How to Troubleshoot A/T Systems

How to Check for DTCs with the Honda Diagnostic System


When the powertrain control module (PCM) senses an abnormality in the input or output systems, the D indicator (A) in the gauge assembly (B) will usually blink.

 

When the Honda diagnostic system (HDS) is connected to the data link connector (DLC) (A) (located under the left end of the dash), it will indicate the diagnostic trouble code (DTC) when the ignition switch is turned ON (II).

 

If the D indicator or malfunction indicator lamp (MIL) has been reported on, or if a driveability problem is suspected, follow this procedure:

1.Connect the HDS to the DLC. (See the HDS user's manual for specific instructions.)

2.Turn the ignition switch ON (II), select A/T system and observe the DTC in the DTCs MENU on the tester screen.

3.Record all fuel and emissions DTCs, A/T DTCs, and freeze data.

4.If there is a fuel and emissions DTC, first check the fuel and emissions system as indicated by the DTC (except for DTC P0700, DTC P0700 means there is one or more A/T DTCs, and no problems were detected in the fuel and emissions circuit of the PCM).

5.Clear the DTC and data.

6.Drive the vehicle for several minutes under the same conditions as those indicated by the freeze data, and then recheck for a DTC. If the A/T DTC returns, go to the DTC troubleshooting Index. If the DTC does not return, there was an intermittent problem within the circuit. Make sure all pins and terminals in the circuit are tight.

Symptom Troubleshooting Versus DTC Troubleshooting


Some symptoms will not trigger diagnosis trouble codes (DTCs) or cause the D indicator to blink. If the malfunction indicator lamp (MIL) was reported ON or the D indicator has been blinking, check for DTCs. If the vehicle has an abnormal symptom, and there are no DTCs stored, go to the Symptom Troubleshooting Index. Check the list of probable cause(s) for the symptom in the sequence listed, until you find the problem.

How to Troubleshoot Circuits at the PCM


1.Remove the glove box stops, then bring the glove box down.

2.Loosen the mounting nut (A) on the lower portion of the PCM (B), and remove the mounting bolt (C) and nut (D).

NOTE: The illustration shows LHD model; RHD is symmetrical.

 

3.Lift the PCM up to clear the mounting nut on the lower portion of the PCM, then pull out the PCM.

4.Inspect the circuit on the PCM, according to the DTC troubleshooting with a digital multitester (A) and tapered tip probe (B) as shown.

 

5.If you cannot get to the wire side of the connector or the wire side is sealed, disconnect the connector and use the tester probe to probe the connectors from the terminal side. Do not force the probe into the connector.

Clear A/T DTCs, and PCM Reset Procedures


1.Connect the HDS to the DLC.

2.Turn the ignition switch ON (II).

3.Clear the DTC(s) on the HDS screen.

OBD Status


The OBD Status shows the current system status of each DTC and all of the parameters. This function is used to see if the technician's repair was successfully finished. The results of diagnostic tests for the DTC are displayed as:

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 PCM in a troubleshooting procedure. Update the PCM only if the PCM does not have the latest software loaded.

Do not turn the ignition switch OFF while updating the PCM. If you turn the ignition switch OFF, the PCM can be damaged.

How to Update the PCM


NOTE:

1.Turn the ignition switch ON (II). Do not start the engine.

2.Connect the Honda interface module (HIM) to the DLC located under the left end of the dash.

3.Update the PCM according to the procedures described on the HIM label. If the software in the PCM is the latest, replace the PCM.

How to Substitute the PCM


1.Connect the HDS to the DLC.

2.Turn the ignition switch OFF.

3.Jump the SCS line with the HDS.

4.Remove the PCM, and install a known-good PCM.

5.Rewrite the immobilizer code with the PCM replacement procedure in the HDS; this will allow you to start the engine.

6.After completing your test, reinstall the original PCM, and rewrite the immobilizer code with the PCM replacement procedure in the HDS again.

How to Remove and Install the PCM


1.Connect the HDS to the DLC.

2.Turn the ignition switch OFF.

3.Jump the SCS line with the HDS.

4.Disconnect PCM connectors.

5.Remove the harness connector, and open the glove box.

6.Remove the harness connector clamp (A) from its bracket.

 

7.Loosen the mounting nut (B) on the lower right of the PCM, and remove the mounting bolt (C) and nut (D) on the left of the PCM.

8.Lift the PCM up to clear the mounting nut on the lower right of the PCM, and pull out the PCM (E).

9.Install the PCM in the reverse order of the removal.

How to End a Troubleshooting Session


This procedure must be done after any troubleshooting.

1.Turn the ignition switch OFF.

2.Connect the HDS to the DLC.

3.Turn the ignition switch ON (II).

4.Clear the DTC(s) on the HDS screen.

5.Turn the ignition switch ON (II).

6.Start the engine in the P or N position, and warm it up to normal operating temperature (the radiator fan comes on).

7.To verify that the problem is repaired, test-drive the vehicle for several minutes at speeds over 50 km/h (30 mph) or in freeze data range.