Engine Control Module (ECM) Diagnostic Trouble Codes - 2 of 13: Diagnosis Volvo XC90 I

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-221C

Condition

Scheme 79

The engine control module (ECM) monitors the operation of the rear heated oxygen sensor (HO2S) by checking its signal. The engine control module (ECM) checks that the probe has registered a rich fuel/air mixture. If this is not the case, the engine control module (ECM) changes the fuel/air mixture. The diagnostic trouble code (DTC) is stored if the rear probe has still not registered a rich fuel / air mixture.

Substitute Value

1. None.

Possible Source

1. Leakage in the exhaust system
2. Damaged rear heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-221C

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-221D

Condition

The engine control module (ECM) monitors the operation of the rear heated oxygen sensor (HO2S) by checking its signal. The engine control module (ECM) checks that the probe has registered a lean fuel/air mixture. If this is not the case, the engine control module (ECM) changes the fuel/air mixture. The diagnostic trouble code (DTC) is stored if the rear probe has still not registered a lean fuel / air mixture.

Note. At fuel shut-off, the probe must show a lean fuel/air mixture. The diagnostic trouble code (DTC) is also stored if the switch-over time to a lean fuel/air mixture is too long.

Substitute Value

1. None.

Possible Source

1. Leakage in the exhaust system
2. Damaged rear heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-221D

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-2220

Condition

The engine control module (ECM) monitors the operation of the rear heated oxygen sensor (HO2S) by checking its signal. The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the signal deviates from its permitted operational range or if the voltage for the heated oxygen sensor (HO2S) preheating disrupts the heated oxygen sensor (HO2S) signal.

Substitute Value

1. Rear heated oxygen sensor (HO2S) control is disabled
2. Three-way catalytic converter (TWC) diagnostics are disabled.

Possible Source

1. Short-circuit in the signal cable for the pre-heating circuit
2. Short-circuit in the ground lead for the preheating circuit
3. Damaged rear heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-2220

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-222B

Condition

The engine control module (ECM) monitors the operation of the rear heated oxygen sensor (HO2S) by checking its signal. The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the signal deviates from its permitted operational range or if the voltage for the heated oxygen sensor (HO2S) preheating disrupts the heated oxygen sensor (HO2S) signal.

Substitute Value

1. Rear heated oxygen sensor (HO2S) control is disabled
2. Three-way catalytic converter (TWC) diagnostics are disabled.

Possible Source

1. Contact resistance or oxidation in the connectors
2. Open-circuit in the signal cable
3. Open-circuit in the ground lead
4. Damaged rear heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-222B

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-222C

Condition

The engine control module (ECM) monitors the operation of the rear heated oxygen sensor (HO2S) by checking its signal. The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the signal deviates from its permitted operational range or if the voltage for the heated oxygen sensor (HO2S) preheating disrupts the heated oxygen sensor (HO2S) signal.

Substitute Value

1. Rear heated oxygen sensor (HO2S) control is disabled
2. Three-way catalytic converter (TWC) diagnostics are disabled.

Possible Source

1. Short-circuit to supply voltage in the signal cable
2. Short-circuit to supply voltage in the ground lead
3. Damaged rear heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-222C

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-222D

Condition

The engine control module (ECM) monitors the operation of the rear heated oxygen sensor (HO2S) by checking its signal. The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the signal deviates from its permitted operational range or if the voltage for the heated oxygen sensor (HO2S) preheating disrupts the heated oxygen sensor (HO2S) signal.

Substitute Value

1. Rear heated oxygen sensor (HO2S) control is disabled
2. Three-way catalytic converter (TWC) diagnostics are disabled.

Possible Source

1. Short-circuit to ground in the signal cable
2. Short-circuit to ground in the ground lead
3. Damaged rear heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-222D

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-223B

Condition

The engine control module (ECM) controls the preheating of the rear heated oxygen sensor (HO2S) by pulsing the current to the positive temperature coefficient (PTC) element in the heated oxygen sensor (HO2S). Pulse lengths are dependent on the temperature of the heated oxygen sensor (H02S).

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the signal is lower than a certain value when preheating is deactivated.

Substitute Value

1. The fuel trim is shut off.

Possible Source

1. Contact resistance and oxidation in the terminals
2. Open-circuit in the power supply from the system relay
3. Damaged heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-223B

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-223C

Condition

The engine control module (ECM) controls the preheating of the rear heated oxygen sensor (HO2S) by pulsing the current to the positive temperature coefficient (PTC) element in the heated oxygen sensor (HO2S). Pulse lengths are dependent on the temperature of the heated oxygen sensor (H02S).

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the signal is higher than a certain value when preheating is active.

Substitute Value

1. The fuel trim is shut off.

Possible Source

1. Short-circuit to supply voltage in the signal cable
2. Damaged heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-223C

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-223D

Condition

The engine control module (ECM) controls the preheating of the rear heated oxygen sensor (HO2S) by pulsing the current to the positive temperature coefficient (PTC) element in the heated oxygen sensor (HO2S). Pulse lengths are dependent on the temperature of the heated oxygen sensor (H02S).

