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Electronic Control System Gas Plus Engines – FAULT CODE 2221

Heated Oxygen Sensor Circuit – Failed In-Range Low

Overview

CODE REASON EFFECT
Fault Code: 2221
PID: S65
SPN: 724
FMI: 0/18
LAMP: Amber
SRT: 

Heated Oxygen Sensor Circuit – Failed In-Range Low. The measured air-to-fuel ratio is lower than the desired calculated air-to-fuel ratio.

Possible reduced performance. No closed loop operation.

Heated Oxygen Sensor Circuit

SMALL | MEDIUM | LARGE

Circuit Description

The electronic service tool (ECM) uses this sensor to determine the composition of the exhaust gas and then, to adjust fueling.

Component Location

The heated oxygen sensor is located in the exhaust outlet connection, after the turbocharger.

Shop Talk

The heated oxygen sensor measures the partial pressure of oxygen present in the exhaust gas. It measures this oxygen presence in lambda (L). The air-to-fuel ratio (stoichiometric) is 1L :16.5. The approximate lean-burn condition for the engine is 1.4.

The ECM will read an in-range low fault if the engine is running rich or the heated oxygen sensor or heated oxygen sensor circuit has failed. Excessive exhaust back pressure can cause this fault by creating a lower partial pressure of oxygen to form at the heated oxygen sensor. If the fuel control valve is stuck open the engine will not burn all the gas that is ingested causing it to run rich. If the heated oxygen sensor heater supply has shorted to ground or has a open circuit, then the sensor will read a lower than normal exhaust oxygen value.

Cautions and Warnings

 WARNING 

Do not touch the heated oxygen sensor until it has cooled. The heated oxygen sensor operates at high temperature and can cause personal injury.
 CAUTION 

Do not use any lubricant in the heated oxygen sensor connector. The sensor will not perform correctly with any grease in the connector.
 CAUTION 

To reduce the possibility of damaging a new ECM, all other active fault codes must be investigated prior to replacing the ECM.
 CAUTION 

To reduce the possibility of pin and harness damage, use the following test lead when taking a measurement:
Part Number 3822758 – male Deutsch/AMP/Metri-Pack test lead.

Troubleshooting Steps

STEPS SPECIFICATIONS
STEP 1. Check the fault codes.  
  STEP 1A. Check for fault codes. Fault Code 752 active?
  STEP 1B. Check for an inactive fault code. Fault Code 2219 inactive?
STEP 2. Check the engine harness and heated oxygen sensor.  
  STEP 2A. Inspect the engine harness and heated oxygen sensor connector pins. Dirty or damaged pins?
  STEP 2B. Check for pin short to ground in the engine harness. Less than 10 ohms?
  STEP 2C. Check for a pin to pin short circuit in the engine harness. Greater than 100k ohms?
  STEP 2D. Check the heated oxygen sensor heater supply voltage. Voltage Greater than 12 VDC?
  STEP 2E. Check for an inactive fault code. Fault Code 2219 inactive?
STEP 3. Check the fuel control valve .  
  STEP 3A. Check for a stuck open fuel control valve. Secondary fuel pressure drop within 50 seconds of key on?
STEP 4. Check the exhaust system  
  STEP 4A. Check for high exhaust back pressure. Exhaust back pressure within 61 to 127 mm-Hg [2.2 to 5.0 in-Hg]?
STEP 5. Check oil consumption.  
  STEP 5A. Check for excessive oil consumption. Excessive oil consumption?
  STEP 5B. Check for an inactive fault code. Fault Code 2219 inactive?
STEP 6. Clear the fault codes.  
  STEP 6A. Disable the fault code. Fault Code 2219 inactive?
  STEP 6B. Clear the inactive fault codes. All fault codes cleared?

Guided Step 1 – Check the fault codes.

Guided Step 1A – Check for fault codes.

Conditions

  • Turn keyswitch ON
  • Connect INSITE™ electronic service tool.

Action

  • Use INSITE™ electronic service tool to read the fault codes.

Fault Code 752 active?
YES NO
No Repair No Repair
Fault Code 752

Guided Step 1B – Check for an inactive fault code.

Conditions

  • Turn keyswitch ON
  • Connect INSITE™ electronic service tool.

Action

  • Use INSITE™ electronic service tool to read the fault codes.

Fault Code 2219 inactive?
YES NO
No Repair No Repair

Guided Step 2 – Check the engine harness and heated oxygen sensor.

Guided Step 2A – Inspect the engine harness and heated oxygen sensor connector pins.

Conditions

  • Turn keyswitch OFF
  • Disconnect engine harness connector 2 from the ECM.
  • Disconnect the heated oxygen sensor from the engine harness.

