Override

Description:
The PCM override feature allows testing of certain system functions regardless of normal program instructions.

Upon selecting a test, the current operation of that function will be displayed on the CCDIC. The display will alternate between "--" for 1 second followed by the normal program command for 5 seconds. This alternating display is a reminder that the function is not currently being overridden.

Pressing the WARMER or COOLER buttons on the ECC panel initiates the override at which time the display will no longer alternate to "--." Generally speaking, pressing the WARMER button increases the override value while pressing the COOLER button decreases the override value (exceptions are noted in the description of the override). Upon release of the button, the display may either remain at the overridden value or automatically return to normal program control. This depends on which function is being overridden at the time. If the display remains at the override value, normal program control can be resumed in one of three ways:

1. Selection of another override test will cancel the current override.
2. Selection of another system (e.g., BCM) will cancel the current override.
3. On some system overrides, overriding the value beyond either extreme (0 or 99) will display "--" momentarily and jump to the opposite extreme. If the button is released while "--" is displayed, normal program control will resume and the display will again alternate.

PS00 NONE
No Outputs. No PCM Outputs can be overridden when PS00 is selected.

PS01 TCC SOL
Torque Converter Clutch Solenoid. PS01 may be used to override the commanded state of the TCC solenoid. When PS01 is selected, the current state of the TCC solenoid will be displayed for five seconds followed by "--" for one second to indicate normal PCM control of the TCC solenoid. During both normal PCM control and override control, a display of "00" means the TCC solenoid is de-energized and a display of "99" means it is energized. The TCC solenoid may be overridden off by pressing and holding the COOLER button or overridden on by pressing and holding the WARMER button. In either case, releasing the button will return the TCC solenoid to normal PCM control. Keep in mind that the TCC is only able to be engaged when the transaxle is in 3rd or 4th gear.

PS02 EGR SOL
Exhaust Gas Recirculation Solenoid. PS02 may be used to override normal EGR solenoid control. When PS02 is first selected, the display will alternate between "--" for one second and current commanded EGR pintle position (as a percent of full travel). Pressing the WARMER button will increment commanded EGR pintle position up to a maximum of 99%. Pressing the COOLER button will decrement commanded EGR pintle position down to a minimum of 0%. Current commanded EGR pintle position will be displayed throughout the override.

PS03 ISC MOTOR
Idle Speed Control Motor. The ISC motor may be overridden under certain conditions using PS03. When PS03 is first selected, the display will alternate between "--" for one second and "50" for three seconds to indicate normal PCM control of the ISC motor. This will continue until an ISC extend or retract override is attempted. If at any point an override is attempted without meeting the conditions stated below, "--" will be displayed.

ISC Extend:

The ISC motor may be extended using the WARMER button only under the following conditions:

^ Engine not running.
^ Vehicle speed is 0.
^ Transaxle is in Park or Neutral.
^ Throttle Position Switch is closed or throttle angle (PD01) is less than 1.44 degrees.

When these conditions are met and the WARMER button is pressed, the ISC motor will extend as far as it can and "99" will be displayed.

ISC Retract:

The ISC motor may be retracted using the COOLER button only under the following conditions:

^ Vehicle speed is 0.
^ Transaxle is in Park or Neutral.

When these conditions are met and the COOLER button is pressed, the ISC motor will retract until the throttle switch opens and "00" will be displayed. While in the ISC retract override, the EGR solenoid and the generator will be commanded "OFF" and ignition control will try to maintain at least 450 rpm.

PS04 INJECTOR
Fuel Injector Disable. PS04 may be used to individually disable injectors to note the effect on engine performance. The following conditions must be met to allow injector override:

^ Vehicle speed is 0
^ Transaxle in Park or Neutral

If the above conditions are not met, fuel injector override will be suspended until these conditions are met at which time the override will resume with injector #1. When PS04 is first selected, the display will alternate between "--," for one second and "01" for five seconds ("01" signifying injector #1). Once PS04 is selected, the WARMER button is used to select the injector to be tested and the COOLER button is used to disable the selected injector. Pressing the WARMER button will increment the display and the injector number selected for testing from #1 through #8 and back to #1 again (injector number corresponds to cylinder number). Pressing the COOLER button disables the selected injector only while the button is held. While the injector is disabled, "00" will be displayed. While PS04 override is selected, the A/C clutch and generator will be disabled. Additionally, while an injector is being disabled, ISC motor position and Short Term Fuel Trims are frozen.

PS05 FUEL RELAY
Fuel pump relay override. PS05 may be used to energize or de-energize the fuel pump relay. The following conditions must be met to override the fuel pump relay:

^ Vehicle speed is 0
^ Transaxle in park or neutral

When PSO5 is first selected, the display will alternate between "--," for one second and the current state of the fuel pump relay output for five seconds ("00" means fuel pump relay "OFF" and "99" means fuel pump relay "ON"). Pressing the COOLER button will turn the relay "OFF" and display "00." Pressing the WARMER button will turn the relay "ON" and display "99." The override will only be active while the COOLER or WARMER button is pressed. Normal control will resume when the button is released.