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the signal is lower than a certain value when preheating is deactivated.

Substitute Value

1. The fuel trim is shut off.

Possible Source

1. Short-circuit to ground in the signal cable
2. Damaged heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-223D

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-2240

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) detects that the rear heated oxygen sensors (HO2S) (banks 1 and 2) have been switched.

The diagnostic trouble code (DTC) is diagnosed when the engine has been idling for 10 minutes.

Substitute Value

1. The heated oxygen sensor (HO2S) control is disabled
2. Three-way catalytic converter (TWC) diagnostics are disabled.

Possible Source

1. The rear heated oxygen sensors (HO2S) have been installed in the wrong bank
2. Both the rear heated oxygen sensors (HO2S) are damaged.

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-2240

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-2300

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the resistance of the rear right heated oxygen sensor (HO2S) in the pre-heating circuit is too high for a certain amount of time.

Substitute Value

None.

Possible Source

1. Contact resistance or oxidation in the terminals
2. Damaged rear heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION

Condition

Scheme 80

Diagnostic trouble code (DTC) ECM-23X0 is stored if the signal from the injector is too high, too low or missing.

Substitute Value

None

Possible Source

Signal too high

1. short-circuit to supply voltage in the signal cable
2. defective injector

Signal too low

1. short-circuit to ground in the signal cable

Signal missing

1. open-circuit in the signal cable
2. open-circuit in power supply to injector
3. defective injector
4. contact resistance in terminals

Fault symptom[s]

1. engine not firing on all cylinders
2. malfunction indicator lamp (MIL) lit

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION

Scheme 81

1. Ignition off
2. Check the injector connector. Check for contact resistance and oxidation
3. Reinstall the components, reconnect the connectors etc.
4. Ignition on
5. Activate the injector. A "click" should be heard when the injector is activated. If the injector is now OK, the fault was caused by poor contact in the connector. Other information For B5xx4T, see «INJECTOR/PULSE DAMPER, REPLACEMENT»(ref-476751-S12739566552012060500000) For B6xx4T, see «INJECTOR / PULSATION DAMPER, REPLACING»(ref-476751-S42918859582012060500000). For 5 cylinder turbocharged engines -2004, see «SIGNAL DESCRIPTION»(/volvo/xc90/i-2002-2006/remont/engine-control-systems/#engine-control-signal-description-and-specification) For 5 cylinder turbocharged engines 2005-, see «SIGNAL SPECIFICATION»(/volvo/xc90/i-2002-2006/remont/engine-control-systems/#engine-control-signal-description-and-specification). see «CHECKING WIRING AND TERMINALS»(/volvo/xc90/i-2002-2006/remont/body-electrical/#wiring-and-terminals-general-diagnostics-and-tests__contents).

Is the injector working?

1. YES OKAY: Troubleshooting has been completed.
2. NO Refer to «CHECKING COMPONENTS AND WIRING»(ref-476756-S42782387552012060500000)

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-231B

Condition

The engine control module (ECM) monitors the function of the rear heated oxygen sensor (HO2S) (bank 2) by checking its signal.

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) does not register a signal from the rear heated oxygen sensor (HO2S).

Substitute Value

1. None.

Possible Source

1. Damaged rear heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-231C

Condition

The engine control module (ECM) monitors the function of the rear heated oxygen sensor (HO2S) (bank 2) by checking its signal. The engine control module (ECM) checks that the probe has registered a rich fuel/air mixture. If this is not the case, the engine control module (ECM) changes the fuel/air mixture. The diagnostic trouble code (DTC) is stored if the rear probe has still not registered a rich fuel / air mixture.

Substitute Value

1. None.

Possible Source

1. Leakage in the exhaust system
2. Damaged rear heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-231D

Condition

The engine control module (ECM) monitors the function of the rear heated oxygen sensor (HO2S) (bank 2) by checking its signal. The engine control module (ECM) checks that the probe has registered a lean fuel/air mixture. If this is not the case, the engine control module (ECM) changes the fuel/air mixture. The diagnostic trouble code (DTC) is stored if the rear probe has still not registered a lean fuel / air mixture.

Note. At fuel shut-off, the probe must show a lean fuel/air mixture. The diagnostic trouble code (DTC) is also stored if the switch-over time to a lean fuel/air mixture is too long.

Substitute Value

1. None.

Possible Source

1. Leakage in the exhaust system
2. Damaged rear heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-2320

Condition

The engine control module (ECM) monitors the function of the rear heated oxygen sensor (HO2S) (bank 2) by checking its signal. The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the signal deviates from its permitted operational range or if the voltage for the heated oxygen sensor (HO2S) preheating disrupts the heated oxygen sensor (HO2S) signal.

