Pinout Values and Diagnostic Parameters

A/C System Inspection at ECM

CAUTION:
- ECM connectors are waterproofed. Each terminal of the ECM connectors is sealed up with the grommet. Therefore, do not measure circuit voltage and resistance by inserting the tester's probe into the sealed terminal at the harness side. Or, ECM and its circuits may be damaged by water.
- ECM (PCM) cannot be checked by itself. It is strictly prohibited to connect voltmeter or ohmmeter to ECM (PCM) with couplers disconnected from it.

Voltage Check

ECM (PCM) and its circuits can be checked at ECM (PCM) wiring couplers by measuring voltage as follows. Refer to Inspection of ECM and Its Circuits.
- C37-26 Engine coolant temp. (ECT) sensor signal
- C37-39 Ground for ECM
- C37-48 A/C refrigerant pressure sensor signal
- C37-49 Output of 5 V power source
- C37-58 Ground for ECM
- C37-59 Ground for ECM
- C37-66 CMP sensor signal
- C37-67 Ground for sensors
- C37-73 Ground for ECM
- C37-80 Ground for ECM
- C37-81 Ground for ECM
- E23-3 Main power supply
- E23-9 CAN (high) communication line (active high signal) to ABS control module
- E23-14 Radiator fan relay No.3 output
- E23-15 Radiator fan relay No.1 output
- E23-17 CAN (low) communication line (active low signal) to ABS control module
- E23-23 Radiator fan relay No.2 output
- E23-37 A/C compressor relay output