AP-1000D, AP-1055D, AP-655C, BG-2255C, BG-2455D and BG-260D Asphalt Pavers Caterpillar

For the most accurate specifications for the sender, see the table "Resistor, Solenoid And Sender Specification". This table is located in the Electrical System Schematic for the machine that is being serviced.

Test Step 1. CHECK THE SENDER

1. Disconnect the sender from the machine harness.

2. Measure the resistance between the two contacts of the sender.

   The following data is the correct approximate resistance:

   196-3830 Fuel Level Sender for the AP-655C

   Empty tank ... 228 to 252 Ω

   Half tank ... 138 Ω

   Full tank ... 31 to 35 Ω

   235-8820 Fuel Level Sender for the AP-1000D and AP-1055D

   Empty tank ... 456 to 504 Ω

   Half tank ... 270 Ω

   Full tank ... 62 to 70 Ω

3. Actuate the sender by hand while you are measuring the resistance.

4. The resistance should change as the sender is actuated through the empty range to the full range.

Expected Result:

The resistance that is measured is within the specifications.

Results:

• OK - The resistance for the fuel level sender is correct. Proceed to test step 2.

• NOT OK - The resistance for the fuel level sender is NOT correct.

  Repair: Replace the fuel level sender.

  STOP

Test Step 2. CHECK IF THE DIAGNOSTIC CODE REMAINS

1. Clean the contacts of the harness connectors.

2. Reconnect all harness connectors.

3. Observe the status of the diagnostic code.

4. Operate the machine.

5. Observe the status of the diagnostic code.

Results:

• YES - The diagnostic code is NO longer active. The diagnostic code does not exist at this time. The initial diagnostic code may have been caused by a poor electrical connection that was corrected when a harness connector was disconnected and reconnected. Resume normal machine operationSTOP

• NO - The diagnostic code has not been corrected. The main display module has failed.

  Repair: Main display module failure is unlikely. Exit this diagnostic code and perform this diagnostic code again. Replace the main display module if the cause of the diagnostic code is not found. See Testing and Adjusting, "Main Display Module - Replace".

  STOP