Modes of Operation

In this mode, the Logic Module or SMEC compensates for the failure of certain components by suibstituting information from other sources. If the Logic Module or SMEC senses incorrect data at all from the MAP Sensor, Throttle Position Sensor, Charge Temperature Sensor, Coolant Temperature Sensor or Battery Voltage Sensor, the system is placed into Limp In Mode and the Power Loss/Check Engine Lamp on instrument panel is activated.








The following is a description of each "limp-in" mode:

1. M.A.P. (Manifold Absolute Pressure) Sensor. If this signal is either too low, (less than .02 volts) too high, (greater than 4.7 volts) or not changing fault codes 13 and/or 14 are recorded in memory and the "power loss" lamp is turned "ON". At this time the throttle position and engine speed signals are used by the logic module to generate a modified M.A.P. sensor signal in place of the failed one. While in this "limp-in" mode the automatic idle speed motor is driven to its minimum position.
2. Throttle Position Sensor. If this signal is either too low (less than .16 volts) or too high (greater than 4.7 volts) fault code 24 is recorded in memory and the "check engine" lamp is turned "ON". At this time the M.A.P. sensor signal is used by the single module engine controller (SMEC) to generate a modified throttle signal in place of the failed one.
3. Coolant Temperature Sensor. If this signal is above 4.96 volts when the engine is cold or below .51 volts with a warm engine fault code 22 is recorded in memory and the "check engine" lamp is turned "ON". At this time the SMEC will set in a fixed value of 70 degrees F for Turbo I and Turbo II will use the charge temperature signal. The radiator fan will run continuously in this mode.
4. Charge Temperature Sensor (Turbo II) If this signal is above 4.98 or below .06 volts fault code 23 is recorded in memory and the "check engine" lamp is turned "ON". At this time the SMEC will use a default temperature in place of the failed charge sensor.
5. Wastegate Control Solenoid. If the SMEC senses incorrect voltage at the wastegate solenoid, fault code 36 is recorded in memory and the "check engine" lamp is turned on. While in this mode the overboost shutoff point is decreased to 13.1 psi.
6. Battery Voltage Sense. If this signal drops below 4 volts after the engine has been running for one minute fault code 16 is recorded in memory and the "check engine" lamp is turned "ON". At this time the SMEC will operated the charging system at a fixed rate.
7. Battery Voltage Too High. If the SMEC senses the battery sense voltage is more than 1 volt above the desired control voltage, fault code 46 is recorded in memory and the "check engine" lamp is turned "ON".


If these sensor signals return to within specifications, while the engine is running, the system will return to normal operation but the "check engine" lamp will stay "ON" until the engine is restarted. The fault code will remain in memory for evaluation by the SMEC but will be cleared after 50 to 100 engine starts if the fault does not happen again.