PS06 AIR PUMP
Not used. No PCM Outputs can be overridden when PS06 is selected.

PS07 C/C FBK
PS07 may be used to override commanded servo position through the use of the cruise control vent and vacuum solenoids. Servo override is not allowed with the engine running. The Cruise "ON/OFF" switch must be "ON" to operate the Cruise Control Servo. When PS07 is first selected, the commanded servo position will be set to 0 and the display will alternate between "--" for one second and "00" for five seconds. Pressing the WARMER button will cause the commanded servo position to increment. Pressing the COOLER button will cause the commanded servo position to decrement. Using the WARMER and COOLER buttons, the commanded servo position may be overridden from 0% to 99%. At "99" if the WARMER button is held, the commanded servo position will wrap to "00" and at "00" if the COOLER button is held, the commanded servo position will wrap to "99." The engine must be run prior to entering this override (to build up a vacuum reserve) if cruise servo movement is desired.

PS08 FAN SPEED
Cooling Fan Relays. PS08 may be used to override the cooling fan relays. When PS08 is selected, the current state of the high and low speed fan relay outputs will be displayed as two digits. The left digit represents the low speed fan relay state ("1" means energized, "0" means de-energized) and the right digit represents the high speed fan relay state. Pressing the WARMER button changes the high speed fan relay state to "1" if it was "0" or to "0" if it was "1." Pressing the COOLER button changes the low speed fan relay state to "1" if it was "0" or to "0" if it was "1." The table below shows the four possible states of the cooling fan relays and their corresponding cooling fan operation.

Output State Cooling Fan Operation

00 Fans off
01 Right fan on high
10 Both fans on low
11 Both fans on high

PS09 SPARK OVER
Temporary Spark Advance Override. PS09 may be used to temporarily override the spark advance used by the ignition system. When PS09 is selected, the current spark advance will be displayed. While the spark advance is being overridden, the PCM will continue to compute the normal spark advance based on engine data. This value will be used as a maximum spark advance override. If at any time, the override spark advance exceeds normal spark advance, the normal spark advance will be used and displayed. To initiate spark override, the COOLER button must be pressed. Prior to this, the WARMER button will do nothing. When the COOLER button is first pressed, the spark advance will be set to 10 degrees. Afterwards, the WARMER button will increment spark advance up to the maximum advance calculated by the PCM and the COOLER button will decrement spark advance down to a minimum of 0. The current spark advance will be displayed for the duration of the override.

PS10 INJ FLOW
Injector Flow Override. PS10 may be used to fire each injector for a specific period of time thereby comparing injector flow. The following conditions must be met to override the injectors:

^ Vehicle speed is 0.
^ Transaxle in park or neutral.
^ Engine speed is 0.

If the above conditions are not met, fuel injector override will be suspended until these conditions are met at which time the override will resume with injector #8. When PS10 is first selected, the display will alternate between "--," for one second and "08" for five seconds ("08" signifying injector #8). Once PS10 is selected, the COOLER button is used to select the injector to be tested and the WARMER button is used to fire the selected injector. Pressing the COOLER button will decrement the display and the injector number selected for testing from #8 through #1 and back to #8 again (injector number corresponds to cylinder number). Pressing the WARMER button fires the selected injector. While the injector is fired, "99" will be displayed. PS10 will only allow each injector to be fired once between engine runs to avoid flooding.

PS11 TRANS OVER
Transaxle Shift Override. PS11 may be used to override Shift A and Shift "3" solenoid outputs and thus control shifts while in drive. The following conditions must be met to override shifts:

^ Gear selector in D4.
^ Vehicle speed less than 65 mph.

If these conditions are not met, transaxle shift override will not be allowed and '= =' will be displayed.

When PS11 is selected and the above conditions are met, the current commanded gear will be displayed. Pressing the WARMER button will cause the transaxle to upshift and display the new commanded gear. Pressing the COOLER button will cause the transaxle to downshift and display the new commanded gear. A 3-2 downshift is not allowed above 58 mph. A 2-1 downshift is not allowed above 30 mph. If either is commanded while in overrides, the downshift will not occur and "= =" will be displayed while the COOLER button is pressed. While in transaxle shift override, the [1][2]Torque Converter Clutch and Transaxle Pressure Control Solenoids will be disabled.

PS12 BLCK LEARN
Long Term Fuel Trim Reset. PSi2 may be used to reset Long Term Fuel Trim values to 128 (neutral). When PS12 is selected, "00" will be displayed. Pressing the COOLER button will cause all Long Term Fuel Trim values to reset to 128 and "90" to be displayed. Pressing the WARMER button does nothing.

