DESCRIPTION
The tire pressure warning ECU receives a vehicle speed signal from the combination meter. This DTC is stored upon entering signal check mode (test mode), and cleared when a vehicle speed signal of 20 km/h (12 mph) is detected for 3 seconds or more. This DTC is output only in signal check mode.
DTC No. |
DTC Detection Condition |
Trouble Area |
---|---|---|
C2191/91 |
Test mode procedure is performed |
|
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
PROCEDURE
1. |
READ VALUE USING TECHSTREAM (VEHICLE SPEED) |
(a) Turn the ignition switch off.
(b) Connect the Techstream to the DLC3.
(c) Turn the ignition switch to ON.
(d) Turn the Techstream on.
(e) Enter the following menus: Chassis / Tire Pressure Monitor / Data List.
(f) Check that the values indicated on the Techstream and on the combination meter are the same.
Tire Pressure Monitor
Tester Display |
Measurement Item/Range |
Normal Condition |
Diagnostic Note |
---|---|---|---|
Vehicle Speed |
Vehicle speed/ min.: 0 km/h (0 mph) max.: 255 km/h (158 mph) |
Almost same as actual vehicle speed |
Speed indicated on combination meter |
OK:
Vehicle speed indicated on the Techstream and on the combination meter are the same.
OK | ![]() |
USE SIMULATION METHOD TO CHECK |
|
2. |
INSPECT TIRE PRESSURE WARNING ECU (SPD SIGNAL) |
(a) Disconnect the D31 ECU connector. |
|
(b) Jack up the vehicle.
(c) Move the shift lever to N.
(d) Turn the ignition switch to ON.
(e) Check the waveform of the ECU connector using an oscilloscope while turning the wheel slowly.
OK:
Tester Connection |
Switch Condition |
Specified Condition |
---|---|---|
D31-2 (SPD) - D31-9 (GND) |
Ignition switch ON |
Correct waveform appears as shown |
*1 |
Rear view of wire harness connector (to Tire Pressure Warning ECU) |
Item |
Contents |
---|---|
Tool Setting |
5 V/DIV., 20 ms/DIV. |
Vehicle Condition |
Driving wheels rotating slowly |
HINT:
The wavelength becomes shorter as the vehicle speed increases.
OK | ![]() |
REPLACE TIRE PRESSURE WARNING ECU |
|
3. |
CHECK HARNESS AND CONNECTOR (ECU - COMBINATION METER) |
(a) Disconnect the D31 ECU connector. |
|
(b) Disconnect the E1 meter connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
Tester Connection |
Condition |
Specified Condition |
---|---|---|
D31-2 (SPD) - E1-16 (+S) |
Always |
Below 1 Ω |
D31-2 (SPD) - Body ground |
Always |
10 kΩ or higher |
*1 |
Front view of wire harness connector (to Tire Pressure Warning ECU) |
*2 |
Front view of wire harness connector (to Combination Meter) |
OK | ![]() |
REPLACE COMBINATION METER |
NG | ![]() |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
Problem Symptoms Table
PROBLEM SYMPTOMS TABLE
HINT:
Use the table below to help determine the cause of problem symptoms.
If multiple suspected areas are listed, the potential causes of the symptoms
are listed in order of probability in the "Suspected Area" ...
On-vehicle Inspection
ON-VEHICLE INSPECTION
CAUTION / NOTICE / HINT
CAUTION:
Be sure to follow the correct removal and installation procedures of the rear
airbag sensor.
PROCEDURE
1. INSPECT REAR AIRBAG SENSOR (VEHICLE NOT INVOLVED IN COLLISION)
(a) Perform a diagnostic sys ...
Low Power Supply Voltage (C1241/94)
DESCRIPTION
If a malfunction in the power source circuit occurs, or a malfunction in communication
with the skid control ECU or in a speed sensor occurs, the AWD control ECU will
prohibit operations by the fail-safe function.
DTC No.
...