Fuel & Emission Systems: Diagnosis Honda CR-V II

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.

Reset the ECM/PCM with the Scan Tool or the HDS

1. Turn the ignition switch ON (II). Do not start the engine.
2. Use the scan tool or the HDS to clear the DTC. NOTE: For the specific operations, refer to the user's manual that came with the scan tool or the HDS.

Scheme 2

1. Turn the ignition switch OFF.
2. Remove the No. 6 ECU (ECM/PCM) (15A) fuse (A) from the under-hood fuse/relay box (B) for 10 seconds.

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

1. Reset the ECM/PCM as described above.
2. Do the ECM/PCM idle learn procedure (see «ECM/PCM IDLE LEARN PROCEDURE»(ref-171388-S26374727982005020300000) ).
3. Turn the ignition switch OFF.
4. Disconnect the scan tool or the HDS from the DLC. NOTE: The ECM/PCM is part of the immobilizer system. If you replace the ECM/PCM, it will have a different immobilizer code. To start the engine, you must rewrite the immobilizer code with the HDS.

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 3

1. Disconnect the negative cable from the battery.
2. Remove glove box (see «GLOVE BOX REMOVAL/INSTALLATION»(ref-171400-S28468941812005020300000) ).
3. Disconnect the gray 20P ECM/PCM wire harness connector, and remove it from the ECM/PCM mounting bracket. Disconnect the 7P mode control motor connector. Remove PGM-FI main relay 2 (A). Remove the ECM/PCM mounting bolt (B) and the bracket.
4. Remove the nuts, then remove the ECM/PCM (C).
5. Install the ECM/PCM in the reverse order of removal.
6. Reconnect the negative cable to the battery.
7. Do the ECM/PCM idle learn procedure (see «ECM/PCM IDLE LEARN PROCEDURE»(ref-171388-S26374727982005020300000) ).

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 4

1. Connect the backprobe adapters (A) to the stacking patch cords (B), and connect the cords to a digital 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.

Note. Do not puncture the insulation on a wire. Punctures can cause poor or intermittent electrical connections.

Scheme 5

ECM/PCM Updating and Substitution for Testing

Special Tools Required

Honda Interface Module (HIM) EQS05A35570

Use this procedure when you have to substitute a known-good ECM/PCM in a troubleshooting procedure. Update the ECM/PCM only if the ECM/PCM does not already have the latest software loaded.

Note. Do not turn the ignition switch OFF while updating; the ECM/PCM can be damaged.

Symptom Troubleshooting Index

When the vehicle has one of these symptoms, check for a diagnostic trouble code (DTC) with the scan tool. If there is no DTC, do the diagnostic procedure for the symptom, in the sequence listed, until you find the cause.

Scheme 6

Scheme 7

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 15 to 20 seconds to check the MIL bulb condition. If all readiness code are not set, the MIL will flash five times. If readiness code are set to complete, the MIL will go out. The MIL may be turned off by the ECM/PCM if the problem that originally caused the MIL to be illuminated is a intermittent one.

When the Scan Tool is used

1. Connect the scan tool to the vehicle's data link connector (DLC), and bring up the tool's generic OBD II mode.
2. Start the engine.
3. Test-drive the vehicle under stop-and-go conditions with short periods of steady cruise. After about 5 miles (4.0 km), the readiness code should switch from incomplete to complete.
4. If the readiness code is still set to incomplete, check for a temporary DTC. If there is no DTC, one or more of the enable criteria were probably not met; repeat the procedure.

1. Connect the scan tool to the vehicle's data link connector (DLC), and bring up the tool's generic OBD II mode.
2. Start the engine.
3. Test-drive the vehicle under stop-and-go conditions with short periods of steady cruise. During the drive, decelerate (with the throttle fully closed) for 5 seconds. After about 3.5 miles (5.6 km), the readiness code should switch from incomplete to complete.
4. If the readiness code is still set to incomplete, check for a temporary DTC. If there is no DTC, the enable criteria was probably not met; repeat the procedure.