Substitute Value

1. Rear heated oxygen sensor (HO2S) control is disabled
2. Three-way catalytic converter (TWC) diagnostics are disabled.

Possible Source

1. Short-circuit in the signal cable for the pre-heating circuit
2. Short-circuit in the ground lead for the preheating circuit
3. Damaged rear heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-232B

Condition

The engine control module (ECM) monitors the function of the rear heated oxygen sensor (HO2S) (bank 2) by checking its signal. The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the signal deviates from its permitted operational range or if the voltage for the heated oxygen sensor (HO2S) preheating disrupts the heated oxygen sensor (HO2S) signal.

Substitute Value

1. Rear heated oxygen sensor (HO2S) control is disabled
2. Three-way catalytic converter (TWC) diagnostics are disabled.

Possible Source

1. Contact resistance or oxidation in the connectors
2. Open-circuit in the signal cable
3. Open-circuit in the ground lead
4. Damaged rear heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-232C

Condition

The engine control module (ECM) monitors the function of the rear heated oxygen sensor (HO2S) (bank 2) by checking its signal. The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the signal deviates from its permitted operational range or if the voltage for the heated oxygen sensor (HO2S) preheating disrupts the heated oxygen sensor (HO2S) signal.

Substitute Value

1. Rear heated oxygen sensor (HO2S) control is disabled
2. Three-way catalytic converter (TWC) diagnostics are disabled.

Possible Source

1. Short-circuit to supply voltage in the signal cable
2. Short-circuit to supply voltage in the ground lead
3. Damaged rear heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-232D

Condition

The engine control module (ECM) monitors the function of the rear heated oxygen sensor (HO2S) (bank 2) by checking its signal. The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the signal deviates from its permitted operational range or if the voltage for the heated oxygen sensor (HO2S) preheating disrupts the heated oxygen sensor (HO2S) signal.

Substitute Value

1. Rear heated oxygen sensor (HO2S) control is disabled
2. Three-way catalytic converter (TWC) diagnostics are disabled.

Possible Source

1. Short-circuit to ground in the signal cable
2. Short-circuit to ground in the ground lead
3. Damaged rear heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-233B

Condition

The engine control module (ECM) controls preheating by pulsing the current to the positive temperature coefficient (PTC) element in the heated oxygen sensor (HO2S). Pulse lengths are dependent on the temperature of the heated oxygen sensor (H02S).

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the signal is lower than a certain value when preheating is deactivated.

Substitute Value

1. The fuel trim is shut off.

Possible Source

1. Contact resistance and oxidation in the terminals
2. Open-circuit in the power supply from the system relay
3. Damaged heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

Scheme 82

1. Start the engine. Read off the diagnostic status and fault status for the diagnostic trouble code (DTC) by selecting the relevant diagnostic trouble code (DTC) from the list. Increase the engine speed to 2500 RPM until the diagnostic is "Complete". Check whether the fault is permanent or intermittent. Read off the diagnostic trouble code (DTC) fault status when the diagnostic status is "Completed". HINT: In some cases several functions of the component will be diagnosed. The affects the amount of time taken to run the diagnostic. The fault is permanent if the fault status is "Fault found". If the fault status is "No fault found" the fault is intermittent and not presently active.

1. Continue Refer to «CHECKING THE COMPONENTS AND WIRING»(ref-476756-S39876057792012060500000)

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-233C

Condition

The engine control module (ECM) controls preheating by pulsing the current to the positive temperature coefficient (PTC) element in the heated oxygen sensor (HO2S). Pulse lengths are dependent on the temperature of the heated oxygen sensor (H02S).

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the signal is higher than a certain value when preheating is active.

Substitute Value

1. The fuel trim is shut off.

Possible Source

1. Short-circuit to supply voltage in the signal cable
2. Damaged heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-233D

Condition

The engine control module (ECM) controls preheating by pulsing the current to the positive temperature coefficient (PTC) element in the heated oxygen sensor (HO2S). Pulse lengths are dependent on the temperature of the heated oxygen sensor (H02S).

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the signal is lower than a certain value when preheating is deactivated.

Substitute Value

1. The fuel trim is shut off.

Possible Source

1. Short-circuit to ground in the signal cable
2. Damaged heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-2400

Condition

Scheme 83

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the front heated oxygen sensor (HO2S) (bank 1) has not reached normal operating temperature.

Substitute Value

1. None.

Possible Source

1. Contact resistance and oxidation in the terminals
2. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-2400

Condition

Scheme 84

Normally the Control area network (CAN) is used to transfer information about fuel pump control from the engine control module (ECM) to the central electronic module. The signal cable from the engine control module (ECM) to the Central electronic module is used for a "limp home" function when there is no Controller Area Network function.

Diagnostic trouble code (DTC) ECM-2400 is stored in the engine control module (ECM) if the engine control module (ECM) registers a fault in signal cable to the central electrical unit.

Substitute Value

None.

