TEST
ACTION
APPLICABILITY
1
NOTE: Diagnose any TP Sensor or MAP Sensor component DTCs before
continuing.
NOTE: If the P0501 - No Vehicle Speed Signal is set along with this DTC,
refer to the P0501 diagnostics before continuing.
NOTE: The throttle plate and linkage must be free from binding and carbon
build up, ensure the throttle plate is at the idle position, ensure the throttle
plate is at the idle position.
Ignition on, engine not running.
With the DRBIII
t, read DTCs and record the related Freeze Frame data.
Is the Good Trip Counter displayed and equal to zero?
All
Yes
→ Go To 2
No
→ Refer to the INTERMITTENT CONDITION symptom in the
Driveability category.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
2
NOTE: This code is enabled on engines with a plastic intake manifold and is
intended to shut down the engine if a large crack occurs in the intake
manifold.
NOTE: A large vacuum leak is most likely the cause of this DTC.
Inspect the Intake Manifold for leaks and cracks.
Inspect the Power Brake Booster for any vacuum leaks.
Inspect the PCV system for proper operation or any vacuum leaks.
Were any vacuum leaks found?
All
Yes
→ Repair the vacuum leak as necessary.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
No
→ Go To 3
3
Start the engine.
With the DRBIII
t, monitor the MAP Sensor voltage.
Snap the throttle.
Does the MAP Sensor voltage vary from below 2.0 volts at idle to above 3.5 volts?
All
Yes
→ Go To 4
No
→ Go To 12
4
Ignition on, engine not running.
With the DRBIII
t, monitor the TP Sensor voltage while slowly depressing the
throttle pedal from the idle position to the wide open throttle position.
Does the voltage start approximately at 0.8 volts and go above 3.5 volts with a smooth
transition?
All
Yes
→ Refer to the INTERMITTENT CONDITION symptom in the
Driveability category.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
No
→ Go To 5
266
DRIVEABILITY - NGC
P2074-MANIFOLD PRESSURE/THROTTLE POSITION CORRELATION -
HIGH FLOW/VACUUM LEAK —
Continued