Current Too Low

ECM-2100 FRONT HEATED OXYGEN SENSOR (HO2S)
CURRENT TOO LOW

Diagnostic Trouble Code (DTC) status ECM-2100, Front Heated Oxygen Sensor (HO2S). Current too low
Reading Diagnostic Trouble Code (DTC) status ECM-2100



Note! When Reading the Diagnostic Trouble Code (DTC) status, other stored Diagnostic Trouble Codes (DTCs) and their status will be listed.

- Read the Diagnostic Trouble Code (DTC) status. Check the status of the relevant Diagnostic Trouble Code (DTC).

Was the status of the relevant Diagnostic Trouble Code (DTC) displayed as permanent?
Yes - Continue below.
No - Current Too Low - Intermittent Fault


Checking connector



- Ignition off.
- Check front Heated Oxygen Sensor (HO2S) connector for contact resistance and oxidation

Caution!
Do not apply rust solvent spray or grease to the Heated Oxygen Sensor (HO2S) connector.

If wiring is OK, try another Heated Oxygen Sensor (HO2S).

Other information
- To access/replace the heated oxygen sensor (HO2S), Heated Oxygen Sensor (HO2S), Replacing


Checking connector



- Ignition off.
- Reinstall components, reconnect connectors etc.
- Start the engine and let it idle.
- Read front Heated Oxygen Sensor (HO2S) signal.

Check that the signal is within its permitted range according to Pinout Values and Diagnostic Parameters
If signal is now OK this indicates that the fault was caused by poor contact in the connector.

Is the signal OK?
Yes - Skip to "Verification"
No - Continue below.


Checking wiring and components



Caution!
Do not apply rust solvent spray or grease to the Heated Oxygen Sensor (HO2S) connector.

Check signal cable (+) between control module # A42 (# A42) and Heated Oxygen Sensor (HO2S) connector terminal # 4 for an open-circuit according to [1][2]Checking Wiring and Terminals. Permanent Fault and for a short-circuit to ground according to [1][2]Checking Wiring and Terminals. Permanent Fault

Hint: With the ignition on and Heated Oxygen Sensor (HO2S) connector disconnected, the voltage between terminal # 4 and ground terminal should be approximately 0.1 V.

Check signal cable (-) between control module # A41 (# A41) and Heated Oxygen Sensor (HO2S) connector terminal 3 for an open-circuit according to [1][2]Checking Wiring and Terminals. Permanent Fault

If wiring is OK, try another Heated Oxygen Sensor (HO2S).

Remedy as necessary.

Other information
- To connect the breakout box, Connecting the Breakout Box (ECM)
- To access/replace the control module, Engine Control Module (ECM), Replacing
- To access/replace the heated oxygen sensor (HO2S), Heated Oxygen Sensor (HO2S), Replacing
- For information about signals, Pinout Values and Diagnostic Parameters


Verification



Hint: After carrying out the repair, check that the fault has been remedied.
- Ignition off.
- Reconnect the connectors, reinstall components etc.
- Start the engine and let it idle.
- Read front Heated Oxygen Sensor (HO2S) signal.

Check that the signal is within its permitted range according to Pinout Values and Diagnostic Parameters

Is the signal OK?
Yes - Testing Complete
No - Continue Below.


Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed.
Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.