Action

  • Corroded pins
  • Bent or broken pins
  • Pushed back or expanded pins
  • Wire insulation damage
  • Moisture in or on the connector
  • Missing or damaged connector seals
  • Connector shell broken
  • Dirt or debris in or on the connector pins.

Refer to the circuit diagram or wiring diagram for connector pin identification.

For general inspection techniques, refer to Component Connector and Pin Inspection, Procedure 019-361.

Dirty or damaged pins?
YES NO

A defective connection has been detected in the ECM, engine harness or heated oxygen sensor connector.

Repair the damaged pins. Repair or replace the engine harness, or replace the sensor, whichever has the damaged pins.

  • Flush the dirt, debris, or moisture from the connector pins using electronic contact cleaner, Part Number 3824510.
  • Install the appropriate connector seal if it is damaged or missing.
  • Repair the harness. Refer to Procedure 019-204.
  • Replace the harness. Refer to Procedure 019-043.
  • Replace the Heated Oxygen Sensor. Refer to Procedure 019-100.
 No Repair

Guided Step 2B – Check for pin short to ground in the engine harness.

Conditions

  • Turn keyswitch OFF
  • Disconnect engine harness connector 2 from the ECM
  • Disconnect the heated oxygen sensor from the engine harness.

Action

  • Measure the resistance between the engine harness ECM connector 2 heated oxygen sensor adjustment current pin and engine block ground.
  • Measure the resistance between the engine harness ECM connector 2 heated oxygen sensor SIGNAL pin and engine block ground.

Refer to the circuit diagram or wiring diagram for connector pin identification.

For general resistance measurement techniques, refer to Resistance Measurements Using a Multimeter and Wiring Diagram, Procedure 019-360

Less than 10 ohms?
YES NO
No Repair

A pin short to ground in the adjustment current or signal circuit has been detected in the engine harness.

Repair the damaged pins. Repair or replace the engine harness, whichever has the damaged pins.

  • Flush the dirt, debris, or moisture from the connector pins using electronic contact cleaner, Part Number 3824510.
  • Install the appropriate connector seal if it is damaged or missing.
  • Repair the engine harness. Refer to Procedure 019-204.
  • Replace the engine harness. Refer to Procedure 019-043.

Guided Step 2C – Check for a pin to pin short circuit in the engine harness.

Conditions

  • Turn keyswitch OFF
  • Disconnect engine harness connector 1 and connector 2 from the ECM
  • Disconnect the heated oxygen sensor from the engine harness.

Action

  • Measure the resistance between the heated oxygen sensor adjustment current pin in the engine harness ECM connector 2 and all other pins in the ECM connector 2
  • Measure the resistance between the heated oxygen sensor adjustment current pin in the engine harness ECM connector 2 and all other pins in the ECM connector 1
  • Measure the resistance between the heated oxygen sensor SIGNAL pin in the engine harness ECM connector 2 and all other pins in the ECM connector 2.
  • Measure the resistance between the heated oxygen sensor SIGNAL pin in the engine harness ECM connector 2 and all other pins in the ECM connector 1.

Refer to the circuit diagram or wiring diagram for connector pin identification.

For general resistance measurement techniques, refer to Resistance Measurements Using a Multimeter and Wiring Diagram, Procedure 019-360

Greater than 100k ohms?
YES NO
No Repair

A pin to pin short circuit on the signal line or adjustment current line has been detected in the engine harness.

Repair the damaged pins. Repair or replace the engine harness, whichever has the damaged pins.

  • Flush the dirt, debris, or moisture from the connector pins using electronic contact cleaner, Part Number 3824510.
  • Install the appropriate connector seal if it is damaged or missing.
  • Repair the engine harness. Refer to Procedure 019-204.
  • Replace the engine harness. Refer to Procedure 019-043.

Guided Step 2D – Check the heated oxygen sensor heater supply voltage.

Conditions

  • Turn keyswitch OFF
  • Disconnect the heated oxygen sensor from the engine harness.

Action

  • Measure the voltage between the heated oxygen heater SUPPLY pin and the heated oxygen heater RETURN pin at the engine harness.

Refer to the circuit diagram or wiring diagram for connector pin identification.

Voltage greater than 12 VDC?
YES NO
No Repair

An open circuit or shorted to ground has been detected on the heated oxygen sensor supply line in the engine harness. An open circuit in the heated oxygen sensor return line can also be a possible fail mode.

Check for a blown, corroded or wet fuse in the heated oxygen heater supply line.

Repair the damaged pins. Repair or replace the engine harness, whichever has the damaged pins.

