Checks
| Action
|
Definition:
The engine has a power variation under a steady throttle or cruise. The vehicle
feels as if it speeds up and slows down with no change in the accelerator
pedal.
|
Preliminary
Checks
|
• | Refer to Important Preliminary Checks
. |
• | Be sure the driver understands the Torque Converter Clutch operation. |
• | Be sure the driver understands the A/C Compressor operation. |
• | Use the scan tool to make sure the reading of the Vehicle Speed
Sensor (VSS) matches the vehicle speedometer. This excludes vehicles with
electronic transmissions where some variation between the VSS and the speedometer
is normal. |
|
Sensor Check
| Check the (Heated) Oxygen
Sensor (HO2S) performance. Refer to
DTC P0131 HO2S Circuit Low Voltage Bank 1 Sensor 1
. Refer to
DTC P0132 HO2S Circuit High Voltage Bank 1 Sensor 1
.
Refer to
DTC P0133 HO2S Slow Response Bank 1 Sensor 1
. Refer to
DTC P0134 HO2S Circuit Insufficient Activity Bank 1 Sensor 1
. Refer to
DTC P0135 HO2S Heater Performance Bank 1 Sensor 1
. Refer
to
DTC P0137 HO2S Circuit Low Voltage Bank 1 Sensor 2
. Refer to
DTC P0138 HO2S Circuit High Voltage Bank 1 Sensor 2
. Refer to
DTC P0140 HO2S Circuit Insufficient Activity Bank 1 Sensor 2
.
Refer to
DTC P0141 HO2S Heater Performance Bank 1 Sensor 2
.
|
Fuel System Checks
|
• | Check for a Rich or Lean symptom that causes the condition. Drive
the vehicle at the speed of the complaint. Monitoring the Fuel Trim will help
identify the problem. |
• | Check the in-line fuel filter for a restrictions. |
|
Ignition
System Checks
|
• | Check the spark plugs. Remove the plugs and inspect them for the
following conditions: |
|
Additional
Checks
|
• | Check the Control Module grounds for being clean, tight, and in
their proper locations. |
• | Check the generator output voltage. |
• | Check the vacuum hoses for kinks or leaks. Refer to the Vehicle
Emission Control Information label. |
• | Check for Torque Converter Clutch (TCC) operation. Refer to Transmissions. |
|