CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY
Disconnect the I77 air conditioning amplifier assembly connector.
Measure the voltage and resistance according to the value(s) in the table below.
Tech Tips
Measure the values on the wire harness side with the connector disconnected.
| Tester Connection | Wiring Color | Terminal Description | Condition | Specified Condition |
|---|---|---|---|---|
| I77-1 (IG+) - I77-14 (GND) | B - W-B | Power source (IG) | Ignition switch ON | 11 to 14 V |
| I77-1 (IG+) - I77-14 (GND) | B - W-B | Power source (IG) | Ignition switch off | Below 1 V |
| I77-21 (B) - I77-14 (GND) | Y - W-B | ECU power supply | Always | 11 to 14 V |
| I77-14 (GND) - Body ground | W-B - Body ground | Ground | Always | Below 1 Ω |
If the result is not as specified, there may be a malfunction in the wire harness.
Reconnect the I77 air conditioning amplifier assembly connector.
Measure the voltage according to the value(s) in the table below.
| Tester Connection | Wiring Color | Terminal Description | Condition | Specified Condition |
|---|---|---|---|---|
| I77-38 (RDFG) - I77-14 (GND) | G - W-B*1 R - W-B*2 |
Mirror heater switch signal | Ignition switch ON, rear window defogger switch off | 11 to 14 V |
| I77-38 (RDFG) - I77-14 (GND) | G - W-B*1 R - W-B*2 |
Mirror heater switch signal | Ignition switch ON, rear window defogger switch on | Below 2.2 V |
| I77-37 (LIN1) - Body ground | V - Body ground | LIN communication signal | Ignition switch ON | Pulse generation |
*1: for LHD
*2: for RHD
If the result is not as specified, the air conditioning amplifier assembly may have a malfunction.
AIR CONDITIONING PANEL (HEATER CONTROL SWITCH BOARD)
Disconnect the I56 air conditioning panel (heater control switch board) connector.
Measure the voltage and resistance according to the value(s) in the table below.
Tech Tips
Measure the values on the wire harness side with the connector disconnected.
| Tester Connection | Wiring Color | Terminal Description | Condition | Specified Condition |
|---|---|---|---|---|
| I56-2 (IG+) - Body ground | R - Body ground | Ignition switch signal | Ignition switch ON | 11 to 14 V |
| I56-2 (IG+) - Body ground | R - Body ground | Ignition switch signal | Ignition switch OFF | Below 1 V |
| I56-6 (GND) - Body ground | W-B - Body ground | Ground | Always | Below 1 Ω |
If the result is not as specified, there may be a malfunction in the wire harness.
Reconnect the I56 air conditioning panel (heater control switch board) connector.
Check for pulses according to the value(s) in the table below.
| Tester Connection | Wiring Color | Terminal Description | Condition | Specified Condition |
|---|---|---|---|---|
| I56-9 (LIN1) - Body ground | V - Body ground | LIN communication signal | Ignition switch ON | Pulse generation |
If the result is not as specified, the air conditioning panel (heater control switch board) may have a malfunction.