Possible Source

Signal too high

1. Short-circuit to supply voltage in the signal cable.

Signal too low

1. Short-circuit to ground in the signal cable.

Signal missing

1. Open-circuit in the signal cable.

Fault symptom[s]

1. None.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-240B

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that there has been no control of the heater element for the front heated oxygen sensor (HO2S) (bank 1) for a certain amount of time.

Substitute Value

1. None.

Possible Source

1. Contact resistance and oxidation in the terminals
2. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-240B

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-240C

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the resistance in the preheating circuit for the front heated oxygen sensor (HO2S) (bank 1) is too high.

Substitute Value

1. None.

Possible Source

1. Contact resistance and oxidation in the terminals
2. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-240C

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-242D

Condition

The engine control module (ECM) monitors the aging of the front heated oxygen sensor (HO2S) by checking its ability to react to changes in the exhaust gases. The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the heated oxygen sensor (HO2S) reacts too slowly to changes in the fuel/air mixture.

Substitute Value

1. Three-way catalytic converter (TWC) diagnostics are disabled.

Possible Source

1. The cables for the calibration current and the pump current are short-circuited to each other
2. Open-circuit in signal cable (-)
3. Open-circuit in the cable for calibration current
4. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-242D

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-243B

Condition

The engine control module (ECM) monitors the function of the front heated oxygen sensor (HO2S) (bank 1) by checking its signal. The diagnostic trouble code (DTC) is stored if the voltage for the heated oxygen sensor (HO2S) preheating disrupts the heated oxygen sensor (HO2S) signal.

Substitute Value

1. The heated oxygen sensor (HO2S) control is disabled
2. Three-way catalytic converter (TWC) diagnostics are disabled.

Possible Source

1. One of the cables for heated oxygen sensor (HO2S) preheating is short-circuited to the probe's other signal cables
2. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-243B

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-243C

Condition

Scheme 85

The engine control module (ECM) controls the resistance on the preheating circuit in the front lambda probe. The check is made by the control module measuring the current through the circuit and then converting the current to temperature. The diagnostic trouble code (DTC) is stored and it is interpreted as a fault if the control module detects that the resistance is unreasonably high, which results in a low temperature.

The diagnostic trouble code (DTC) can be diagnosed when driving.

Substitute Value

1. None.

Possible Source

1. Contact resistance and oxidation in the terminals.
2. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator light (MIL), on

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-243C

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-244B

Condition

The engine control module (ECM) controls preheating by pulsing the current to the positive temperature coefficient (PTC) element in the front heated oxygen sensor (HO2S). Pulse lengths are dependent on the temperature of the heated oxygen sensor (H02S).

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the signal is lower than a certain value when preheating is deactivated.

Substitute Value

1. Heated oxygen sensor (HO2S) control is disabled.

Possible Source

1. Contact resistance and oxidation in the terminals
2. Open-circuit in the power supply from the system relay
3. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-244B

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-244C

Condition

The engine control module (ECM) controls preheating by pulsing the current to the positive temperature coefficient (PTC) element in the front heated oxygen sensor (HO2S). Pulse lengths are dependent on the temperature of the heated oxygen sensor (H02S).

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the signal is higher than a certain value when preheating is active.

Substitute Value

1. Heated oxygen sensor (HO2S) control is disabled.

Possible Source

1. Short-circuit to supply voltage in the signal cable
2. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-244C

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-244D

Condition

The engine control module (ECM) controls preheating by pulsing the current to the positive temperature coefficient (PTC) element in the front heated oxygen sensor (HO2S). Pulse lengths are dependent on the temperature of the heated oxygen sensor (H02S).

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the signal is lower than a certain value when preheating is deactivated.

Substitute Value

1. Heated oxygen sensor (HO2S) control is disabled.

Possible Source

1. Short-circuit to ground in the signal cable
2. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-244D

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-2450

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers an internal fault in the control for the heated oxygen sensors (HO2S).

The diagnostic trouble code (DTC) can be diagnosed when the ignition is switched on.

Substitute Value

1. None.

Possible Source

1. Damaged engine control module (ECM).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-2450

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-245B

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers an internal fault in the control for the heated oxygen sensors (HO2S).

The diagnostic trouble code (DTC) can be diagnosed when the ignition is switched on.

Substitute Value

1. None.

Possible Source

1. Damaged engine control module (ECM).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-245B

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-245C

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers an internal fault in the control for the heated oxygen sensors (HO2S).

The diagnostic trouble code (DTC) can be diagnosed when the ignition is switched on.

Substitute Value

1. None.

Possible Source

1. Damaged engine control module (ECM).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-245C

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-245D

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers an internal fault in the control for the heated oxygen sensors (HO2S).

The diagnostic trouble code (DTC) can be diagnosed when the ignition is switched on.

Substitute Value

1. None.

Possible Source

1. Damaged engine control module (ECM).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-245D

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-246B

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the calibration current has ceased and the front heated oxygen sensor (HO2S) signal (bank 1) is implausibly high at fuel shut-off.

