2010 Cadillac CTS Sedan AWD V6-3.6L Page 1416
engine control module (ECM) detects one of the following conditions:
* The FTP sensor signal voltage is not within a calibrated range on a cold start-up.
* The FTP sensor signal oscillates greater than a calibrated amount when vehicle speed is within a predetermined range.
The following table illustrates the relationship between FTP sensor signal voltage and the EVAP system pressure/vacuum.
Conditions for Running the DTC
P0450
* DTC P0100, P0101, P0102, P0103, P0116, P0117, P0118, P0119, P0443, P0449, P0458, P0459, P0498, P0499, P050A, P0506, P0507,
P0700, P2227, P2228, or P2229 is not set.
* The engine is operating.
* The ambient air temperature is greater than -7掳C (+19掳F).
* The vehicle speed is less than 31 km/h (19 mph).
* The ECM has commanded the EVAP canister vent valve open for greater than 3 seconds, 4 seconds for LLT.
* DTC P0450 runs continuously once the above conditions are met for approximately 25 seconds.
P0451 Condition 1
* DTC P0100, P0101, P0102, P0103, P0116, P0117, P0118, P0119, P0443, P0449, P0458, P0459, P0498, P0499, P050A, P0506, P0507,
P0700, P2227, P2228, or P2229 is not set.
* The engine is operating for greater than 1 second.
* The engine is idling.
* The ambient air temperature is greater than -7掳C (+19掳F).
* The vehicle speed is less than 10 km/h (6 mph) for greater than 29 seconds.
* The BARO is greater than 68 kPa.
* The fuel level is between 11-88 percent.
* The ECM has commanded the EVAP canister purge solenoid ON.
* The ECM has commanded the EVAP canister vent valve closed for greater than 4 seconds.
* DTC P0451 runs continuously when the above conditions are met for approximately 25 seconds.
P0451 Condition 2
* DTC P0100, P0101, P0102, P0103, P0116, P0117, P0118, P0119, P0443, P0449, P0458, P0459, P0498, P0499, P050A, P0506, P0507,
P0700, P2227, P2228, or P2229 is not set.
* The engine is operating.
* The BARO is greater than 68 kPa.
* The fuel level is between 11-88 percent.
* The ECM has commanded the EVAP canister purge solenoid OFF.
* The ECM has commanded the EVAP canister vent valve open.
OR
* The fuel level is less than 60 percent, 73 percent for LLT.
* The vehicle speed is between 10-76 km/h (6-47 mph) for greater than 30 seconds.
* The ECM has commanded the EVAP canister purge solenoid ON.
OR
* The calculated ambient air temperature is between 4-35掳C (39-95掳F) for greater than 3 seconds.
* DTC P0451 runs continuously when the above conditions are met for approximately 7 seconds.
Conditions for Setting the DTC
P0450
The ECM detects that the FTP sensor signal oscillates greater than 6.09 mm/Hg (3.26 in. H2O) for 4 seconds, or for a cumulative of 30 seconds.
P0451
* The ECM detects that the FTP is less than -26.2 mm/Hg (-14.1 in. H2O) or greater than 11.0 mm/Hg (5.9 in. H2O) for 4 seconds or for a
cumulative of 30 seconds.
OR
* The ECM detects a change in the zero point of FTP sensor signal greater than +/-5.16 mm/Hg (2.76 in. H2O) from the zero point at start up
for 4 seconds, or a cumulative of 30 seconds.
Action Taken When the DTC Sets
DTCs P0450 and P0451 are Type B DTCs.
Conditions for Clearing the MIL/DTC
