Checks
| Action
|
DEFINITION: The engine delivers less than expected power. There is little
or no increase in speed when partially applying the accelerator pedal.
|
Preliminary
Checks
|
| • | Search for service bulletins. |
| • | Compare the customer's vehicle with a similar unit. Verify that
the customer has an actual problem. |
| | Important: Do not compare the power output of the vehicle operating on natural
gas to a vehicle operating on gasoline as the fuels do have different drive
feel characteristics.
|
| • | Remove the air filter and inspect for dirt or restrictions. |
| • | Verify the transmission shift pattern and the downshift operation.
Refer to Range Reference in Automatic Transaxle - 3T40 or Range Reference
in Automatic Transaxle - 4T40E in the J Platform Service Manual. |
|
Fuel System Checks
|
| • | Verify the proper ignition output voltage using the J 26792
or the equivalent. |
| • | Inspect the knock sensor (KS). Refer to DTC P0325 Knock Sensor
Circuit in Engine Controls - 2.2L in the J Platform Service Manual. |
| • | Verify that the correct PCM bi-fuel software is installed. |
|
Sensor Checks
|
| • | Inspect the oxygen sensor (O2S) for contamination and performance.
Refer to O2S Replacement in Engine Controls - 2.2L in the J Platform Service
Manual. |
| • | Verify proper operation of the TP sensor. |
| • | Verify proper operation of the MAP sensor. |
| • | Verify proper operation of the ECT sensor. |
| • | Verify proper operation of the EGR system. |
|
Exhaust System Checks
| Inspect the exhaust system for possible restrictions and the following
conditions:
| • | Inspect the exhaust system for damaged or collapsed pipes. |
| • | Inspect the muffler for signs of heat distress or for possible
internal failure. |
| • | Inspect for a possible plugged catalytic converter. Refer to Restricted
Exhaust System Check in Engine Controls - 2.2L in the J Platform Service
Manual. |
|
Engine Mechanical Check
| Inspect the engine for proper operation of the following items:
| • | Improper or worn camshaft |
|
Additional Checks
|
| • | Inspect the control module grounds. The grounds should be clean,
tight and in their proper locations. |
| • | Inspect for an intermittent EGR problem. Refer to EGR System Diagnosis
in Engine Controls - 2.2L in the J Platform Service Manual. |
| • | Verify the A/C operation. Refer to A/C Compressor Circuit Control
Diagnosis in Engine Controls - 2.2L in the J Platform Service Manual. |
| • | Verify proper torque converter clutch (TCC) operation. Refer to
Torque Converter Clutch Diagnosis in Automatic Transaxle - 3T40 or Torque
Converter Clutch Diagnosis in Automatic Transaxle - 4T40E in the J Platform
Service Manual. |
| • | Verify the generator output voltage. Refer to Generator Usage
in Engine Electrical in the J Platform Service Manual. |
| • | Inspect for a stretched throttle cable. |
If all the procedures have been completed and no malfunction has been
found, review and inspect the following items:
| • | Visually and physically inspect all electrical connections within
the suspected circuit and systems. |
|