Substitute Value

1. None.

Possible Source

1. Contact resistance and oxidation in the terminals
2. Open-circuit in the cable for calibration current
3. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-246B

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-2470

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the pump current has ceased and the front heated oxygen sensor (HO2S) signal (bank 1) has been set to a default value.

Substitute Value

1. None.

Possible Source

1. Contact resistance and oxidation in the terminals
2. Open-circuit in the cable for pump current
3. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-2470

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-247B

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the pump current has ceased and the front heated oxygen sensor (HO2S) signal (bank 1) has been set to a default value.

Substitute Value

1. None.

Possible Source

1. Contact resistance and oxidation in the terminals
2. Open-circuit in the cable for pump current
3. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-247B

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-247C

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the pump current has ceased and the front heated oxygen sensor (HO2S) signal (bank 1) has been set to a default value.

Substitute Value

1. None.

Possible Source

1. Contact resistance and oxidation in the terminals
2. Open-circuit in the cable for pump current
3. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-247C

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-248C

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that there is a short-circuit to supply voltage in the signal cables for the front heated oxygen sensor (HO2S) (bank 1).

Substitute Value

1. None.

Possible Source

1. Short-circuit in the signal cables
2. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-248C

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-248D

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that there is a short-circuit to ground in the signal cables for the front heated oxygen sensor (HO2S) (bank 1).

Substitute Value

1. None.

Possible Source

1. Short-circuit in the signal cables
2. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-248D

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-249B

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers an open-circuit in the signal cable to the section of the front heated oxygen sensor (HO2S) (bank 1) that detects the oxygen content of the exhaust gases.

Substitute Value

1. None.

Possible Source

1. Contact resistance or oxidation on the signal cable
2. Open-circuit in the signal cable
3. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-249B

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-24A0

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) detects that the front heated oxygen sensors (HO2S) (bank 1 and bank 2) have been switched. This means they are installed in the incorrect bank of cylinders.

The diagnostic trouble codes (DTCs) are diagnosed when the engine has been idling for 10 minutes

Substitute Value

1. The heated oxygen sensor (HO2S) control is disabled
2. Three-way catalytic converter (TWC) diagnostics are disabled.

Possible Source

1. The front heated oxygen sensors (HO2S) are mounted in the incorrect cylinder banks
2. Leakage in the fuel injection system
3. Both the front heated oxygen sensors (HO2S) are damaged.

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

Scheme 86

1. Ignition off
2. Check that the front heated oxygen sensors (HO2S) bank 1 and bank 2 have not been switched (mounted in the incorrect bank of cylinders)
3. Remedy as necessary. Other information: For B5xx4T, see «HEATED OXYGEN SENSOR (HO2S), REPLACING»(ref-476768-S23777230272012060500000) For B6xx4T, see «HEATED OXYGEN SENSOR (HO2S), REPLACING»(ref-476768-S05984728352012060500000).

Have the heated oxygen sensors (HO2S) been switched?

1. YES Refer to «VERIFICATION»(ref-476756-S00561213852012060500000)
2. NO Refer to «CHECKING THE FUEL INJECTION SYSTEM FOR LEAKAGE»(ref-476756-S29552583312012060500000)

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-24AB

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers an open-circuit in the ground lead for the front heated oxygen sensor (HO2S) (bank 1).

Substitute Value

None.

Possible Source

1. Open-circuit in the ground lead
2. Damaged front heated oxygen sensor (HO2S) (bank 1).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-24AB

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-24B0

Condition

The engine control module (ECM) monitors the function of the front heated oxygen sensor (HO2S) (bank 1) by checking its signal. The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the signal from the heated oxygen sensor (HO2S) indicates an incorrect lean or rich fuel/air mixture compared to that anticipated by the engine control module (ECM).

Note. The fault may be in the front or rear heated oxygen sensor (HO2S) circuit.

Substitute Value

1. Long-term fuel trim is switched off
2. Three-way catalytic converter (TWC) diagnostics are disabled.

Possible Source

1. Leakage in the exhaust system
2. Short-circuit to supply voltage or ground in signal cable (-)
3. Short-circuit to supply voltage or ground in the pump supply cable
4. Short-circuit to supply voltage or ground in calibration supply cable
5. Open-circuit in signal cable (+)
6. Damaged heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-24B0

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-24BB

Condition

The engine control module (ECM) monitors the function of the front heated oxygen sensor (HO2S) (bank 1) by checking its signal. The engine control module (ECM) compares the adaptation values of the front and rear heated oxygen sensor (HO2S). The diagnostic trouble code (DTC) is stored when the values deviate by more than 3%.

Note. The fault may be in the front or rear heated oxygen sensor (HO2S) circuit.

