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Electronic Control System Gas Plus Engines – FAULT CODE 2188

Heated Oxygen Sensor Circuit – Heater Shorted High

Overview

CODE REASON EFFECT
Fault Code: 2188
PID: S151
SPN: 611
FMI: 4
LAMP: Amber
SRT: 

Heated Oxygen Sensor Circuit – Heater Shorted High. Open circuit detected on the heater return pin at the ECM or no heater supply voltage.

Possible reduced performance. No closed loop operation.

Heated Oxygen Sensor Circuit

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Circuit Description

The electronic control module (ECM) uses this sensor to determine the composition of the exhaust gas and then, to adjust fueling when operating in closed loop.

Component Location

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

Shop Talk

The oxygen sensor is used to correct the fuel composition that is used by the engine. The sensor only affects the closed-loop operation of the engine.

If the fault code remains active after all troubleshooting steps have been followed, the sensor can possibly have a voltage supply issue. Remove pin 26 from the OEM side of the 31-pin connector and connect a 12-VDC supply from the vehicle battery to the heated oxygen sensor heater positive pin 26. If the fault code goes inactive, there is a voltage drop in the OEM supply circuit to pin 26.

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 the fault codes. Fault Code 2188 active?
STEP 2. Check the heated oxygen sensor.  
  STEP 2A. Inspect the engine harness and sensor connector pins. Dirty or damaged pins?
  STEP 2B. Check the heater supply voltage. Supply voltage is greater than 12 VDC?
  STEP 2C. Check the heated oxygen sensor heater. Resistance is between 2 ohms and 10 ohms?
  STEP 2D. Check the fault codes and verify sensor condition. Fault Code 2188 active?
STEP 3. Check the engine harness.  
  STEP 3A. Inspect the engine harness and ECM connector pins. Dirty or damaged pins?
  STEP 3B. Check for an open circuit. Less than 10 ohms?
  STEP 3C. Check for a short circuit to ground. Greater than 100k ohms?
STEP 4. Clear the fault codes.  
  STEP 4A. Disable the fault code. Fault Code 2188 inactive?
  STEP 4B. Clear the inactive fault codes. All fault codes cleared?

Guided Step 1 – Check the fault codes.

Guided Step 1A – Check the fault codes.

Conditions

  • 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 read the fault codes.

Fault Code 2188 active?
YES NO
No Repair No Repair

Guided Step 2 – Check the heated oxygen sensor.

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

Conditions

  • Turn keyswitch OFF
  • 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 sensor or harness 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 019-203.
  • Replace the harness. Refer to Procedure 019-043.
  • Replace the Heated Oxygen Sensor. Refer to Procedure 019-100.
 No Repair

Guided Step 2B – Check the heater supply voltage.

Conditions

  • Turn keyswitch ON
  • Engine not running
  • Disconnect the heated oxygen sensor from the engine harness.

Action

  • Measure the heated oxygen sensor heater SUPPLY voltage from the engine harness connector to chassis ground.

Note: See Shop Talk.

Supply voltage is greater than 12 VDC?
YES NO
No Repair

There is an open circuit or short circuit to ground in the heated oxygen sensor SUPPLY line. Check the OEM voltage SUPPLY and heated oxygen sensor fuse. Repair or replace the heated oxygen heater line.

Refer to the OEM troubleshooting and repair manual and the note in Shop Talk.

Guided Step 2C – Check the heated oxygen sensor heater.

Conditions

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

Action

  • Measure the resistance between the heated oxygen sensor heater positive and the heated oxygen sensor heater negative at the heated oxygen connector.

Resistance is between 2 ohms and 10 ohms?
YES NO
No Repair

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

Guided Step 2D – Check the fault codes and verify sensor condition.

Conditions

  • Turn keyswitch OFF
  • Connect the heated oxygen sensor to the engine harness
  • Turn keyswitch ON
  • Connect INSITE™ electronic service tool.

Action

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

Fault Code 2188 active?
YES NO
No Repair No Repair

Guided Step 3 – Check the engine harness.

Guided Step 3A – Inspect the engine harness and ECM connector pins.

Conditions

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

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 connector or engine harness connector.

Repair the damaged pins. Repair or replace the engine harness, or replace the ECM, 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 019-208 or 019-204.
  • Replace the engine harness. Refer to Procedure 019-043.
  • Replace the ECM. Call for pre-authorization. Refer to Procedure 019-031.
 No Repair

Guided Step 3B – Check for an open circuit.

Conditions

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

Action

  • Measure the resistance between the heated oxygen sensor heater negative pin on the heated oxygen sensor engine harness connector to the heated oxygen sensor heater negative pin on 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

SMALL | MEDIUM | LARGE

Less than 10 ohms?
YES NO
No Repair

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 3C – Check for a short circuit to ground.

Conditions

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

Action

  • Measure the resistance from the heated oxygen heater negative pin in engine harness connector 1 to ground.
SMALL | MEDIUM | LARGE

Greater than 100k ohms?
YES NO
No Repair

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 4 – Clear the fault codes.

Guided Step 4A – 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 Fault Code 2188 is inactive.

Fault Code 2188 inactive?
YES NO
No Repair

Troubleshooting procedures need to be repeated from the beginning.

Guided Step 4B – Clear the inactive fault codes.

Conditions

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

Action

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

All fault codes cleared?
YES NO
No Repair

Troubleshoot any remaining active fault codes.
Repair complete
Appropriate troubleshooting steps
Last Modified:  28-Sep-2004
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