  • Flush the dirt, debris, or moisture from the connector pins using electronic contact cleaner, Part Number 3824510.
  • Install the appropriate connector seal if it is damaged or missing.
  • Repair the engine harness. Refer to Procedure 019-204.
  • Replace the engine harness. Refer to Procedure 019-043.

Guided Step 2E – Check for an inactive fault code.

Conditions

  • Connect all components
  • Turn keyswitch ON
  • Connect INSITE™ electronic service tool.

Action

  • Use INSITE™ electronic service tool to read the fault codes.

Fault Code 2219 inactive?
YES NO
No Repair No Repair

Guided Step 3 – Check the fuel control valve.

Guided Step 3A – Check for a stuck open fuel control valve.

Conditions

  • Turn keyswitch ON
  • Connect INSITE™ electronic service tool.

Action

  • Use INSITE™ electronic service tool to monitor the secondary fuel pressure while the keyswitch is on.

Note: If the fuel control valve is stuck open, raw fuel will be dumped into the engine and out the exhaust. This will cause the heated oxygen sensor to read a lower than actual air oxygen value.

Secondary fuel pressure drop within 50 seconds of key on?
YES NO

A defective fuel control valve has been detected.

Replace the fuel control valve. Refer to Procedure 019-102.

Use INSITE™ electronic service tool to reset the fuel tables.

 No Repair

Guided Step 4 – Check the exhaust systems.

Guided Step 4A – Check for high exhaust back pressure.

Conditions

  • Turn keyswitch OFF.

Action

  • Check the exhaust back pressure by installing a pressure gauge into the exhaust system just past the turbocharger outlet.
  • Refer to Procedure 011-009 in the Troubleshooting and Repair Manual C8.3G, C Gas Plus and L Gas Plus Engines, Bulletin 3666206 and Procedure 011-009 in the Troubleshooting and Repair Manual B5.9G, B5.9 LPG, B Gas Plus and B LPG Plus Engines, Bulletin 3666164.

Exhaust back pressure within 61 to 127 mm-Hg [2.2 to 5.0 in-Hg]?
YES NO
No Repair

Follow the troubleshooting steps in Procedure 011-009 in the Troubleshooting and Repair Manual C8.3G, C Gas Plus and L Gas Plus Engines, Bulletin 3666206 and Procedure 011-009 in the Troubleshooting and Repair Manual B5.9G, B5.9 LPG, B Gas Plus and B LPG Plus Engines, Bulletin 3666164.

Guided Step 5 – Check oil consumption.

Guided Step 5A – Check for excessive oil consumption.

Conditions

  • Turn keyswitch OFF.

Action

  • Refer to Lubricating Oil Consumption Excessive troubleshooting symptom tree in the Troubleshooting and Repair Manual C8.3G, C Gas Plus and L Gas Plus Engines, Bulletin 3666206 and in the Troubleshooting and Repair Manual B5.9G, B5.9 LPG, B Gas Plus and B LPG Plus Engines, Bulletin 3666164.

Excessive oil consumption?
YES NO
  • Refer to Lubricating Oil Consumption Excessive troubleshooting symptom tree in the Troubleshooting and Repair Manual C8.3G, C Gas Plus and L Gas Plus Engines, Bulletin 3666206 and in the Troubleshooting and Repair Manual B5.9G, B5.9 LPG, B Gas Plus and B LPG Plus Engines, Bulletin 3666164.
 No Repair

Guided Step 5B – Check for an inactive fault code.

Conditions

  • Connect all components
  • Turn keyswitch ON
  • Connect INSITE™ electronic service tool.

Action

  • Use INSITE™ electronic service tool to read the fault codes.

Fault Code 2219 inactive?
YES NO
No Repair

Replace the heated oxygen sensor. Refer to Procedure 019-100.

Use INSITE™ electronic service tool to reset.

Guided Step 6 – Clear the fault codes.

Guided Step 6A – Disable the fault code.

Conditions

  • Connect all components
  • Turn keyswitch ON
  • Connect INSITE™ electronic service tool.

Action

  • Start the engine and let it idle for one minute.
  • Use INSITE™ electronic service tool to verify that the fault code is inactive.

Fault Code 2219 inactive?
YES NO
No Repair No Repair

Guided Step 5B – Clear the inactive fault codes.

Conditions

  • Connect all components
  • Turn keyswitch ON
  • Connect INSITE™ electronic service tool.

Action

  • Use INSITE™ electronic service tool to erase the inactive fault codes.

All fault codes cleared?
YES NO
No Repair No Repair
Repair complete
Appropriate troubleshooting charts
Last Modified:  14-Sep-2004
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