DTC P1400
Diagnostic Instructions
DTC Descriptor
| DTC P1400: Cold Start Emission Reduction
Control System |
Circuit/System Description
The catalyst must be warmed to efficiently reduce the emissions.
The cold start strategy is to reduce the amount of time it takes to
warm the catalyst. During a cold start, the engine idle speed is
elevated and spark timing is retarded to allow the catalyst to warm
quickly. This diagnostic monitors the following to build an exhaust
energy model:
| • |
Engine coolant
temperature |
The actual model is then compared to the expected exhaust energy
model.
Conditions for Running the DTC
| • |
DTCs P0101, P0102, P0103,
P0106, P0107, P0108, P0112, P0113, P0114, P0116, P0117, P0118,
P0121, P0122, P0123, P0222, P0223, P0201, P0202, P0203, P0204,
P0300, P0301, P0302, P0303, P0304, P0335, P0336, P0351, P0352,
P0353, P0354, P0502, P0503, P0506, P0507, P0641, P0651, P0697,
P06A3, P0806, P0807, P080A, P2122, P2123, P2125, P2127, P2128,
P2135, P2138, and P2544 are not set. |
| • |
The engine is idling less than
30 s. |
| • |
The engine coolant temperature
(ECT) sensor is greater than -10°C (14°F). |
| • |
The calculated 3-way catalyst
temperature is less than 350°C (662°F). |
| • |
The ECM will exit the
diagnostic if the calculated 3-way catalyst temperature is greater
than 420°C (788°F) when the engine run time is greater than
30 s. |
| • |
The ECM will exit the
diagnostic if the engine run time is greater than 90 s.
|
| • |
The vehicle speed is less than
2 km/h (1 MPH). |
| • |
The engine is at idle with no
input from the accelerator pedal. |
This DTC runs within the first 90 s of start-up. This diagnostic
runs once per trip when a cold start has been determined.
Conditions for Setting the DTC
The actual exhaust energy model does not match the expected
exhaust energy model.
Action Taken When the DTC Sets
DTC P1400 is a Type A DTC.
Conditions for Clearing the DTC
DTC P1400 is a Type A DTC.
Reference Information
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
| 1. |
Ignition OFF, allow the engine
to cool. |
| 2. |
Engine idling for at least 2
min, observe the scan tool DTC information. DTC P1400 should run
and pass. |
| 3. |
Operate the vehicle within the
Conditions for Running the DTC to verify the DTC does not reset.
You may also operate the vehicle within the conditions that you
observed from the Freeze Frame/Failure Records data. |
Circuit/System Testing
| 1. |
Inspect the air intake system
for the following: |
| |
• |
Damage, restriction, or
modification |
| |
• |
Dirty or deteriorating air
filter element |
| |
• |
Crankcase ventilation system
for correct operation. |
| |
• |
Vacuum leak and other
unmetered air downstream of the mass air flow (MAF) sensor
|
| 2. |
Inspect the exhaust system for
the following: |
| 3. |
Inspect for an engine
mechanical condition that could alter the air flow into the
combustion chamber. Refer to
Symptoms - Engine Mechanical . |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic
procedure.
|
