P2077

P2077-INTAKE MANIFOLD TUNING VALVE POSITION SENSOR CIRCUIT LOW

For a complete wiring diagram Consult Diagrams/Electrical

- When Monitored:
With the ignition on and battery voltage greater than 10.4 volts.

- Set Condition:
The PCM detects that the PWM signal from the Manifold Tune Valve Position sensor is below the minimum acceptable value.

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.Initial Inspection and Diagnostic Overview

Diagnostic Test

1. MTV PWM FEEDBACK
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 can result in personal injury or death.

NOTE: Diagnose and repair any system voltage or sensor supply voltage DTCs before continuing with this test.

With the scan tool, read the MTV PWM Feedback.
Is the MTV PWM Feedback less than 3%?

Yes

- Go to 2

No

- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure.Checking For An Intermittent DTC

2. MANIFOLD TUNE VALVE ASSEMBLY
Turn the ignition off.
Disconnect the Manifold Tune Valve Assembly connector.
Turn the ignition on.
With the scan tool, read the MTV PWM Feedback.

NOTE: The MTV PWM Feedback should be greater than 97% with the connector disconnected.

Is the MTV PWM Feedback greater than 97%?

Yes

- Replace the Manifold Tune Valve Assembly.
- Perform the PCM Verification Test.Powertrain Verification Test

No

- Go to 3

3. (F855) 5 VOLT SUPPLY CIRCUIT VOLTAGE

Turn the ignition on.
Measure the voltage of the (F855) 5 Volt Supply circuit in the Manifold Tune Valve Assembly harness connector.
Is the voltage above 4.5 volts?

Yes

- Go to 7

No

- Go to 4

4. (F855) 5 VOLT SUPPLY CIRCUIT SHORTED TO GROUND

Turn the ignition on.
Disconnect the Powertrain Control Module (PCM) connector.
Measure the resistance between ground and the (F855) 5 Volt Supply circuit in the Manifold Tune Valve Assembly harness connector.
Is the resistance above 100 ohms?

Yes

- Go to 5

No

- Repair the (F855) 5 Volt Supply circuit for a short to ground.
- Perform the PCM Verification Test.Powertrain Verification Test

5. (F855) 5 VOLT SUPPLY CIRCUIT SHORTED TO (K900) SENSOR GROUND CIRCUIT

Measure the resistance between the (F855) 5 Volt Supply circuit and the (K900) Sensor Ground circuit in the Manifold Tune Valve Assembly harness connector.
Is the resistance above 100 ohms?

Yes

- Go to 6

No

- Repair the (F855) 5 Volt Supply circuit for a short to the (K900) Sensor Ground circuit.
- Perform the PCM Verification Test.Powertrain Verification Test

6. (F855) 5 VOLT SUPPLY CIRCUIT OPEN OR HIGH RESISTANCE

Turn the ignition off.
Disconnect the Powertrain Control Module (PCM) connector.
Measure the resistance between ground and the (K234) MTV Signal circuit in the Manifold Tune Valve Assembly harness connector.
Is the resistance above 100 ohms?

Yes

- Go to 8

No

- Repair the (K234) MTV Signal circuit for a short to ground.
- Perform the PCM Verification Test.Powertrain Verification Test

8. (K234) MTV SIGNAL CIRCUIT SHORTED TO (K900) SENSOR GROUND CIRCUIT

Measure the resistance between the (K234) MTV Signal circuit and the (K900) Sensor Ground circuit in the Manifold Tune Valve Assembly harness connector.
Is the resistance above 100 ohms?

Yes

- Go to 9

No

- Repair the (K234) MTV Signal circuit for a short to the (K900) Sensor Ground circuit.
- Perform the PCM Verification Test.Powertrain Verification Test

9. (K234) MTV SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE

CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals, resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.

Measure the resistance of the (K234) MTV Signal circuit between the Manifold Tune Valve Assembly harness connector and the appropriate terminal of special tool #8815.
Is the resistance below 5.0 ohms?

Yes

- Go to 10

No

- Repair the (K234) MTV Signal circuit for an open circuit or high resistance.
- Perform the PCM Verification Test.Powertrain Verification Test

10. (K900) SENSOR GROUND CIRCUIT OPEN OR HIGH RESISTANCE

CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals, resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.

Measure the resistance of the (K900) Sensor Ground circuit between the Manifold Tune Valve Assembly harness connector and the appropriate terminal of special tool #8815.
Is the resistance below 5.0 ohms?

Yes

- Go to 11

No

- Repair the (K900) Sensor Ground circuit for an open circuit or high resistance.
- Perform the PCM Verification Test.Powertrain Verification Test

11. POWERTRAIN CONTROL MODULE (PCM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Manifold Tune Valve Assembly and the Powertrain Control Module (PCM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals.
Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
Look for the data to change or for the DTC to reset during the wiggle test.
Search for any Technical Service Bulletins that may apply.
Were any problems found?

Yes

- Repair as necessary.
- Perform the PCM Verification Test.Powertrain Verification Test

No

- Replace and program the Powertrain Control Module (PCM).
- Perform the PCM Verification Test.Powertrain Verification Test