- On-highway Truck Engine:
- C11 (S/N: KCA1-UP)
- C13 (S/N: KCB1-UP; LEE1-UP)
- C15 (S/N: BXS1-UP; SDP1-UP; MXS1-UP; NXS1-UP)
- C7 (S/N: C7S1-UP; KAL1-UP; SAP1-UP; WAX1-UP)
- C9 (S/N: C9S1-UP; MTB1-UP; 9DG1-UP)
- C13 (S/N: KCB1-UP; LEE1-UP)
Introduction
Do not perform any procedure in this Special Instruction until you have read the information and you understand the information.
This Special Instruction provides a procedure for the diagnosis of the engine related slow acceleration or low power problems for On-highway Engines.
Instructions for Completing the Customer Questionnaire
The customer questionnaire is a way to record the history of the complaint. If nonengine sources of power or acceleration are discovered, consult the manufacturer of the chassis or the manufacturer of the transmission for assistance.
When operating a transmission at stall conditions, the vehicle must be prevented from moving. Serious injury or death may result. Both the parking brake and the service brake must be applied. The vehicle must also be blocked to prevent movement. Warn personnel to keep clear of the vehicle and its travel path. |
Illustration 1 | g01443031 |
Flow Chart for Troubleshooting Low Power or Slow Acceleration
Illustration 2 | g01562134 |
The steps that are listed in Illustration 2 correspond to the steps below. |
Discussion of Troubleshooting Procedure
The complete troubleshooting procedure is outlined in Illustration 2.
(1) The customer states that the vehicle has low power or the vehicle has slow acceleration. The customer must complete the customer questionnaire that is provided by the dealer.
Note: The dealer schedules an inspection.
(2) The dealer obtains a transmission performance report from the transmission manufacturer. The transmission performance report also includes a vehicle acceleration printout. If the answer from customer questionnaire (6) is "Yes", then obtain a transmission performance report, the engine serial number, the transmission serial number and the transmission calibrated Electronic Control Unit (ECU) part number from the other vehicle. The transmission performance report also includes a vehicle acceleration printout. If the answer to customer questionnaire number (6) is "Yes", it may be necessary to log data from the other vehicle.
(3) Ensure that the transmission performance report is obtained before the vehicle is scheduled for inspection. Ensure that the inspected vehicle matches the transmission performance report. This includes the gross vehicular weight.
(4) Torque Converter Stall Test
- Install the latest version of Cat Electronic Technician (ET). Cat ET must be configured to a resolution of 240 data points per minute.
Illustration 3 | g01549253 |
Connectors |
Illustration 4 | g01549273 |
Communication adapters |
Illustration 5 | g01549313 |
6 pin adapter for Cat ET |
Illustration 6 | g01549354 |
Complete setup |
- Configure the data log. Use the following conditions for the data log. Refer to Special Instruction, REHS3407, "Using the Caterpillar Electronic Technician (ET) Data Log". Refer to Illustration 3, Illustration 4, Illustration 5, and Illustration 6 in order to aid in the setup.
- Engine speed
- Desired engine speed
- Rated fuel limit
- FRC fuel limit
- Vehicle speed
- Boost
- Fuel delivery
- Present injection mode
- Throttle position
- Percent throttle position
- Engine percent load at current speed
- Engine speed
- An Allison Service Technician must lock the transmission into the correct gear for the torque converter stall test. A similar operation must be done for a Caterpillar transmission. This will only allow the transmission to be in the direct gear and the torque converter.
- Warm the engine and the transmission. The engine coolant temperature must be above 88 °C (190 °F). The transmission oil must be above 66 °C (150 °F).
When operating a transmission at stall conditions, the vehicle must be prevented from moving. Serious injury or death may result. Both the parking brake and the service brake must be applied. The vehicle must also be blocked to prevent movement. Warn personnel to keep clear of the vehicle and its travel path. |
- Apply the parking brake.
- Turn the fan to On.
- Start recording data.
- Fully depress the service brake. The vehicle must be in fourth gear.
- Quickly depress the throttle to the limit. Hold down the throttle for fifteen seconds.
- Place the vehicle in neutral. Allow the engine and the transmission to cool by running the engine at 1500 rpm for one minute.
- Repeat Step 8 through Step 10 three times.
(5) Stop recording the data. Save the data. Attach the data log to SIMSi.
(6) If additional assistance is needed contact your Dealer Technical Communicator for submittal to the DSN.
(7) The vehicle engine meets the torque converter stall test or the vehicle engine exceeds the torque converter stall test.
(8) Perform the 0-20 Acceleration Test.
- Turn the fan On.
- Start the data logger for a few seconds before quickly depressing the throttle. The throttle is depressed at time "0".
- Run the vehicle past the 32 km/h (20 mph) before stopping the data log.
Note: The actual time for the vehicle to reach 32 km/h (20 mph) may be longer than the transmission performance report. The transmission performance report assumes a full throttle and the brakes locked.
Graph
Illustration 7 | g01500153 |
Torque converter stall test |
Illustration 8 | g01499113 |
Example of three torque converter stall tests with cooldown |
Power train Pro Report
Illustration 9 | g01447792 |
Example of a Powertrain Pro report from Caterpillar (1) Engine speed |
Engine stall speed (1) should be met within the seven seconds in order for the engine to meet the engine performance. Engine stall speed (1) should be met within 50 rpm.
SCAAN Report
Illustration 10 | g01449321 |
Example of a SCAAN report from Allison (2) Engine stall speed |
Engine stall speed (2) should be met within the seven seconds in order for the engine to meet the engine performance. Engine stall speed (2) should be met within 50 rpm.