2006 DODGE RAM SRT-10 relay

Theory of Operation
This diagnostic provides a continuous check of the O2 heater circuit during operation. The heater circuit is momen-
tarily disabled to allow a resistance measurement to be taken to infer heater temperature. The current delivery to
the heater is duty cycled to maintain a specific target temperature. The error from the target temperature is contin-
uously monitored to assess heater performance.
When Monitored:
With battery voltage greater than 10.5 volts, at a cold start, ECT less than147°F, battery temperature sensor
equal to or less than 27°F, and engine at idle for at least 12 seconds.
Set Condition:
O2 sensor voltage greater than 3 volts for 60 to 240 seconds.
Possible Causes
(K344) O2 SENSOR HEATER RELAY OUTPUT CIRCUIT OPEN
(K344) O2 SENSOR HEATER RELAY OUTPUT CIRCUIT SHORTED TO GROUND
(K127) O2 HEATER RELAY CONTROL CIRCUIT OPEN
(K127) O2 HEATER RELAY CONTROL CIRCUIT SHORTED TO GROUND
(Z1) HEATER GROUND CIRCUIT OPEN
O2 SENSOR
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.O2 SENSOR HEATER OPERATION
Turn the ignition off.
NOTE: Wait a minimum of 8 minutes to allow the O2 Sensor to cool down before continuing the test.
Ignition on, engine not running.
With the scan tool, actuate the O2 Heater Test.
With the scan tool, monitor O2 Sensor voltage for at least 2 minutes.
Does the voltage stabilize between 0.1 and 0.3 of a volt during the Heater test?
Ye s>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 2
2.O2 SENSOR HEATER ELEMENT
Turn the ignition off.
NOTE: Allow the O2 Sensor to cool to room temperature.
Disconnect the O2 Sensor harness connector.
Measure the resistance across the O2 Sensor Heater element component side.
NOTE: The resistance value will increase with warmer temperatures.
Is the resistance between 4.0 and 5.0 ohms at 70° F (21.1°C)?
Ye s>>
Go To 3
No>>
Replace the O2 Sensor.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

3.(K344) O2 SENSOR HEATER RELAY OUTPUT CIRCUIT
Ignition on, engine not running and the O2 Sensor still disconnected.
With the scan tool, actuate the O2 Heater Test.
Using a 12-volt test light connected to ground, probe the (K344) O2
Heater Relay Output circuit at the O2 Sensor harness connector.
Does the light illuminate brightly?
Ye s>>
Go To 4
No>>
Repair the open or short to ground in the (K344) O2 Heater
Relay Output circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
4.(K127) O2 HEATER RELAY CONTROL CIRCUIT OPEN
Turn the ignition off.
Disconnect the PCM harness connectors.
RemovetheO2HeaterRelay.
Measure the resistance of the (K127) O2 Heater Relay Control circuit from the O2 Heater Relay to the PCM har-
ness connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 5
No>>
Repair the excessive resistance in the (K127) O2 Heater Relay Control circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
5.(K127) O2 HEATER RELAY CONTROL CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the (K127) O2 Heater
Relay Control circuit at the PCM harness connector.
Istheresistancebelow100ohms?
Ye s>>
Repair the short to ground in the (K127) O2 Heater Relay
Control circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 6

When Monitored:
With battery voltage greater than 10.4 volts, engine running for more than4 minutes and coolant temperature
above 180°F.
Set Condition:
The oxygen sensor voltage is above 1.5 volts.
Possible Causes
(K43) O2 2/1 SIGNAL CIRCUIT SHORTED TO VOLTAGE
(K199) O2 SENSOR 2/1 HEATER CONTROL CIRCUIT OPEN
(K43) O2 2/1 SIGNAL CIRCUIT OPEN
(K900) SENSOR GROUND CIRCUIT OPEN
(K343) ASD RELAY OUTPUT CIRCUIT OPEN
(K43) O2 2/1 SIGNAL CIRCUIT SHORTED TO THE (K343) ASD RELAY OUTPUT CIRCUIT
O2 SENSOR
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.O2 SENSOR ABOVE 1.5 VOLTS
Ignition on, engine not running.
With the scan tool, read DTCs and record the related Freeze Frame data.
Start the engine.
Allow the engine to idle for 4 to 5 minutes.
With the scan tool, read the O2 Sensor voltage.
Is the voltage above 1.5 volts?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.(K43) O2 2/1 SIGNAL CIRCUIT SHORTED TO VOLTAGE
Turn the ignition off.
Disconnect the C1 PCM harness connector.
Ignition on, engine not running.
Using a 12-volt test light connected to ground, probe the (K43) O2 Sen-
sor 2/1 Signal circuit at the 2/1 O2 Sensor harness connector.
Does the test light illuminate brightly?
Ye s>>
Repair the short to voltage in the (K43) O2 Sensor 2/1 Sig-
nal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 3

