How to Troubleshoot A/T Systems
How to Troubleshoot A/T Systems
How to Check for DTCs with the Honda Diagnostic System (HDS)
When the powertrain control module (PCM) senses an abnormality in the input or output system, the D indicator (A) in the gauge control module (B) will usually blink.
When the Honda Diagnostic System (HDS) is connected to the data link connector (DLC) (A) located behind the driver's dashboard lower cover, it will indicate the diagnostic trouble code (DTC) when the ignition switch is turned ON (II) and the appropriate menu is selected.
If the D indicator or the malfunction indicator lamp (MIL) has been reported on, or if a driveability problem is suspected, do this:
1. Connect the HDS to the DLC.
2. Turn the ignition switch to ON (II). Make sure the HDS communicates with the PCM. If it does not, go to the DLC circuit troubleshooting. Testing and Inspection
3. Select A/T system, and observe the DTC in the DTCs MENU on the HDS screen.
4. Record the freeze data and on-board snapshots for all fuel and emissions DTCs and A/T DTCs.
5. If there is a fuel and emissions DTC, first check the fuel and emissions system as indicated by the DTC.
6. Clear the DTC and data.
7. 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 indicated DTC's troubleshooting. 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 diagnostic 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, do the symptom troubleshooting. Check the list of probable cause(s) for the symptom, in the sequence listed, until you find the problem.
How to Check for DTCs with the SCS Mode (retrieving the flash codes)
NOTE: The preferred method is to use the HDS to retrieve the P-code.
When the PCM senses an abnormality in the input or output system, the D indicator (A) in the gauge control module (B) will usually blink.
When the D indicator has been reported on, connect the HDS to the DLC (A) located behind the driver's dashboard lower cover. Turn the ignition switch to ON (II), select SCS mode, then the D indicator will indicate flash the DTC.
If the D indicator and the MIL come on at the same time, or if a driveability problem is suspected, do this:
1. Connect the HDS to the DLC.
2. Turn the ignition switch to ON (II). Make sure the HDS communicates with the PCM. If it does not, go to the DLC circuit troubleshooting. Testing and Inspection
3. Select SCS mode, then observe the D indicator in the gauge control module. Codes 1 through 9 are indicated by individual short blinks. Code 10 and above are indicated by a series of long and short blinks. One long blink equals 10 short blinks. Add the long and short blinks together to determine the code.
4. Record all fuel and emissions DTCs and A/T DTCs.
5. If there is a fuel and emissions DTC, first check the fuel and emissions system as indicated by the DTC (except DTC 70 which means there is one or more A/T DTCs, and no problems were detected in the fuel and emissions circuit of the PCM).
6. Clear the DTC and data.
7. Drive the vehicle for several minutes under the same conditions as those indicated by the freeze data, and then recheck for DTC. If the A/T DTC returns, go to the indicated DTC's troubleshooting. 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.
How to Troubleshoot Circuits at the PCM Connectors
NOTE: The PCM overwrites data and monitors the EVAP system for about 40 minutes after the ignition switch is turned to LOCK (0). Jumping the SCS line after turning the ignition switch to LOCK (0) cancels this function. Disconnecting the PCM during this function, without jumping the SCS line first, can damage the PCM.
1. Jump the SCS line with the HDS.
2. Remove the PCM cover (A). Disconnect the PCM connectors (B), and probe the terminals from the terminal side of the connectors.
3. Check the connector terminal diameter, and select the suitable pin probe (male).
4. When diagnosis/troubleshooting is made at the PCM connector, use the measurement hole (A) above the terminal you need to check.
5. Connect one end of the patch cords (A) to a commercially available digital multimeter (B), and connect the other patch cord terminals to commercially available banana jacks (Pomona Electronics Tool No. 3563 or equivalent) (C).
6. Gently slide the pin probe (male) at the connector terminals from the terminal side. Do not force the tips into the terminals.
- For accurate results, always use the pin probe (male).
- To prevent damage to the connector terminals, do not insert test equipment probes, paper clips, or other substitutes as they can damage the terminals. Damaged terminals cause a poor connection and an incorrect measurement.
- Do not puncture the insulation on a wire. Punctures can cause poor or intermittent electrical connections.
Clear A/T DTCs Procedure
1. Connect the HDS to the DLC (A) located behind the driver's dashboard lower cover.
2. Turn the ignition switch to ON (II). Make sure the HDS communicates with the PCM. If it does not, go to the DLC circuit troubleshooting. Testing and Inspection
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 completed. The results of diagnostic tests for the DTC are displayed as:
- PASSED: The on-board diagnosis is successfully finished.
- FAILED: The on-board diagnosis has finished but failed.
- NOT COMPLETED: The on-board diagnosis was running but is out of the enable conditions of the DTC.
How to End a Troubleshooting Session
This procedure must be done after any troubleshooting.
1. Reset the PCM with the HDS while the engine is stopped.
2. Turn the ignition switch to LOCK (0).
3. Turn the ignition switch to ON (II), and wait for 30 seconds.
4. Turn the ignition switch to LOCK (0), and disconnect the HDS from the DLC.
5. Do the PCM idle learn procedure. PCM Idle Learn Procedure
6. Start the engine in P or N, and warm it 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 above 31 mph (50 km/h) or under the same conditions as those indicated by the freeze date.
Updating the A/T Software in the PCM
Refer to the PCM Update PCM Update when the A/T software updating is needed in the DTC troubleshooting.
Replacing the PCM
Refer to the PCM Replacement Service and Repair when replacing the PCM is needed in the DTC troubleshooting.
Substituting the PCM
Refer to the substituting the PCM. Initial Inspection and Diagnostic Overview
Failure Reproduction Technique
Be careful to the following points while the vehicle is raising on a lift for the test-drive.
- Disable the VSA by pressing the VSA OFF switch.
- VSA DTC's may be set when test-driving on a lift. If the VSA DTC(s) come on, clear the DTC(s) with the HDS.