Fuel System & Emission Systems: Diagnosis Honda Accord VI

How to Use the PGM Tester or a Scan Tool

If the MIL (Malfunction Indicator Lamp) has come on

Scheme 2

Scheme 3

1. Start the engine and check the MIL.
2. If the MIL stays on, connect the Honda PGM Tester (A) or an OBDII scan tool to the Data Link Connector (DLC) (B) located under the driver's side of the dashboard.
3. Turn the ignition switch ON (II).
4. Check the Diagnostic Trouble Code (DTC) and note it. Then also check the freeze data. Refer to the DTC Troubleshooting Index and begin the appropriate troubleshooting procedure.

If the MIL did not come on

If the MIL did not come on but there is a driveability problem, refer to the Symptom Troubleshooting index in this section.

If you can't duplicate the DTC

Some of the troubleshooting in this section requires you to reset the ECM/PCM and try to duplicate the DTC. If the problem is intermittent and you can't duplicate the code, do not continue through the procedure. To do so will only result in confusion and, possibly, a needlessly replaced ECM/PCM.

How to End a Troubleshooting Session (required after any troubleshooting)

Note. The ECM/PCM is part of the immobilizer system. If you replace the ECM/PCM, it will have a different immobilizer code. In order for the engine to start, you must rewrite the immobilizer code with the Honda PGM Tester.

1. Reset the ECM/PCM as described above.
2. Turn the ignition switch OFF.
3. Disconnect the OBD II scan tool or Honda PGM Tester from the DLC.

How to Remove the ECM/PCM for Testing

If the inspection for a trouble code requires voltage or resistance checks at the ECM/PCM connectors, remove the ECM/PCM and test it

Scheme 4

1. Pull back the carpet from the passenger's and driver's side of the center console to expose the ECM/PCM.
2. Remove the two bolts (4 cylinder model), or three bolts V6 model) from the ECM/PCM (A).

How to Troubleshoot Circuits at the ECM/PCM

Special Tools Required

1. Digital Multimeter KS-AHM-32-003 (1) or a commercially available digital multimeter
2. Backprobe Set 07SAZ-001000A (2)

Scheme 5

1. Connect the backprobe adapters (A) to the stacking patch cords (B), and connect the cords to a multimeter (C).
2. Using the wire insulation as a guide for the contoured tip of the backprobe adapter, gently slide the tip into the connector from the wire side until it touches the end of the wire terminal.
3. If you cannot get to the wire side of the connector or the wire side is sealed (A), disconnect the connector and probe the terminals (B) from the terminal side. Do not force the probe into the connector.

Scheme 6

How to substitute the ECM/PCM for testing purposes

Use this procedure if you need a known-good ECM/PCM to test a vehicle. It allows you to swap an ECM/PCM from a "donor" vehicle without having to program it to the test vehicle's ignition key.

Scheme 7

1. Cut a temporary ignition key for the test vehicle with a non-immobilizer key blank.
2. Remove the ECM/PCM from the test vehicle.
3. Write the test vehicle's VIN on the ECM/PCM you just removed to avoid confusing it with the donor vehicle's ECM/PCM.
4. Remove the known-good ECM/PCM from the donor vehicle, and install it in the test vehicle.
5. Tape the donor vehicle's ignition key head-to-head to the test vehicle's temporary key (A). The ECM/PCM will recognize the code from the donor vehicle's key (B) and allow you to start the engine with the temporary key.
6. After completing your tests, reinstall both ECMs/PCMs, and destroy the temporary key.

Scheme 8

Scheme 9

Scheme 10

Symptom Troubleshooting Index

These symptoms DO NOT trigger Diagnostic Trouble Codes (DTCs) and cause the Malfunction Indicator Lamp (MIL) to come on. If the MIL is reported on, check for DTCs. If the vehicle has one of these symptoms, do the diagnostic procedure for it, in the sequence listed, until you find the cause.

Scheme 11

Self-diagnosis

When an abnormality occurs in the signal from a sensor, the ECM/PCM supplies ground for the Malfunction Indicator Lamp (MIL) and stores the Diagnostic Trouble Code (DTC) in erasable memory. When the ignition is first turned on, the ECM/PCM supplies ground to the MIL for 2 seconds ('98-01 models) or 15 to 20 seconds ('02 models) to check the MIL bulb condition.