P080

IAT, MAP And TPS Circuits:

CIRCUIT DESCRIPTION
This diagnostic test checks to see if initial Throttle Position (TP) Sensor/Learn and Idle Learn values have been stored in the Powertrain Control Module (PCM). If these values have not been stored, Code P080 is set. Performing the TP Sensor/Idle Learn Procedure described below will cause Code P080 to become history.

TP SENSOR/IDLE LEARN PROCEDURE

IMPORTANT: Make sure nothing is touching or obstructing the accelerator or brake pedals, the heated windshield is turned off, and there is no load on the power steering during the TP learn procedure because this will prevent the PCM from performing the learn routine.


1. Turn ignition to "ON" (engine not running).
2. Enter diagnostics.
3. Turn ignition to "OFF."
4. Wait a minimum of 20 seconds.
5. Turn ignition to "ON" (engine not running).
6. Enter diagnostics.
7. Turn ignition to "OFF."
8. Wait a minimum of 20 seconds.
9. Turn ignition to "ON" (engine not running).
10. Enter diagnostics.
11. Turn ignition to "OFF."
12. Wait a minimum of 20 seconds.

IMPORTANT: Make sure that the outside air temperature is at least 10°C (50°F) so that the A/C compressor will turn "ON."

13. Start the engine.
14. Allow the vehicle to idle continuously until the coolant temperature is 80°C, then idle an additional 5 minutes.
15. Apply the brakes and place the transaxle in "DRIVE" range.
16. Turn the Climate Control Center (CCC) to "OFF" and allow the engine to idle for 30 seconds.
17. Turn the CCC to "AUTO" and allow the engine to idle for another 30 seconds.
18. Place the transaxle in "PARK" range and turn ignition to "OFF."

IMPORTANT: Because of the engine load differences with the A/C "ON" verses "OFF" the Idle Learn must be performed under both conditions.

NOTE: If code PO80 does not change to history following the completion of this procedure, refer to "NOTES ON FAULT TREE" in this article.

TEST CONDITIONS
Test continuously.

FAILURE CONDITIONS
No TP sensor learn value is stored.
OR
No idle learn value is stored.

ACTION TAKEN
PCM turns "ON" the Malfunction Indicator Lamp (MIL) (Service Engine Soon).

NOTES ON FAULT TREE
If Code P080 does not change to history following the completion of the TP Sensor/Idle Learn Procedure, this may be due to incorrect or erratic signals from the following sensors:

^ TP Switch
^ TP Sensor
^ Vehicle Speed Sensor
^ Transaxle Range Switch (Park/Neutral Input)
^ Power Steering Pressure Switch
^ Brake Switch

High electrical loads may disable TP Sensor/Idle Learn. Components that may produce a high electrical load are the headlamps, the rear defogger, high HVAC blower and the cooling fans. If difficulty is encountered learning TP Sensor/Idle values (i.e. Code P080 remains current), turn "OFF" these high electrical loads. Also, it is important to accelerate the engine above 1000 rpm after turning "OFF" the above components because the PCM will think it is still under a high electrical load until it checks the system again (when engine rpm exceeds 1000 rpm). Furthermore, since the cooling fans cannot be manually controlled, engine coolant temperature must be below 105°C and A/C refrigerant temperature must be below 51°C in order to turn "OFF" the high speed cooling fans and their high electrical load.

Code P080 may also remain current if the idle is rough or unstable. Correct problems with these sensor's signals or the idle before attempting to perform the TP Sensor/Idle Learn.