CHECK WINDSHIELD WIPER RELAY ASSEMBLY (w/ Auto Wiper System)
Disconnect the H51 windshield wiper relay assembly connector.
Measure the voltage and resistance according to the value(s) in the table below.
| Terminal No. (Symbol) | Wiring Color | Terminal Description | Condition | Specified Condition |
|---|---|---|---|---|
| H51-2 (IG) - Body ground | L - Body ground | Engine switch on (IG) signal (Power source circuit) | Engine switch on (IG) | 11 to 14 V |
| Engine switch off | Below 1 V | |||
| H51-8 (VR2) - H51-21 (VR1) | B - W | Adjusting volume circuit | Windshield wiper switch adjusting lever* changed | 0 to 231 Ω |
| H51-12 (E) - Body ground | W-B - Body ground | Body ground | Always | Below 1 Ω |
| H51-16 (WIG) - Body ground | V - Body ground | Signal power source circuit | Engine switch on (IG) | 11 to 14 V |
| Engine switch off | Below 1 V | |||
| H51-25 (W) - Body ground | GR - Body ground | Front washer switch circuit | Front washer switch on | Below 1 Ω |
| Front washer switch off | 10 kΩ or higher |
Tech Tips
*: The rain sensor sensitivity can be adjusted by the windshield wiper switch adjusting lever.
If the result is not as specified, there may be a malfunction in the wire harness.
Reconnect the H51 windshield wiper relay assembly connector.
Measure the voltage and check for pulses according to the value(s) in the table below.
| Terminal No. (Symbol) | Wiring Color | Terminal Description | Condition | Specified Condition |
|---|---|---|---|---|
| H51-1 (+SM) - Body ground | B - Body ground | Front wiper motor position detection signal | Front wiper motor in low or high operation | Below 1 V ←→ 11 to 14 V |
| Front wiper motor off | Below 1 V | |||
| H51-3 (C1) - H51-5 (CO) | P - R | Front wiper switch AUTO signal circuit | Engine switch on (IG), front wiper switch in AUTO | Below 1 V |
| Engine switch on (IG), front wiper switch off | 11 to 14 V | |||
| H51-10 (+1) - Body ground | B - Body ground | Front wiper motor low speed signal circuit | Front wiper motor in low operation | 11 to 14 V |
| Front wiper motor off | Below 1 V | |||
| H51-11 (+2) - Body ground | V - Body ground | Front wiper motor high speed signal circuit | Front wiper motor in high operation | 11 to 14 V |
| Front wiper motor off | Below 1 V | |||
| H51-14 (MPX1) - Body ground | G - Body ground | Rain sensor signal | Engine switch on (IG) | Pulse generation |
| H51-24 (SPD) - Body ground | W - Body ground | Speed signal | Engine switch on (IG), wheel being rotated | Pulse generation (See Waveform 1) |
| H51-25 (W) - Body ground | GR - Body ground | Front washer switch circuit | Engine switch on (IG), front washer switch on | Below 1 V |
| Engine switch on (IG), front washer switch off | 11 to 14 V |
If the result is not as specified, the windshield wiper relay assembly may have a malfunction.
Waveform 1 (Reference):
| Item | Condition |
|---|---|
| Tool setting | 5 V/DIV., 20 ms./DIV. |
| Vehicle condition | Wheel being rotated |
Tech Tips
When the system is functioning normally, one wheel revolution generates 4 pulses. As the vehicle speed increases, the width indicated by (A) in the illustration narrows.