P1270 - Engine RPM Or Vehicle Speed Limiter Reached

4-106 Powertrain DTC Charts and Descriptions

Diagnostic Trouble Code (DTC) Charts and Descriptions

P1270 - Engine RPM Or Vehicle Speed Limiter Reached

Description: This DTC sets when the vehicle has been operated in a manner which caused the engine or vehicle to exceed a

calibration limit. The engine RPM and vehicle speed are continuously monitored and evaluated by the PCM. This DTC sets when the RPM or vehicle speed falls out of a calibrated range. For additional information on the engine RPM/vehicle speed limiter, refer to Section 1, Powertrain Control Software.

Possible Causes: • Wheel slippage (water, ice, mud, and snow)

• Excessive engine RPM in NEUTRAL or operated in the wrong transmission gear

• Vehicle driven at a high rate of speed

Diagnostic Aids: If there are no other symptoms, return the vehicle to the customer with information about the DTC.

If a symptom is present, refer to Section 3, No Diagnostic Trouble Codes (DTCs) Present Symptom Chart Index.

Application Key On Engine Off Key On Engine Running Continuous Memory

All Refer to the Description, Possible Causes and Diagnostic Aids for the DTC.

P1285 - Cylinder Head Over Temperature Condition

Description: This DTC sets when an engine overheat condition was sensed by the cylinder head temperature (CHT) sensor.

Possible Causes: • Low engine coolant level

• Base engine concerns

• Engine cooling system concerns

• CHT sensor concern

Diagnostic Aids: On some applications when this fault occurs the engine temperature warning indicator illuminates or forces the

temperature gauge to the full H (hot) zone. The warning indicator can be triggered by either grounding the engine temperature warning circuit when wired to the PCM, or by sending a PCM network message to the instrument panel cluster (IPC).

Application Key On Engine Off Key On Engine Running Continuous Memory

All GO to Pinpoint Test DL.

P1288 - Cylinder Head Temperature (CHT) Sensor Out Of Self-Test Range

Description: This DTC sets when the CHT sensor is out of self-test range. The engine is not at a normal operating

temperature.

Possible Causes: • Cold engine

• Engine overheating

• Low engine coolant level

Diagnostic Aids: Bring the engine to operating temperature. If cold, repeat the self-test. If the engine overheats, check the cooling

system. Refer to the Workshop Manual Section 303-03, Engine Cooling, The Engine Overheats for cooling system diagnosis.

Application Key On Engine Off Key On Engine Running Continuous Memory

All Refer to the Description, Possible Causes and Diagnostic Aids for the DTC.

P1289 - Cylinder Head Temperature (CHT) Sensor Circuit High

Description: This DTC sets when a CHT circuit open concern is present.

Possible Causes: • CHT circuit open

• CHT circuit short to voltage

• Damaged CHT sensor

• Damaged CHT wiring harness or connector

Diagnostic Aids: The DTC P0118 may also be reported when this DTC sets. Either of these DTCs illuminate the malfunction

indicator lamp (MIL).

Application Key On Engine Off Key On Engine Running Continuous Memory

All GO to Pinpoint Test DL.

P128A - Cylinder Head Temperature (CHT) Sensor Circuit Intermittent/Erratic

Description: This DTC sets when the CHT circuit is intermittently open or short while the engine is running.

2016 Powertrain Control/Emissions Diagnosis, Gasoline Engines, 3/2015