Reading and Clearing Diagnostic Trouble Codes
How to Troubleshoot the TPMS
System Indicator
The system has seven indicators.
- The low tire pressure indicator (A)
- The message indicator (B)
- The TPMS indicator (C)
- The right-front (RF) tire indicator (D)
- The left-front (LF) tire indicator (E)
- The right-rear (RR) tire indicator (F)
- The left-rear (LR) tire indicator (G)
The TPMS (tire pressure monitoring system) has seven indicators: four tire indicators (on the multi-information display), a low tire pressure indicator (LED indicator), a message indicator (LED indicator), and a TPMS indicator (on the multi-information display). When the TPMS control unit detects low pressure in a tire, or a problem in the system, it turns on, or blinks the appropriate indicator(s), as well as the message indicator.
The low tire pressure indicator
- If the system detects low tire pressure in any of the four tires, the low tire pressure indicator and the appropriate tire indicator(s) come on, as well as the message indicator.
- If the control unit detects a problem in the system during an indication of low tire pressure, it will turn off the tire indicator(s), store the DTC(s), and turn on the TPMS indicator and the low tire pressure indicator after blinking.
The TPMS indicator
- If a problem in the system is detected, the TPMS indicator come on, as well as the message indicator, and the low tire pressure indicator comes on after blinking for about 75 seconds.
- If low tire pressure and a problem in the system are detected, the TPMS indicator comes on, as well as the message indicator.
If the system is OK, the low tire pressure indicator should come on when you turn the ignition switch to ON (II), and then go off 2 seconds later. If it doesn't, there is a problem with the system.
If a problem is detected in the system, most DTCs will cause the TPMS indicator and the low tire pressure indicator (starts blinking) to come on and stay on until the system returns to normal. If DTC 45, 61, 63, 65, 67, 81, 83, or 85 is set, the TPMS indicator with the message indicator and the low tire pressure indicator will go off only when the ignition switch is turned to LOCK (0).
DTC 11, 13, 15, 17
If the system detects low tire pressure in any of the four tires, the low tire pressure indicator and the appropriate tire indicator(s) with the message indicator come on, and the TPMS control unit sets one or more of these codes: DTC 11, 13, 15, 17. When the tire pressure returns to normal, and TPMS control unit receives the normal pressure signal from, the tire pressure sensor, the TPMS control unit turns off the indicators.
Tire Pressure changing by Temperature
Tire pressures will increase slightly as the temperature in the tires rises during driving.
Pressures can also increase or decrease slightly with changes in outside air temperature. A temperature change of about 18 °F (10 °C) will change tire pressure by about 10 kPa (0.1 kgf/cm2, 1.5 psi). If the temperature drops, tire pressure could decrease enough to turn on the low tire pressure indicator and tire indicator(s), but later as tire temperature increases, the tire pressure could increase enough to turn them off. To resolve a complaint of such intermittent indications, confirm and clear the stored DTC(s) and check the tire pressures.
Then explain to the client how temperature changes can affect the system.
Problems That Are Not System Faults
- Tire Sealant
Fluid sealant used to repair a punctured tire can damage the tire pressure sensor mounted on each wheel. It can prevent the system from detecting the correct tire pressure, which sets a DTC 11, 13, 15, or 17 even though the system is normal.
- Cold Weather
When the weather is extremely cold, about -40 °F (-40 °C) or colder, the output of the lithium battery in each tire pressure sensor may drop far enough that the control unit sets a DTC for low battery voltage (31, 33, 35, or 37) even though the system is normal.
- Non-TPMS Wheels (including spare tire)
Vehicles equipped with TPMS must use wheels made for the system. Every TPMS wheel has an exclusive mark; do not use any other type of wheel. When the flat tire is taken out of the vehicle for repair, the TPMS indicator will come on (DTC 32, 34, 36, or 38) because the system is no longer receiving the signal from the tire's transmitter.
How a Diagnostic Trouble Code (DTC) is Set
- When the system detects a problem, the TPMS control unit sets a code, but shifts to fail-safe mode, and will not alert the driver to low tire pressures.
- If the TPMS control unit loses power, or fails, the TPMS indicator and the low tire pressure indicator (starts blinking) will come on, but no DTC will be set.
- The memory can hold all the DTCs that could possibly be set. However, when the same DTC is detected more than once, the most recent one overwrites the previous one, so only the latest DTC of each type is stored.
- DTCs are indicated in ascending order, not in the order they occurred.
- Set DTCs are stored in the EEPROM (nonvolatile memory), they cannot be cleared by disconnecting the battery. To clear a DTC, connect the HDS (Honda Diagnostic System) to the data link connector (DLC), and follow the screen prompts.
How to Troubleshoot DTCs
DTC troubleshooting procedures assume the cause of the problem is still present and the TPMS indicator and the low tire pressure indicator (starts blinking) are still on. Do not use a troubleshooting procedure unless the system has set the DTC listed for it.
NOTE: For DTCs 11, 13, 15, and 17 (tire low pressure), the TPMS indicator comes on and the low tire pressure indicator blinks only if the DTCs are caused by a system problem rather than low tire pressure.
1. Ask the client to describe the conditions when the indicators came on or blinked, and try to reproduce the same conditions for troubleshooting. Find out if the client checked and/or adjusted tire pressures since the indicator came on.
2. If an indicator does not come on during the test-drive, check for loose terminals, poor contact due to damaged terminals, etc. before you start troubleshooting.
3. After troubleshooting, clear the DTCs, and test-drive the vehicle. Make sure no indicators come on.
4. Check for other unit DTCs which are connected via F-CAN. If there are DTCs that are related to F-CAN, the most likely cause was that the ignition switch was turned to ON (II) with the TPMS control unit connector disconnected. Clear the DTCs. Check for PGM-FI and TPMS codes, and troubleshoot those first.
How to Retrieve DTCs
1. With the ignition switch LOCK (0), connect the HDS (Honda Diagnostic System) to the data link connector (DLC) (A) located under the driver's side of the dashboard.
2. Turn the ignition switch to ON (II).
3. Make sure the HDS communicates with the vehicle and the TPMS control unit. If it doesn't, troubleshoot the DLC circuit Testing and Inspection.
4. Follow the prompts on the HDS to display the DTC(s) on the screen. After determining the DTC, refer to the DTC Troubleshooting.
NOTE: See the HDS Help menu for specific instructions.
5. Turn the ignition switch to LOCK (0).
How to Clear DTCs
1. With the ignition switch in LOCK (0), connect the HDS to the data link connector (DLC) (A) located under the dash on the driver's side of the dashboard.
2. Turn the ignition switch to ON (II).
3. Make sure the HDS communicates with the vehicle and the TPMS control unit. If it doesn't, troubleshoot the DLC circuit Testing and Inspection.
4. Clear the DTC(s) by following the screen prompts on the HDS.
NOTE: See the HDS Help menu for specific instructions.
5. Turn the ignition switch to LOCK (0).