P1618
P1618-SENSOR REFERENCE VOLTAGE 1 CIRCUIT ERRATIC
For a complete wiring diagram, refer to the Wiring Information.
- When Monitored:
With the ignition on.
- Set Condition:
The Powertrain Control Module (PCM) detects an excessive voltage variation on the 5-Volt supply circuit.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.
1. DTC IS ACTIVE
1. Start the engine and allow it to reach normal operating temperature.
WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury.
2. With the scan tool, select View DTCs.
Is the status Active for this DTC?
Yes
- Go To 2
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test.
2. (F855) 5-VOLT SUPPLY CIRCUIT VOLTAGE
1. Turn the ignition off.
2. Disconnect the APP Sensor harness connector.
3. Turn the ignition on.
4. Measure the voltage of the (F855) 5-Volt Supply circuit.
Select the appropriate response from the list below:
Voltage more than 5.2 Volts
- Repair the (F855) 5 Volt Supply circuit for a short to voltage.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
Voltage between 4.8 and 5.2 Volts
- Go To 3
Voltage below 4.8 Volts
- Go To 4
3. ACCELERATOR PEDAL POSITION SENSOR
1. Turn the ignition off.
2. Reconnect the APP Sensor harness connector.
3. Disconnect the Camshaft 1/2 Position Sensor harness connector.
4. Turn the ignition on.
5. Measure the voltage of the (F855) 5 Volt Supply circuit in the Camshaft 1/2 Position Sensor harness connector.
Is the voltage below 4.8 Volts?
Yes
- Replace the Accelerator Pedal Position Sensor.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Go To 9
4. CAMSHAFT 1/2 POSITION SENSOR
1. Turn the ignition off.
2. Disconnect the Camshaft 1/2 Position Sensor harness connector.
3. Turn the ignition on.
4. Measure the voltage of the (F855) 5 Volt Supply circuit in the APP Sensor harness connector.
Is the voltage above 4.8 Volts?
Yes
- Replace the Camshaft 1/2 Position Sensor.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Go To 5
5. THROTTLE POSITION SENSOR
1. Turn the ignition off.
2. Disconnect the Throttle Body harness connector.
3. Turn the ignition on.
4. Measure the voltage of the (F855) 5 Volt Supply circuit.
Is the voltage above 4.8 Volts?
Yes
- Replace the Throttle Body.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Go To 6
6. CRANKSHAFT POSITION SENSOR
1. Turn the ignition off.
2. Disconnect the Crankshaft Position Sensor harness connector.
3. Turn the ignition on.
4. Measure the voltage of the (F855) 5-Volt Supply circuit.
Is the voltage above 4.8 Volts?
Yes
- Replace the Crankshaft Position Sensor.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Go To 7
7. 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
NOTE: All sensors connected to the (F855) 5-Volt supply circuit and the (F855) 5 volt supply circuit must be disconnected.
1. Turn the ignition off.
2. Disconnect the PCM harness connectors.
3. Measure the resistance between ground and the (F855) 5-Volt Supply circuit.
4. Measure the resistance between ground and the (K852) 5-Volt Supply circuit.
Is the resistance above 1000 Ohms for both circuits?
Yes
- Go To 8
No
- Repair the 5-Volt Supply circuit for a short to ground.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
8. 5-VOLT SUPPLY CIRCUIT OPEN OR HIGH RESISTANCE
NOTE: All sensors connected to the (F855) 5-Volt supply circuit and the (K852) 5-Volt supply circuit must be disconnected.
1. Turn the ignition off.
2. Measure the resistance of the (F855) 5-Volt Supply circuit between the Camshaft 1/2 Position Sensor harness connector and the PCM harness connector.
3. Measure the resistance of the (F855) 5-Volt Supply circuit between the Crankshaft Position Sensor harness connector and the PCM harness connector.
4. Measure the resistance of the (F855) 5-Volt Supply circuit between the Throttle Body harness connector and the PCM harness connector.
5. Measure the resistance of the (K852) 5-Volt Supply circuit between the Accelerator Pedal Position Sensor harness connector and the PCM harness connector.
6. If the vehicle is equipped with a manual transmission, measure the resistance of the (K856) 5-Volt Supply circuit between the Vehicle Speed Sensor harness connector and the PCM harness connector.
Is the resistance below 5.0 Ohms for all of the circuits?
Yes
- Go To 9
No
- Repair the 5-Volt Supply circuit for an open circuit or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
9. POWERTRAIN CONTROL MODULE (PCM)
1. Inspect the (F855) 5-Volt Supply circuit between the Camshaft 1/2 Position Sensor harness connector and the PCM harness connector.
2. Inspect the (F855) 5-Volt Supply circuit between the Crankshaft Position Sensor harness connector and the PCM harness connector.
3. Inspect the (F855) 5-Volt Supply circuit between the Throttle Body harness connector and the PCM harness connector.
4. Inspect the (K852) 5-Volt Supply circuit between the Accelerator Pedal Position Sensor harness connector and the PCM harness connector.
5. If the vehicle is equipped with a manual transmission, inspect the (F856) 5-Volt Supply circuit between the Vehicle Speed Sensor harness connector and the PCM harness connector.
6. Inspect all PCM power and ground circuits.
7. Look for any chafed, pierced, pinched, or partially broken wires.
8. Look for broken, bent, pushed out or corroded terminals.
9. Perform any Technical Service Bulletins that may apply.
Were any problems found?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Replace and program the Powertrain Control Module (PCM). Powertrain Control Module - Removal.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.