PS13 TPS LEARN
TP Sensor/Idle Learn and Garage Shift Adapt Reset. PS13 may be used to reset the Throttle Position Sensor Learn and Idle Learn values and/or the Garage Shift Adapt values. When PS13 is selected, "00" will be displayed. Pressing the WARMER button will reset the Garage Shift Adapt values and cause "09" to be displayed. Pressing the COOLER button will reset Throttle Position Sensor Learn and Idle Learn values and cause "90" to be displayed.

NOTE: A normal power down cycle (key off for 30 seconds) must follow the Throttle Position Sensor/Idle Learn reset in order for the learned Throttle Position values to reset. Each reset is allowed only once per ignition cycle.

PS14 TRAN ADAPT
Transaxle Upshift and Steady State Adapt Reset. PS14 may be used to reset the transaxle upshift adapt values and/or the transaxle steady state adapt values. When PS14 is selected, "00" will be displayed. Pressing the WARMER button will reset the Transaxle Steady State Adapt values and cause "09" to be displayed. Pressing the COOLER button will reset Transaxle Upshift Adapt values and cause "90" to be displayed.

PS15
Transaxle Oil Life. A transaxle oil life index is calculated and maintained by the PCM. PS15 may be used to change the transaxle oil life index. When PS15 is selected, the current transaxle oil life index (in percent) will be displayed. "--" is displayed to indicate 100. Pressing the WARMER button will increment the transaxle oil life index up to a maximum of 100 (displayed as "--"). Pressing the COOLER button will decrement the transaxle oil life index down to a minimum of 0. Note: A normal power down cycle (key "OFF" for 30 seconds) must follow this override in order for the new transaxle oil life index value to be saved.

PS20 FORCE MTR
Transaxle Pressure Control. PS20 may be used to override control of the Transaxle Pressure Control Solenoid thus overriding transaxle line pressure. When PS20 is selected, the display will alternate between "--," for one second and commanded transaxle line pressure (in PSI) for five seconds until either the WARMER or COOLER button is pressed. PS20 override operates differently depending on the gear selector position:Gear selector in park or neutral:

Vehicle speed must be 0, the A/C clutch must be disabled, and engine speed must be between 1150 and 1250. When these conditions are true, the WARMER button may be used to increment commanded line pressure and the COOLER button may be used to decrement commanded line pressure. Current commanded line pressure will be displayed for the duration of the override.

Gear selector not In park or neutral:

Pressing the WARMER button will increment commanded line pressure. Pressing the COOLER button will do nothing. Current commanded line pressure will be displayed for the duration of the override.

PS21
Knock Sensor Test. PS21 may be used to test the knock sensor system. The following conditions must be met to test the knock sensor system:

^ Transaxle in 4th gear.
^ Throttle angle greater than 33.6 degrees.
^ Coolant temperature greater than 80 degrees C.

When PS21 is selected, the display will alternate between "--," for one second and "99" for five seconds. If the COOLER button is pressed and held, the display will change to "00" and the following chain of events will be set in action:

^ TCC will be engaged.
^ 3 seconds elapse.
^ Spark advance will be ramped up to 21 degrees and held there for 7.4 seconds.

NOTE: The COOLER button must be held for the duration of the test. If knock sensor activity is detected anytime during the test, the display will change to "11" and the test will be suspended. If the end of the test is reached and no knock sensor activity was detected, the display will change to "22."

PS22
Permanent Spark Retard. PS22 may be used to permanently retard the ignition base timing of 100 BTDC by up to 40 When PS22 is selected, the current permanent spark override will be displayed either "00" for no retard or the number of degrees retard preceded by a "9" (e.g. "94" for 40 retard). Pressing the COOLER button retards the base timing to a maximum of 40 Pressing the WARMER button will display "00" and removes all spark retard resetting timing to the base timing of 100 BTDC.

NOTE: A normal power down cycle (key off for 30 seconds) must follow this override in order for the new permanent spark retard value to be saved.

PS23
Generator Enable/Disable. PS23 may be used to enable or disable generator charging using the PCM's L-terminal output. PS23 is only allowed under the following conditions:

^ Gear selector in Park or Neutral.
^ Engine running.

If PS23 override is attempted and the above conditions are not true, "=" will be displayed. When PS23 is selected, the display will alternate between "--," for one second and the current state of the PCM's L-terminal output ("99" for enabled and "00" for disabled) for five seconds. The WARMER button will enable generator charging. The COOLER button will disable generator charging. The current state of the PCM's L-terminal output will be displayed for the duration of the override.

PS24
Traction Control Disable. PS24 may be used to temporarily disable traction control. When PS24 is selected, the display will alternate between "--" for one second and the current state of traction control disable override ("99" for override active and "00" for override not active). Pressing the WARMER button will and disable traction control for the next eleven ignition cycles and display "99." Pressing the COOLER button will allow normal program control of traction control and display "00."

NOTE: The "TRACTION CONTROL DISABLED" message will appear for the duration of this override and should be considered normal.