Page 1297 of 5267

3.(B22) VEHICLE SPEED SENSOR SIGNAL CIRCUIT OPEN BETWEEN CAB AND PCM
Turn the ignition off.
Measure the resistance of the (B22) Vehicle Speed Signal circuit
between the PCM harness connector and the CAB Module harness
connector.
Is the resistance above 5.0 ohms?
Ye s>>
Repair the open in the (B22) Vehicle Speed Signal circuit
between the CAB and PCM.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
No>>
Go To 4
4.(B22) VEHICLE SPEED SENSOR SIGNAL CIRCUIT SHORT TO GROUND
Measure the resistance between ground and the (B22) Vehicle Speed
Signal circuit at the PCM harness connector.
Istheresistancebelow100ohms?
Ye s>>
Repair the short to ground in the (B22) Vehicle Speed Sig-
nal circuit between the CAB and PCM.
Perform 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.
If there are no possible causes remaining, view repair.
Repair
Replace and program the Powertrain Control Module per Service Information.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Page 1306 of 5267

When Monitored:
Ignition on.
Set Condition:
When the PCM recognizes the Oil Pressure signal voltage lower than 0.3 of a volt.
Possible Causes
(F855) 5-VOLT SUPPLY CIRCUIT OPEN
(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
OIL PRESSURE SENSOR
(G6) OIL PRESSURE SIGNAL CIRCUIT SHORTED TO GROUND
(G6) OIL PRESSURE SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
1.OIL PRESSURE SENSOR VOLTAGE BELOW 0.1 VOLT
Start the engine.
With the scan tool in Sensors, read the Oil Pressure Sensor voltage.
Is the Oil Pressure Sensor voltage below 0.1 of a volt?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.(F855) 5-VOLT SUPPLY CIRCUIT
Turn the ignition off.
Disconnect the Oil Pressure Sensor harness connector.
Ignition on, engine not running.
Measure the voltage on the (F855) 5-volt Supply circuit in the Oil Pres-
sure Sensor harness connector.
Is the voltage between 4.5 to 5.2 volts?
Ye s>>
Go To 3
No>>
Go To 6
3.OIL PRESSURE SENSOR
WiththescantoolinSensors,readtheOilPressureSensorvoltagewiththeSensor harness connector still dis-
connected.
Is the voltage above 4.6 volts?
Ye s>>
Replace the Oil Pressure Sensor.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 4
Page 1307 of 5267
4.(G6) OIL PRESSURE SIGNAL CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Disconnect the C2 PCM harness connector.
Measure the resistance between (G6) Oil Pressure Signal circuit and
ground at the Sensor connector.
Istheresistancebelow100ohms?
Ye s>>
Repair the short to ground in the (G6) Oil Pressure Signal
circuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
No>>
Go To 5
5.(G6) OIL PRESSURE SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND CIRCUIT
Measure the resistance between the (G6) Oil Pressure Signal circuit
and the (K900) Sensor ground circuit at the Sensor connector.
Is the resistance below 5.0 ohms?
Ye s>>
Repair the short between the (K900) Sensor ground and the
(G6) Oil Pressure Signal circuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
No>>
Go To 8
Page 1308 of 5267

6.(F855) 5-VOLT SUPPLY CIRCUIT OPEN
Turn the ignition off.
Disconnect the C1 PCM harness connector.
Measure the resistance of the (F855) 5-volt Supply circuit from the Sen-
sor 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 (F855) 5-volt Supply circuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
7.(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the (F855) 5-volt Supply
circuit in the Oil Pressure Sensor harness connector.
Istheresistancebelow100ohms?
Ye s>>
Repair the short to ground in the (F855) 5-volt Supply cir-
cuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
No>>
Go To 8
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.
If there are no possible causes remaining, view repair.
Repair
Replace and program the Powertrain Control Module per Service Information.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Page 1310 of 5267

When Monitored:
With the ignition on and battery voltage above 10.4 volts.
Set Condition:
The oil pressure sensor signal at PCM goes above 4.9 volts. One Trip Fault.
Possible Causes
OIL PRESSURE SENSOR
(G6) OIL PRESSURE SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE
(G6) OIL PRESSURE SIGNAL CIRCUIT OPEN
(K900) SENSOR GROUND CIRCUIT OPEN
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
1.OIL PRESSURE SENSOR VOLTAGE ABOVE 4.8 VOLTS
Ignition on, engine not running.
With the scan tool in Sensors, read the Oil Pressure Sensor voltage.
Is the Oil Pressure Sensor voltage above 4.8 volts?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.OIL PRESSURE SENSOR
Turn the ignition off.
Disconnect the Oil Pressure Sensor harness connector.
Ignition on, engine not running.
Connect a jumper wire between the (G60) Oil Pressure Signal circuit and (K900) Sensor ground circuit at the Sen-
sor harness connector.
With the scan tool in Sensors, read the Oil Pressure Sensor voltage.
Is the voltage below 1.0 volt?
Ye s>>
Replace the Oil Pressure Sensor.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 3
NOTE: Remove the jumper wire before continuing.
3.(G6) OIL PRESSURE SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE
Turn the ignition off.
Disconnect the PCM harness connectors.
Ignition on, engine not running.
Using a 12-volt test light connected to ground, probe the (G6) Oil PressureSignal circuit.
Is the test light brightly illuminated?
Ye s>>
Repair the short to voltage in the (G6) Oil Pressure Signal circuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 4
Page 1311 of 5267

4.(G6) OIL PRESSURE SIGNAL CIRCUIT OPEN
Turn the ignition off.
Measure the resistance of the (G6) Oil Pressure Signal circuit from the OilPressure Sensor harness connector to
the PCM harness connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 5
No>>
Repair the open in the (G6) Oil Pressure Signal circuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE) Per-
form POWERTRAIN VERIFICATION TEST.
5.(K900) SENSOR GROUND CIRCUIT OPEN
Measure the resistance of the (K900) Sensor ground circuit from the Oil Pressure Sensor harness connector to the
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 POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
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.
If there are no possible causes remaining, view repair.
Repair
Replace and program the Powertrain Control Module per Service Information.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Page 1312 of 5267
P0601-PCM INTERNAL CONTROLLER FAILURE
For a complete wiring diagramRefer to Section 8W.
When Monitored:
With the ignition on.
Set Condition:
Internal checksum for software failed, does not match calculated value. One Trip Fault, Three Good Trips to
clear.
Possible Causes
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.PCM
NOTE: Diagnose any CMP or CKP Sensor faults before continuing. Check for intermittent loose CMP or CKP
connections.
The Powertrain Control Module is reporting internal errors, view repair to continue.
Repair
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Page 1325 of 5267
P1195-O2 SENSOR 1/1 SLOW DURING CATALYST MONITOR
For a complete wiring diagramRefer to Section 8W.