BODY AS 4710780 - Caterpillar

Table 1
Diagnostic Trouble Codes
J1939 Code Code Description Comments
2659-2 Engine Exhaust Gas Recirculation 1 Mass Flow Rate : Erratic, Intermittent, or Incorrect The Electronic Control Module (ECM) will perform a check on the Exhaust Gas Recirculation (EGR) system when the engine is at normal operating temperature and low idle.
This diagnostic code will become active when the intake manifold pressure does not vary by at least 1 kPa (0.14 psi) when the EGR valve is operated over the full range.
The warning lamp will come on. Probable Causes
Diagnostic codes
Electrical connectors and harness
Air inlet and exhaust systemRecommended Actions
Note: The procedures have been listed in order of probability. Complete the procedures in order.
Table 2
Troubleshooting Test Steps Values Results
1. Diagnostic Codes
A. Connect the electronic service tool to the diagnostic connector. If necessary, refer to Troubleshooting, "Electronic Service Tools".
B. Turn the keyswitch to the ON position.
C. Use the electronic service tool to check for active or logged codes.
Diagnostic codes
Result: A diagnostic code for the EGR valve is active or logged.
Repair: Rectify the EGR valve code. Refer to Troubleshooting, "Diagnostic Trouble Codes".
Result: A 2659-2 diagnostic code is active.
Proceed to Test Step 2.
2. Inspect the Electrical Connectors and the Harness
A. Turn the keyswitch to the OFF position.
B. Inspect the connectors for the components in the EGR system. Refer to Troubleshooting, "Electrical Connector - Inspect".
C. Perform a 30 N (6.7 lb) pull test on each of the wires in any suspect connector and the connections at the ECM.
D. Check that the ground connection on the ECM and the negative terminal on the battery are correctly installed.
E. Check the ground connection on the ECM for abrasions and pinch points.
F. Check the harness for abrasion and pinch points from the EGR components to the ECM.
G. Check that any suspect connector is installed correctly.
Connectors and harness
Result: An electrical connector or a cable is not correctly installed.
Repair: Install the connector or cable correctly.
Result: The harness is faulty.
Repair: Install a replacement harness.
Result: The harness and connectors are OK.
Proceed to Test Step 3.
3. Check the Air Inlet and Exhaust System
A. Check the air inlet system for leaks and for restrictions.
B. Check the exhaust system for leaks and for restrictions.
Air inlet and exhaust system
Result: The air inlet system has a leak or is restricted.
Repair: Clear any restrictions in the air inlet system.
Repair any air leaks in the air inlet system.
Result: The exhaust system has a leak or is restricted.
Repair: Clear any restrictions in the exhaust system.
Repair any air leaks in the exhaust system.
If the fault is still present, contact the Dealer Solution Network (DSN).