Page 1024 of 5267

3.(K43) O2 SENSOR 2/1 SIGNAL CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Disconnect the C1 PCM harness connector.
Measure the resistance between ground and the (K43) O2 Sensor 2/1
Signal circuit at the 2/1 O2 Sensor harness connector.
Istheresistancebelow100ohms?
Ye s>>
Repair the short to ground in the (K43) O2 Sensor 2/1Sig-
nal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 4
4.(K43) O2 SENSOR 2/1 SIGNAL CIRCUIT SHORTED TO (K900) SENSOR GROUND CIRCUIT
Measure the resistance between the (K43) O2 Sensor 2/1 Signal circuit
and the (K900) Sensor ground circuit at the 2/1 O2 Sensor harness
connector.
Istheresistancebelow100ohms?
Ye s>>
Repair the short between the (K900) Sensor ground circuit
and the (K43) O2 Sensor 2/1 Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 5
5.PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.
Were there any problems found?
Ye s>>
Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Page 1029 of 5267

7.(K199) O2 SENSOR 2/1 HEATER CONTROL CIRCUIT OPEN
Turn the ignition off.
Disconnect the C3 PCM harness connector.
Measure the resistance of the (K199) O2 Sensor 2/1 Heater Control cir-
cuit from the O2 Sensor harness connector to the PCM harness con-
nector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 8
No>>
Repair the open in the (K199) O2 Sensor 2/1 Heater Con-
trol Circuit (PWM) circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
8.PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.
Were there any problems found?
Ye s>>
Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Page 1036 of 5267
6.PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.
Were there any problems found?
Ye s>>
Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Page 1040 of 5267
6.PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.
Were there any problems found?
Ye s>>
Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Page 1045 of 5267

7.(K344) O2 SENSOR HEATER RELAY OUTPUT CIRCUIT OPEN
Connect the PCM harness connectors.
Ignition on, engine not running.
With the scan tool actuate the O2 Heater Test.
Measure the voltage on the (K344) O2 Sensor Heater Relay Output cir-
cuit.
Is the voltage above 11.0 volts?
No>>
Repair the open in the (K344) O2 Sensor Heater Relay Out-
put circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
Ye s>>
Go To 8
8.(Z1) O2 SENSOR HEATER GROUND CIRCUIT OPEN
Turn the ignition off.
Disconnect the PCM harness connectors.
Measure the resistance between ground and the (Z1) O2 Sensor Heater
ground circuit from the 2/2 O2 Sensor harness connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 9
No>>
Repair the open in the (Z1) O2 Sensor Heater ground cir-
cuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
9.PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.
Were there any problems found?
Ye s>>
Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Page 1052 of 5267
6.(Z1) HEATER GROUND CIRCUIT OPEN
Using a 12-volt test light connected to 12-volts, probe the (Z1) O2
Heater Ground circuit at the O2 Sensor harness connector.
Does the test light illuminate brightly?
Ye s>>
Go To 7
No>>
Repair the open in the (Z1) O2 Sensor Heater ground cir-
cuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
7.PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.
Were there any problems found?
Ye s>>
Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Page 1059 of 5267
15.PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.
If there are no possible causes remaining, view repair.
Repair
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Page 1065 of 5267

12.(K41) O2 SENSOR 1/1 SIGNAL CIRCUIT OPEN
Turn the ignition off.
Disconnect the PCM harness connectors.
Measure the resistance of the (K41) O2 Sensor 1/1 Signal circuit from
the PCM harness connector to the O2 Sensor harness connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 13
No>>
Repair the open in the (K41) O2 Sensor 1/1 Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
13.(K41) O2 SENSOR 1/1 SIGNAL CIRCUIT SHORTED TO VOLTAGE
Ignition on, engine not running.
Leave the O2 Sensor and PCM harness connectors disconnected.
Measure the voltage on the (K41) O2 Sensor 1/1 Signal circuit at the
1/1 O2 Sensor harness connector.
Is the voltage above 5.2 volts?
Ye s>>
Repair the short to voltage in the O2 Sensor Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 14
NOTE: Turn the ignition off before continuing.
14.PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.
If there are no possible causes remaining, view repair.
Repair
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)