3.(K43) O2 SENSOR 2/1 SIGNAL CIRCUIT OPEN
Turn the ignition off.
Measure the resistance of the (K43) O2 Sensor 2/1 Signal circuit from
the O2 Sensor harness connector to the C1 PCM harness connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 4
No>>
Repair the open in the (K43) O2 Sensor 2/1 Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
4.(K43) O2 2/1 SENSOR SIGNAL CIRCUIT SHORTED TO THE (K343) ASD RELAY OUTPUT CIRCUIT
Measure the resistance between the (K43) O2 Sensor 2/1 Signal circuit
and the (K343) ASD Relay Output circuit at the O2 Sensor harness con-
nector.
Istheresistancebelow100ohms?
Ye s>>
Repair the short between the (K43) O2 Sensor 2/1 Signal
circuit and the (K343) ASD Relay Output circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 5

5.(K900) SENSOR GROUND CIRCUIT OPEN
Measure the resistance of the (K900) Sensor ground circuit from the O2
Sensor harness connector to the C1 PCM harness connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 6
No>>
Repair the open in the (K900) Sensor ground circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
6.(K343) ASD RELAY OUTPUT CIRCUIT OPEN
Connect the PCM harness connectors.
Ignition on, engine not running.
With the scan tool actuate the O2 Heater Test.
Using a 12-volt test light connected to ground, probe the (K343) ASD
Relay Output circuit.
Does the test light illuminate brightly?
Ye s>>
Go To 7
No>>
Repair the open in the (K343)ASD Relay Output circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)

When Monitored:
With battery voltage greater than 9 volts, at a cold start, ECT less than 147°F, battery temperature sensor
equal to or less than 27°F, and engine at idle for at least 12 seconds.
Set Condition:
O2 sensor voltage greater than 3 volts for 30 to 90 seconds.
Possible Causes
(K199) O2 2/1 HEATER CONTROL CIRCUIT OPEN
(K199) O2 2/1 HEATER CONTROL CIRCUIT SHORTED TO GROUND
(K343) O2 FUSED ASD RELAY OUTPUT CIRCUIT OPEN
(K343) O2 FUSED ASD RELAY OUTPUT CIRCUIT SHORTED TO GROUND
O2 SENSOR
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.O2 SENSOR HEATER OPERATION
Turn the ignition off.
NOTE: Wait a minimum of 8 minutes to allow the O2 Sensor to cool down before continuing the test. Allow
the O2 Sensor voltage to stabilize between 4.6 and 5.0 volts.
Ignition on, engine not running.
With a scan tool, actuate the O2 Heater Test.
With the scan tool, monitor 2/1 O2 Sensor voltage for at least 2 minutes.
Does the voltage stay above 4.5 volts?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Symptom. (Refer to 9 - ENGINE - DIAGNOSIS AND TEST-
ING)
2.O2 SENSOR HEATER ELEMENT
Turn the ignition off.
NOTE: Allow the O2 sensor to cool down to room temperature.
Disconnect the O2 Sensor harness connector.
Measure the resistance of the O2 Heater Element across the 2/1 O2 Sensor connector between the (K199) O2
Heater Control terminal and the (K343) Fused ASD relay output terminal.
NOTE: O2 Heater Element resistance values should be measured at 70°F (21.1°C). The resistance value will
vary with different temperature values.
Is the resistance of the O2 Sensor Heater Element between 3.3 and 4.1 ohms?
Ye s>>
Go To 3
No>>
Replace the O2 Sensor.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

3.(K199) O2 2/1 HEATER CONTROL CIRCUIT OPEN
Disconnect the C3 PCM harness connector.
Measure the resistance of the (K199) O2 2/1 Heater Control circuit from
the O2 harness connector to the PCM harness connector.
Is the resistance below 5 ohmS?
Ye s>>
Go To 4
No>>
Repair the excessive resistance in the (K199) O2 2/1
Heater Control circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
4.(K343) O2 2/1 FUSED ASD RELAY OUTPUT CIRCUIT OPEN
Measure the resistance of the (K343) O2 2/1 Fused ASD Relay Output circuit,from the relay terminal to the O2
Sensor harness connector.
Is the resistance below 5 ohms?
Ye s>>
Go To 5
No>>
Repair the excessive resistance in the (K343) O2 2/1 Fused ASD relay outputcircuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
5.(K343) O2 2/1 FUSED ASD RELAY OUTPUT CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the (K343) O2 2/1 Fused
ASD Relay Output circuit in the O2 Sensor harness connector.
Is the resistance below 5 ohms?
Ye s>>
Repair the short to ground in the (K343) O2 2/1 Fused ASD
Relay Output circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 6

5.(K243) O2 SENSOR 2/2 SIGNAL CIRCUIT SHORTED TO THE (K344) O2 HEATER RELAY OUTPUT CIRCU
IT
Measure the resistance between the (K243) O2 Sensor 2/2 Signal cir-
cuit and the (K344) O2 Heater Relay Output circuit at the O2 Sensor
harness connector.
Istheresistancebelow100ohms?
Ye s>>
Repair the short between the (K243) O2 Sensor 2/2 Signal
circuit and the (K344) O2 Heater Relay Output circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 6
6.(K900) SENSOR GROUND CIRCUIT OPEN
Measure the resistance of the (K900) Sensor ground circuit from the 2/2
O2 Sensor harness connector to the PCM harness connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 7
No>>
Repair the open in the (K900) Sensor ground circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)