iO2SS in stand-alone mode instead. text/html 2013-01-10T19:54:31+00:00 https://kb.symtechlabs.com/io2ss:p0139?rev=1357847671&do=diff * If using an iO2SS in either stand-alone mode or piggy-back mode, simply adjust the frequency (FRQ) potentiometer to increase the period of the signal and eliminate this error code. Return to iO2SS Page text/html 2013-01-10T19:55:03+00:00 https://kb.symtechlabs.com/io2ss:p0140?rev=1357847703&do=diff * Make sure the iO2SS is properly powered. Measure the unit's power input (red wire) when the engine is on; you should measure >12V. * Ensure the iO2SS's signal outputs (green wires) are connected to the appropriate oxygen sensor signal wires leading to the PCM. * Verify all other wiring and check all solder joints or crimp connectors for loose connections, frayed wires, or corrosion. * If using an iO2SS in piggy-back mode, your oxygen sensor may be damaged. Consider using the iO2SS in st… text/html 2012-01-18T18:04:31+00:00 https://kb.symtechlabs.com/io2ss:p0141?rev=1326909871&do=diff * Make sure the iO2SS is properly powered. Measure the unit's power input (red wire) when the engine is on; you should measure >12V. * Ensure the iO2SS's signal outputs (green wires) are connected to the appropriate oxygen sensor signal wires leading to the PCM. * Verify all other wiring and check all solder joints or crimp connectors for loose connections, frayed wires, or corrosion. * Contact support@symtechlabs.com for further support. text/html 2013-01-10T19:56:58+00:00 https://kb.symtechlabs.com/io2ss:p0420?rev=1357847818&do=diff * If using an iO2SS in either piggy-back mode or stand-alone mode, simply adjust the frequency (FRQ) potentiometer to decrease the period of the signal and eliminate this error code. * If the problem persists, verify all other wiring and check all solder joints or crimp connectors for loose connections, frayed wires, or corrosion. text/html 2012-01-18T17:46:03+00:00 https://kb.symtechlabs.com/io2ss:start?rev=1326908763&do=diff FAQ Troubleshooting OBD-II Error Codes Sorted by Description * P0030/P0031/P0032/P0053 HO2S Heater Control Circuit (Bank 1, Sensor 1) * P0050/P0051/P0052/P0059 HO2S Heater Control Circuit (Bank 2, Sensor 1) * P0130/P0131/P0132/P0133/P0134/P0135 O2 Sensor Circuit (Bank 1, Sensor 1) * P0150/P0151/P0152/P0153/P0154/P0155 O2 Sensor Circuit (Bank 2, Sensor 1) text/html 2012-11-30T07:12:24+00:00 https://kb.symtechlabs.com/io2ss:upstream?rev=1354259544&do=diff These error codes have to do with upstream oxygen sensors. The SymTech Labs iO2SS is only for use with downstream sensors. If you installed an iO2SS in conjunction with or to replace an upstream oxygen sensor, remove it. Otherwise, follow normal troubleshooting procedures for upstream oxygen sensor problems. Return to iO2SS Page