Substitute Value

1. Long-term fuel trim is switched off
2. Three-way catalytic converter (TWC) diagnostics are disabled.

Possible Source

1. Leakage in the exhaust system
2. Heated oxygen sensor (HO2S) indicates an incorrectly rich fuel/air mixture
3. Contact resistance or oxidation in the terminals
4. Damaged heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-24BB

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-24BC

Condition

The engine control module (ECM) monitors the function of the front heated oxygen sensor (HO2S) (bank 1) by checking its signal. The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the signal from the front heated oxygen sensor (HO2S) indicates a rich fuel/air mixture while the signal from the rear heated oxygen sensor (HO2S) indicates a lean fuel/air mixture.

Note. The fault may be in the front or rear heated oxygen sensor (HO2S) circuit.

Substitute Value

1. Long-term fuel trim is switched off
2. Three-way catalytic converter (TWC) diagnostics are disabled.

Possible Source

1. Leakage in the exhaust system
2. Heated oxygen sensor (HO2S) indicates an incorrectly lean fuel/air mixture
3. Damaged heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-24BC

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-24BD

Condition

The engine control module (ECM) monitors the function of the front heated oxygen sensor (HO2S) (bank 1) by checking its signal. The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the signal from the front heated oxygen sensor (HO2S) indicates a lean fuel/air mixture while the signal from the rear heated oxygen sensor (HO2S) indicates a rich fuel/air mixture.

Note. The fault may be in the front or rear heated oxygen sensor (HO2S) circuit.

Substitute Value

1. Long-term fuel trim is switched off
2. Three-way catalytic converter (TWC) diagnostics are disabled.

Possible Source

1. Leakage in the exhaust system
2. Heated oxygen sensor (HO2S) indicates an incorrectly rich fuel/air mixture
3. Damaged heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-24BD

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-24C0

Condition

The engine control module (ECM) monitors the function of the front heated oxygen sensor (HO2S) (bank 1) by checking its signal. The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the heated oxygen sensor (HO2S) only indicates air and no fuel/air mixture.

Substitute Value

1. Long-term fuel trim is switched off
2. Three-way catalytic converter (TWC) diagnostics are disabled.

Possible Source

1. Incorrectly installed heated oxygen sensor (HO2S)
2. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-24C0

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-2500

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the front heated oxygen sensor (HO2S) (bank 2) has not reached normal operating temperature.

Substitute Value

1. None.

Possible Source

1. Contact resistance and oxidation in the terminals
2. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-250B

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that there has been no control of the heater element for the front heated oxygen sensor (HO2S) (bank 2) for a certain amount of time.

Substitute Value

1. None.

Possible Source

1. Contact resistance and oxidation in the terminals
2. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-250C

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the resistance in the preheating circuit for the front heated oxygen sensor (HO2S) (bank 2) is too high.

Substitute Value

1. None.

Possible Source

1. Contact resistance and oxidation in the terminals
2. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-250D

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the resistance in the preheating circuit for the front heated oxygen sensor (HO2S) (bank 2) is too low.

Substitute Value

1. None.

Possible Source

1. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-252D

Condition

The engine control module (ECM) monitors the aging of the front heated oxygen sensor (HO2S) by checking its ability to react to changes in the exhaust gases. The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the heated oxygen sensor (HO2S) reacts too slowly to changes in the fuel/air mixture.

Substitute Value

1. Three-way catalytic converter (TWC) diagnostics are disabled.

Possible Source

1. The cables for the calibration current and the pump current are short-circuited to each other
2. Open-circuit in signal cable (-)
3. Open-circuit in the cable for calibration current
4. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-253B

Condition

The engine control module (ECM) monitors the function of the front heated oxygen sensor (HO2S) (bank 2) by checking its signal. The diagnostic trouble code (DTC) is stored if the voltage for the heated oxygen sensor (HO2S) preheating disrupts the heated oxygen sensor (HO2S) signal.

Substitute Value

1. The heated oxygen sensor (HO2S) control is disabled
2. Three-way catalytic converter (TWC) diagnostics are disabled.

Possible Source

1. One of the cables for heated oxygen sensor (HO2S) preheating is short-circuited to the probe's other signal cables
2. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-254B

Condition

The engine control module (ECM) regulates preheating by pulsing the current to the positive temperature coefficient (PTC) element (bank 2) in the front heated oxygen sensor (HO2S). Pulse lengths are dependent on the temperature of the heated oxygen sensor (H02S).

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the signal is lower than a certain value when preheating is deactivated.

Substitute Value

1. Heated oxygen sensor (HO2S) control is disabled.

Possible Source

1. Contact resistance and oxidation in the terminals
2. Open-circuit in the power supply from the system relay
3. Damaged front heated oxygen sensor (HO2S) (bank 2).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-254C

Condition

The engine control module (ECM) regulates preheating by pulsing the current to the positive temperature coefficient (PTC) element (bank 2) in the front heated oxygen sensor (HO2S). Pulse lengths are dependent on the temperature of the heated oxygen sensor (H02S).

