P0122

CIRCUIT DESCRIPTION

The Throttle Position sensor is potentiometer. A 5 volt reference is provided on CKT 605 and ground is provided on CKT 808. The Throttle Position (TP) sensor signal CKT 417 varies between ground and 5 volts based on the position of the throttle plates. At low throttle angle, the TP sensor signal voltage is low. The PCM uses TP sensor information to determine idle, Wide Open Throttle (WOT), deceleration enleanment and acceleration enrichment. DTC P0122 sets when the PCM detects a TP sensor signal that is too low. The PCM tests the TP sensor feedback every 100 ms. If the TP sensor reading is 0.1 volts or less, such as when the signal is open or shorted to ground, the PCM sets DTC P0122.

CONDITIONS FOR SETTING THE DTC

Test Condition

Engine speed 600 RPM or greater.

Failure Condition

The TP sensor reading is 0.1 volts or less.

ACTION TAKEN WHEN THE DTC SETS

^ PCM disables the torque converter clutch.
^ PCM calculates a TP sensor value based on MAP and engine speed inputs.
^ PCM disables fourth gear.
^ The PCM will illuminate the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
^ The PCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC

^ The PCM will turn the MIL OFF after three consecutive drive trips that the diagnostic runs and does not fail.
^ A Last Test Failed (current) DTC will clear when the diagnostic runs and does not fail.
^ A History DTC will clear after forty consecutive warm-up cycles with no failures of any emission related diagnostic test.
^ PCM battery voltage is interrupted.
^ Using a Scan tool.

DIAGNOSTIC AIDS

If fault is not present perform Powertrain Ground Check and also review Failure Rec. to determine conditions under which and how long ago the DTC set.

TEST DESCRIPTION

Number(s) below refer to the step number(s) on the Diagnostic Table.

2. With TP sensor or wiring open, TP sensor display will read 0.1 volts or less.
3. Checking for open TP sensor or open wiring. If the display value stays less than 4.96 volts with the TP sensor terminals A and C jumpered together, the problem is in the wiring.
4. Voltage should be greater than 0.5 volt if CKT 605 is not open or shorted to ground.
5. If voltage at TP sensor connector terminal A is 4.5 volts or more, the TP Sensor Signal circuit could be shorted to ground.
6. Use the MAP display to determine it a 5 volt reference problem exists.
7. If there is high resistance, the TP Sensor Signal circuit could be open. If low resistance exists the PCM may be faulty.
8. Checking the 5 volt reference feed to the TP sensor. The EGR, Brake Booster Vacuum (BBV) sensor and MAP 5 volt reference circuits must also be checked for a short to ground which could cause this DTC to set.