DTC C2191/91: Vehicle Speed Signal Error (Test Mode DTC): Procedure

1. Turn the ignition switch off.
2. Connect a Techstream to the DLC3.
3. Turn the ignition switch to ON and the tester on.
4. Enter the following menus: Chassis / Tire Pressure Monitor / Data List
5. Check that the values indicated on the tester 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 tester and on the combination meter are the same.

NG → See step   2 

OK → See step   4 

1. Disconnect the E74 ECU connector.
   Fig 1: Inspecting Tire Pressure Warning ECU (SPD Signal)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Jack up the vehicle.
3. Move the shift lever to N.
4. Turn the ignition switch to ON.
5. Check the waveform of the ECU connector using an oscilloscope, while turning the wheel slowly.

   OK

   Tester Connection	Switch Condition	Specified Condition
   E74-2 (SPD) - E74-9 (GND)	Ignition switch ON	Correct waveform is as shown

   TOOL SETTING
   
   

   Item	Contents
   Tool Setting	2 V/DIV., 20 ms/DIV.
   Vehicle Condition	Rotate driving wheel slowly

   HINT: 

   • The wavelength becomes shorter as the vehicle speed increases.
   • Depending on the vehicle, the output waveform voltage may rise to 12 V if influenced by optionally installed systems.

NG → See step   3 

OK → See step   5 

1. Disconnect the E74 ECU connector.
   Fig 2: Checking Harness And Connector (Tire Pressure Warning ECU - Combination Meter)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the E13 meter connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   E74-2 (SPD) - E13-14 (+S)	Always	Below 1 Ω
   E74-2 (SPD) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   6