P2074

P2074-MAP/TPS CORRELATION - HIGH AIRFLOW/VACUUM LEAK DETECTED

For a complete wiring diagram Refer to the Wiring Information.

- When Monitored:
During all drive modes

- Set Condition:
With engine vacuum below 1.5" Hg, engine RPM greater than 2000 RPM, and a closed throttle. One Trip Fault. Three good trips to turn off the MIL.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.Pre-Diagnostic Troubleshooting Procedure.

1. ACTIVE DTC

NOTE: Diagnose and repair any TP Sensor or MAP Sensor DTCs before continuing.

NOTE: Diagnose and repair any VSS or 5 Volt supply circuit DTCs before continuing.

NOTE: The throttle plate and linkage should be free from binding and carbon build up.

NOTE: Make sure the throttle plate is at the idle position.

1. Ignition on, engine not running.
2. With a scan tool, select View DTCs.

Is the status Active for this DTC?

Yes

- Go to 2

No

- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure.Checking for an Intermittent DTC

2. VACUUM LEAK

NOTE: This code is enabled on engines equipped with a plastic intake manifold to limit engine operation if a large vacuum leak should occur.

NOTE: A large vacuum leak is the most probable cause of this DTC.

1. Inspect the intake manifold, power brake booster, and PCV system for any vacuum leaks.
2. Inspect the throttle plate. If the throttle blade is bent or will not close, the throttle body may need to be replaced.
3. Inspect the MAP Sensor and Throttle Body for proper installation.
4. Inspect the engine for any mechanical conditions that can cause low engine vacuum.

Were any problems found?

Yes

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

No

- Go to 3

3. MAP SENSOR OPERATION
1. Start the engine.
2. With a scan tool, monitor the MAP Sensor voltage.
3. Snap the throttle.

Does the MAP Sensor voltage vary from below 2.0 volts at idle to above 3.5 volts at wide open throttle?

Yes

- Go to 5

No

- Go to 4

4. MAP SENSOR
1. Turn the ignition off.
2. Disconnect the MAP Sensor harness connector.
3. Disconnect the PCM harness connector.
4. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the MAP Sensor and the Powertrain Control Module (PCM).
5. Look for any chafed, pierced, pinched, or partially broken wires.
6. Look for broken, bent, pushed out or corroded terminals.
7. Check each of the MAP Sensor circuits for high resistance or a shorted condition.

Were any problems found?

Yes

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

No

- Replace the MAP Sensor.
- Perform the PCM Verification TestPCM Verification Test.

5. THROTTLE FOLLOWER TEST
1. Ignition on, engine not running.
2. With a scan tool, perform the Throttle Follower Test and monitor the TP Sensor 1 and TP Sensor 2 voltages.
3. Slowly press the throttle pedal down.
4. The voltage for TP Sensor 1 should start at approximately 0.5 volts and increase to approximately 3.3 volts.
5. The voltage for TP Sensor 2 should start at approximately 4.4 volts and decrease to approximately 1.7 volts.

Is the voltage within the range specified for each sensor?

Yes

- Go to 7

No

- Go to 6

6. THROTTLE BODY
1. Turn the ignition off.
2. Disconnect the Throttle Body harness connector.
3. Disconnect the PCM harness connector.
4. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Throttle Body and the Powertrain Control Module (PCM).
5. Look for any chafed, pierced, pinched, or partially broken wires.
6. Look for broken, bent, pushed out or corroded terminals.
7. Check each of the Throttle Body circuits for high resistance or a shorted condition.

Were any problems found?

Yes

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

No

- Replace the Throttle Body.
- Perform the PCM Verification TestPCM Verification Test.

7. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Throttle Body and the Powertrain Control Module (PCM) and between the MAP Sensor and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched, or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Search for any Technical Service Bulletins that may apply.

Were any problems found?

Yes

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

No

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