HEATED OXYGEN SENSOR (HO2S) DIAGNOSTIC
Two heated oxygen sensors (HO2S) are used in the Denso engine control module (ECM). The heated oxygen sensors (HO2S) are checked as usual for short-circuits and open-circuits. Diagnostic trouble code (DTC) ECM-2120 (front heated oxygen sensor (HO2S)) or ECM-2200 (rear heated oxygen sensor (HO2S)) will be stored if any of these faults occur. The probe heat elements are also checked. In the event of a fault, diagnostic trouble code (DTC) ECM-2110 (front heated oxygen sensor (HO2S), heating), ECM-2120 (front heated oxygen sensor (HO2S), probe control) or ECM-2210 (rear heated oxygen sensor (HO2S), heating) will be stored. In addition, probe control is also checked. In brief, these checks are carried out as follows.
The front heated oxygen sensor (HO2S)
The front heated oxygen sensor (HO2S), which is a linear type: Two checks where the switch over time between rich-lean and lean rich fuel / air mixture is checked. The diagnostic checks the response time of the front heated oxygen sensor (HO2S) when fuel shut-off is activated and deactivated.
The rich-lean check takes place when the fuel shut-off system is activated, on condition that the sensor current is below a lower limit (indicates rich fuel / air mixture). When the fuel shut-off system is activated, the sensor current usually rises (this indicates a lean fuel / air mixture). The lean-rich check measures the time taken for the sensor current to rise from a lower to an upper limit value. If the time counter exceeds a fault level without the sensor current having reached the upper limit value, the response is considered to be too slow; a fault marker is stored.
The lean-rich check is carried out in a similar way when the fuel shut-off system is deactivated. The difference is that the time taken for the sensor current to fall is measured. Diagnostic trouble code (DTC) ECM-210A (front heated oxygen sensor (HO2S)) is stored in the event of a fault in both of these checks.
In addition, the lambda value is also checked. This value must not deviate significantly from its control value. Diagnostic trouble code (DTC) ECM-210F (front heated oxygen sensor (HO2S)) is stored if the difference is too great.
Rear heated oxygen sensor (HO2S)
The rear heated oxygen sensor (HO2S), which is a binary type, is checked in the following way.
The control module checks the difference between the rear probe voltage maximum and minimum values. This voltage must not exceed 0.5 V. If the difference is greater, the control module takes an initialization value as its starting point. This is a maximum of 0 V and a minimum of 5 V. After this, the rear heated oxygen sensor (HO2S) maximum value must exceed the initialization value (0 V) for the probe voltage by at least 0.6 V and fall below the initialization value (5 V) probe voltage to the minimum value 0.1 V. If these limit values are not reached within approximately 5 minutes and the accumulated and actual probe warming has not reached certain limit values, the control module interprets it as a fault.
Twin probe control starts and is active when
- the front probe has started control
- the rear probe has reached operating temperature
Twin probe control is interrupted during fuel shut-off, during misfiring or in the event of a fault in
- the catalytic converter
- heated oxygen sensor (HO2S) heating
INFORMATION ABOUT COMBINED DIAGNOSTIC TROUBLE CODES (DTCS)
Combined diagnostic trouble codes (DTCs)
The following table is available to facilitate fault-tracing of ETM related diagnostic trouble codes (DTCs).
Note. Probable root diagnostic trouble codes (DTCs) are in bold and listed at the top of each cell.
Example of how to read table: If the codes 1300 and 904C are set, then 1300 is the likely root trouble code.
The diagnostic trouble codes (DTCs) can also be stored individually or together with other diagnostic trouble codes (DTCs) that do not affect ETM.
Note. There are two different tables, one for cars with upgraded software released during 2006 or later, and one for cars that are not upgraded with this software. See IDENTIFYING UPGRADED SOFTWARE ECM/ETM
| 1300 1300 904C | 9190 903C 903F 904C 904D 9190 91A7 91F0 | 981A 904D 981A |
|---|---|---|
| 6806 6806 904C | 91A7 91A7 91F0 | 981A 904C 904D 981A |
| 902A 902A 917F | 91A7 91A7 91B7 | E000 902A E000 |
| 902A 902A 903F | 91A7 903F 91A7 | E000 902A 912A E000 |
| 902A 902A 912A | 91A7 903F 904C 91A7 | E000 902A 903F 912A E000 |
| 902A 902A 928C | 9520 904D 917F 9520 958F | E000 903F 912A E000 |
| 902A 902A 903F 912A | 9520 904D 9180 9520 958F 959F | E000 912A E000 |
| 903F 903F 904C | 9520 904D 917F 9180 9520 958F | E003 902A E003 |
| 9150 9150 91A7 | 958F 904D 958F | E003 912A E003 |
| 9150 903C 903F 904D 9150 9160 91A7 | 958F 904D 958F 959F | E003 902A 912A E003 |
| 9160 9160 91A7 | 959F 917F 959F | E003 902A 928C E003 |
| 9190 903C 903F 904D 9190 91F0 | ||
| 9190 903C 903F 904D 9190 91A7 91F0 |
5/6-CYL TURBO AND 6-CYL NON-TURBO ENGINES, FOR UPGRADED SOFTWARE RELEASED DURING 2006 OR LATER
| 130A 130A 91CF | 9520 917F 9520 958F | 901E 901E 903C 903F |
|---|---|---|
| 91A7 904D 91A7 | 9150 9160 903C 903F 9150 9160 | 902A 902A 903F 904D |
| 9150 9160 903F 904C 904D 9150 9160 | 902A 902A 903F 959F | 9190 903F 904D 9190 91A7 |
| 9150 9160 903F 904C 904D 9150 9160 91A7 | 958F 958F 959F | 91B7 904D 91A7 91B7 |
| 902A 902A 903F 904D 959F | 9150 9160 903F 904C 9150 9160 | 982A 904D 982A |
| 9150 9160 903F 904C 904D 9150 9160 982A | 9150 9160 903F 904C 904D 9150 9160 91B7 | 958F 917F 958F |
| 91A7 903C 91A7 | 902A 903C 903F 959F | 9150 9160 903C 903F 9150 9160 91A7 |
| 91A7 903F 904D 91A7 | 9150 9160 902A 903F 904C 91A7 | 9150 9160 903F 904C 904D 9150 9160 91A7 91B7 |
| 901E 901E 903F | 981A 904D 981A | 902A 902A 928C |
| 903F 903F 904D | 130A 130A 904D 91A7 | |
| 130A 130A 903F 904D 91CF | 981A 6805 904D 981A |
5/6-CYL TURBO AND 6-CYL NON-TURBO ENGINES, FOR NON-UPGRADED SOFTWARE
SHUTTING OFF THE MISFIRE DIAGNOSTIC
Misfire diagnostics are shut off in the event of
- driveline oscillations. Drive line oscillations, caused by uneven road surfaces for example, may lead to uneven engine operation. Drive line oscillations will be posted by the ABS system and this information is sent to the engine control module (ECM). The engine control module (ECM) uses this information in order to differentiate between oscillations and actual misfiring and the diagnostic is shut off.
- diagnostic trouble codes (DTCs) in the flywheel sensor, mass air flow (MAF) sensor, ABS and camshaft position (CMP) sensor.