• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
The catalytic converter must be warmed to efficiently reduce the emissions. The cold start strategy is to reduce the amount of time it takes to warm the catalytic converter. 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 speed |
• | Spark advance |
• | Throttle position |
• | Engine airflow |
• | Engine coolant temperature |
• | Engine run time |
• | Park/Neutral position |
• | Vehicle speed |
The actual model is then compared to the expected exhaust energy model.
• | The engine is running, and a cold start has been detected. |
• | The vehicle speed is less than 2 km/h (1 mph). |
• | The throttle position sensor is less than 2 percent. |
• | The airflow per cylinder is greater than 40 mg. |
• | DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0201-P0208, P0300, P0301-P0308, P0335, P0336, P0351-P0358, P0506, P0507, P0601, P0602, P0604, P0606, P0607, P060D, P062F, P0641, P0651, P1101, P1516, P1682, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138, P2176, or P2610 are not set. |
The actual exhaust energy model does not match the expected exhaust energy model.
DTC P1400 is a Type A DTC.
DTC P1400 is a Type A DTC.
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
• | Inspect the air intake system for the following: |
- | Damage, restriction, or modification |
- | Dirty or deteriorating air filter element |
- | Crankcase ventilation system for correct operation. |
- | Water intrusion |
- | Vacuum leak and other unmetered air downstream of the MAF sensor |
- | Intake manifold leak |
• | Inspect the exhaust system for the following: |
- | Water intrusion |
- | Exhaust leak |
- | Damaged, restricted, modified or enhanced exhaust system. |
• | Inspect the engine mechanical for items that could alter the air flow into the combustion chamber. |