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the signal is higher than a certain value when preheating is active.

Substitute Value

1. Heated oxygen sensor (HO2S) control is disabled.

Possible Source

1. Short-circuit to supply voltage in the signal cable
2. Damaged front heated oxygen sensor (HO2S) (bank 2).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-254D

Condition

The engine control module (ECM) regulates preheating by pulsing the current to the positive temperature coefficient (PTC) element (bank 2) in the front heated oxygen sensor (HO2S). Pulse lengths are dependent on the temperature of the heated oxygen sensor (H02S).

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the signal is lower than a certain value when preheating is deactivated.

Substitute Value

1. Heated oxygen sensor (HO2S) control is disabled.

Possible Source

1. Short-circuit to ground in the signal cable
2. Damaged front heated oxygen sensor (HO2S) (bank 2).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-2550

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers an internal fault in the control for the heated oxygen sensors (HO2S).

The diagnostic trouble code (DTC) can be diagnosed when the ignition is switched on.

Substitute Value

1. None.

Possible Source

1. Damaged engine control module (ECM).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-255B

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers an internal fault in the control for the heated oxygen sensors (HO2S).

The diagnostic trouble code (DTC) can be diagnosed when the ignition is switched on.

Substitute Value

1. None.

Possible Source

1. Damaged engine control module (ECM).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-255C

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers an internal fault in the control for the heated oxygen sensors (HO2S).

The diagnostic trouble code (DTC) can be diagnosed when the ignition is switched on.

Substitute Value

1. None.

Possible Source

1. Damaged engine control module (ECM).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-255D

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers an internal fault in the control for the heated oxygen sensors (HO2S).

The diagnostic trouble code (DTC) can be diagnosed when the ignition is switched on.

Substitute Value

1. None.

Possible Source

1. Damaged engine control module (ECM).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-256B

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the calibration current has ceased and the front heated oxygen sensor (HO2S) signal (bank 2) is implausibly high at fuel shut-off.

Substitute Value

1. None.

Possible Source

1. Contact resistance and oxidation in the terminals
2. Open-circuit in the cable for calibration current
3. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-2570

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the pump current has ceased and the front heated oxygen sensor (HO2S) signal (bank 2) has been set to a default value.

Substitute Value

1. None.

Possible Source

1. Contact resistance and oxidation in the terminals
2. Open-circuit in the cable for pump current
3. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-257B

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the pump current has ceased and the front heated oxygen sensor (HO2S) signal (bank 2) has been set to a default value.

Substitute Value

1. None.

Possible Source

1. Contact resistance and oxidation in the terminals
2. Open-circuit in the cable for pump current
3. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-257C

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the pump current has ceased and the front heated oxygen sensor (HO2S) signal (bank 2) has been set to a default value.

Substitute Value

1. None.

Possible Source

1. Contact resistance and oxidation in the terminals
2. Open-circuit in the cable for pump current
3. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-258C

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that there is a short-circuit to supply voltage in the signal cables for the front heated oxygen sensor (HO2S) (bank 2).

Substitute Value

1. None.

Possible Source

1. Short-circuit in the signal cables
2. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-258D

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that there is a short-circuit to ground in the signal cables for the front heated oxygen sensor (HO2S) (bank 2).

Substitute Value

1. None.

Possible Source

1. Short-circuit in the signal cables
2. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-259B

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers an open-circuit in the signal cable to the section of the front heated oxygen sensor (HO2S) (bank 2) that detects the oxygen content of the exhaust gases.

Substitute Value

1. None.

Possible Source

1. Contact resistance or oxidation on the signal cable
2. Open-circuit in the signal cable
3. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-25AB

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers an open-circuit in the ground lead for the front heated oxygen sensor (HO2S) (bank 2).

Substitute Value

1. None.

Possible Source

1. Open-circuit in the ground lead
2. Damaged front heated oxygen sensor (HO2S) (bank 2).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-25B0

Condition

The engine control module (ECM) monitors the function of the front heated oxygen sensor (HO2S) (bank 2) by checking its signal. The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the signal from the heated oxygen sensor (HO2S) indicates an incorrect lean or rich fuel/air mixture compared to that anticipated by the engine control module (ECM).

Note. The fault may be in the front or rear heated oxygen sensor (HO2S) circuit.

Substitute Value

1. The heated oxygen sensor (HO2S) control is disabled
2. Three-way catalytic converter (TWC) diagnostics are disabled.

Possible Source

1. Leakage in the exhaust system
2. Short-circuit to supply voltage or ground in signal cable (-)
3. Short-circuit to supply voltage or ground in the pump supply cable
4. Short-circuit to supply voltage or ground in calibration supply cable
5. Open-circuit in signal cable (+)
6. Damaged heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-25BB

Condition

The engine control module (ECM) monitors the function of the front heated oxygen sensor (HO2S) (bank 2) by checking its signal. The engine control module (ECM) compares the adaptation values of the front and rear heated oxygen sensor (HO2S). The diagnostic trouble code (DTC) is stored when the values deviate by more than 3%.

