87214-ZY1-640 Honda MARK, ASSIST TILT (Honda Code 7215254).

Table 1
Diagnostic Trouble Codes for Excessive Soot Load
J1939 Code CDL Code Code Description
(code descriptions may vary) Comments
3719-16 E995 (2) DPF #1 Soot Loading Percent : High - moderate severity (2) The estimated soot load is above 116 percent.
Engine power is gradually derated as the soot load increases.
The warning lamp will flash.
3719-0 E995 (3) DPF #1 Soot Loading Percent : High - most severe (3) The estimated soot load is above 127 percent.
Engine power is derated 100 percent.
The stop lamp will come on.
7440-31 E1645 (1) Aftertreatment Active Regeneration Inhibited Due to Low Exhaust Pressure The exhaust gas pressure is too low to support DPF regeneration. The diagnostic codes listed in Table 1 can be caused by the following faults:
Faulty soot sensor system
Oil in the exhaust system
Faulty injectors
A mechanical fault in a cylinder
Low exhaust gas pressure
A faulty exhaust back pressure valve
A fault in the NOx Reduction System (NRS)
Fuel with a high sulfur content
Table 2
Required Tools
Tool Part Number Part Description Qty
A 366-7782 Attenuator 1 Engine operation must be kept to a minimum to minimize the amount of soot that is created. Follow the troubleshooting procedure to minimize the amount of engine operation.Complete the procedure in the order in which the steps are listed.
Table 3
Troubleshooting Test Steps Values Results
1. Check for Active Diagnostic Trouble Codes
A. Turn the keyswitch to the ON position.
B. Connect the electronic service tool.
C. Check for active diagnostic trouble codes.
Diagnostic trouble codes
Result: A 3719-xx code is active.
Proceed to Test Step 2.
Result: A 7440-31 code is active.
Proceed to Test Step 7.
Result: A code other than 3719-xx or 7440-31 is active.
Diagnose and rectify the fault before continuing with this procedure. Refer to Troubleshooting, "Diagnostic Trouble Codes".
2. Visually Inspect the Soot Sensor System
A. Inspect the coaxial cables between the soot sensor and the antennas for damage.
B. Make sure that the antenna connectors are correctly tightened to 1.2 N m (10.6 lb in).
Soot sensor
Result: The soot sensor cables are damaged.
Proceed to Test Step 3.
Result: The antenna connectors were loose.
Repair: Tighten the connectors to 1.2 N m (10.6 lb in)
Start the engine. Use the electronic service tool to perform the "Aftertreatment Regeneration System Test".
Stop the engine and check for a 3719–xx code.
If the 3719-xx code has been eliminated, proceed to Test Step 9.
If the 3719-xx code is still present, proceed to Test Step 3.
Result: No corrective actions were performed.
Proceed to Test Step 3.
3. Test the Soot Sensor System
A. Perform the "DPF Soot Loading Sensor Functional Test" on the electronic service tool by selecting the following menus:
"Diagnostics"
"Diagnostic Tests"
"DPF Soot Loading Sensor Functional Test"
Note: Tooling A will be required to perform the "DPF Soot Loading Sensor Functional Test".
C. Follow the instructions on the electronic service tool.
Soot sensor
Result: The "DPF Soot Loading Sensor Functional Test" fails.
Repair: Replace the soot sensor.
Use the electronic service tool to perform the "Aftertreatment Regeneration System Test". If necessary, diagnose any reported fault codes and then proceed to Test Step 9.
Result: The "DPF Soot Loading Sensor Functional Test" is successful.
Proceed to Test Step 4.
4. Check for Oil in the Exhaust System
A. Remove the flexible exhaust pipe. Refer to Disassembly and Assembly, "Flexible Exhaust Pipe - Remove and Install".
B. Inspect the exhaust system and Clean Emissions Module (CEM) inlet for oil deposits.
Exhaust system
Result: Oil deposits are present in the exhaust system.
Refer to Troubleshooting, "Exhaust System Contains Oil".
Result: No oil deposits are found in the exhaust system.
Proceed to Test Step 5.
5. Low Compression (Cylinder Pressure)
A. Perform a compression test. Refer to Systems Operation, Testing, and Adjusting, "Compression - Test".
Cylinder compression
Result: The results of the compression test are outside the specifications.
Repair: Investigate the cause and rectify any faults.
Note: Possible causes of low compression are shown in the following list:
Loose glow plugs
Faulty piston
Faulty piston rings
Worn cylinder bores
Worn valves
Faulty cylinder head gasket
Damaged cylinder head
Result: The results of the compression test are OK.
Proceed to Test Step 6.
6. Electronic Unit Injectors
A. Use the electronic service tool to perform the automatic "Cylinder Cutout Test". Refer to Troubleshooting, Service Tool Features for more information.
Note: If the compression test that was performed in Test Step 4 was satisfactory, the "Cylinder Cutout Test" will identify any faulty injectors.
Note: To make a judgment on the results from the "Cylinder Cutout Test", refer to Troubleshooting, Service Tool Features, 'Evaluating the "Automatic Cylinder Cutout Test" Fuel Measurements'.
Electronic Unit Injectors
Result: A faulty injector is indicated.
Repair: Remove any faulty electronic unit injectors. Refer to Disassembly and Assembly, "Electronic Unit Injector - Remove".
Install new electronic unit injectors. Refer to Disassembly and Assembly, "Electronic Unit Injector - Install".
Repeat the automatic "Cylinder Cutout Test". If the fault is still apparent, remove the replacement electronic unit injector and install the original electronic unit injector. Refer to Disassembly and Assembly, "Electronic Unit Injector - Remove" and Disassembly and Assembly, "Electronic Unit Injector - Install".
Result: All injectors are OK.
Proceed to Test Step 7.
7. Investigate Cause of 7440-31 Code
Note: Diagnostic code 7440-31 indicates that the exhaust gas pressure is too low to promote DPF regeneration.
A. Check the exhaust system from the engine to the CEM for gas leaks.
B. Check the sensors on the CEM for signs of gas leaks.
C. Check that the exhaust system insulation is correctly installed.
Diagnostic code
Result: Exhaust gas leaks are found in the exhaust system or the CEM.
Repair: Rectify the gas leak or make sure that the CEM sensors are correctly installed.
Proceed to Test Step 10.
Result: Exhaust system insulation is missing or damaged.
Repair: Repair the exhaust system insulation.
Proceed to Test Step 10.
Result: There are no exhaust gas leaks and the insulation is OK.
Proceed to Test Step 8.
8. Check the Exhaust Back Pressure Regulator and the NRS system
A. Use the electronic service tool to perform the "Air System Motor Valve Verification Test".
Pass
Result: The "Air System Motor Valve Verification Test" failed.
Repair: Troubleshoot active diagnostic codes generated as a result of the test.
Result: The "Air System Motor Valve Verification Test" passed.
Proceed to Test Step 9.