Note. The fault may be in the front or rear heated oxygen sensor (HO2S) circuit.

Substitute Value

1. The heated oxygen sensor (HO2S) control is disabled
2. Three-way catalytic converter (TWC) diagnostics are disabled.

Possible Source

1. Leakage in the exhaust system
2. Heated oxygen sensor (HO2S) indicates an incorrectly rich fuel/air mixture
3. Contact resistance or oxidation in the terminals
4. Damaged heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-25BC

Condition

The engine control module (ECM) monitors the function of the front heated oxygen sensor (HO2S) (bank 2) by checking its signal. The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the signal from the front heated oxygen sensor (HO2S) indicates a rich fuel/air mixture while the signal from the rear heated oxygen sensor (HO2S) indicates a lean fuel/air mixture.

Note. The fault may be in the front or rear heated oxygen sensor (HO2S) circuit.

Substitute Value

1. The heated oxygen sensor (HO2S) control is disabled
2. Three-way catalytic converter (TWC) diagnostics are disabled.

Possible Source

1. Leakage in the exhaust system
2. Heated oxygen sensor (HO2S) indicates an incorrectly lean fuel/air mixture
3. Damaged heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-25BD

Condition

The engine control module (ECM) monitors the function of the front heated oxygen sensor (HO2S) (bank 2) by checking its signal. The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the signal from the front heated oxygen sensor (HO2S) indicates a lean fuel/air mixture while the signal from the rear heated oxygen sensor (HO2S) indicates a rich fuel/air mixture.

Note. The fault may be in the front or rear heated oxygen sensor (HO2S) circuit.

Substitute Value

1. The heated oxygen sensor (HO2S) control is disabled
2. Three-way catalytic converter (TWC) diagnostics are disabled.

Possible Source

1. Leakage in the exhaust system
2. Heated oxygen sensor (HO2S) indicates an incorrectly rich fuel/air mixture
3. Damaged heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION ECM-25C0

Condition

The engine control module (ECM) monitors the function of the front heated oxygen sensor (HO2S) (bank 2) by checking its signal. The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers that the heated oxygen sensor (HO2S) only indicates air and no fuel/air mixture.

Substitute Value

1. The heated oxygen sensor (HO2S) control is disabled
2. Three-way catalytic converter (TWC) diagnostics are disabled.

Possible Source

1. Incorrectly installed heated oxygen sensor (HO2S)
2. Damaged front heated oxygen sensor (HO2S).

Fault symptom[s]

1. Malfunction indicator lamp (MIL) lit.

Condition

The control module receives information from the heated oxygen sensor (HO2S) about the fuel / air mixture when idling at both the lower and upper part-load range. If the fuel / air mixture deviates from lambda=1, the short-term fuel trim will compensate for this by adjusting the injection time so that lambda=1 is achieved. When the short-term fuel trim makes an adjustment, the integrator median must be adjusted by the long-term trim. Diagnostic trouble code (DTC) ECM-260A is stored when the long-term trim must be adjusted to almost maximum in the upper part load area

Substitute Value

none

Possible Source

Upper limit

1. intake air leakage
2. exhaust system air leakage
3. low fuel pressure
4. defective heated oxygen sensor (HO2S)

Lower limit

1. intake air leakage
2. high fuel pressure
3. leaking injectors
4. defective mass air flow (MAF) sensor
5. contaminated engine oil
6. oil level too high
7. defective heated oxygen sensor (HO2S)

Fault symptom[s]

1. none

Condition

The control module receives information from the heated oxygen sensor (HO2S) about the fuel / air mixture when idling at both the lower and upper part-load range. If the fuel / air mixture deviates from lambda=1, the short-term fuel trim will compensate for this by adjusting the injection time so that lambda=1 is achieved. When the short-term fuel trim makes an adjustment, the integrator median must be adjusted by the long-term trim. Diagnostic trouble code (DTC) ECM-260A will be stored when the long-term trim must be adjusted to almost maximum in the upper part load area for bank 1 (cyl 1, 2 and 3).

Diagnostic trouble code (DTC) ECM-270A is stored for bank 2 (cyl 4, 5 and 6)

Substitute Value

none

Possible Source

Upper limit

1. intake air leakage
2. exhaust system air leakage
3. low fuel pressure
4. defective heated oxygen sensor (HO2S)

Lower limit

1. intake air leakage
2. high fuel pressure
3. leaking injectors
4. defective mass air flow (MAF) sensor
5. contaminated engine oil
6. oil level too high
7. defective heated oxygen sensor (HO2S)

Fault symptom[s]

1. none

see DIAGNOSTIC TROUBLE CODE (DTC) INFORMATION

See also:
• SIGNAL DESCRIPTION
• CHECKING WIRING AND TERMINALS