Pinpoint additional heating tests

A1: FUSE CHECK F23

1 Enter the OFF position.

2 CHECK Fuse F23 (BJB).

• Is the fuse good?

→ Yes

Go to A2

→ No

REPLACE fuse F23 (20 A). CHECK the system is working properly. If the fuse blows again, LOCATE and REPAIR the short to ground using the wiring diagrams.

A2: CHECK THE VOLTAGE IN THE FUSE F23

1 Connect Fuse F23 (BJB).

2 Measure voltage between fuse F23 (20 A) and "mass".

• Is battery voltage being recorded?

→ Yes

Go to A3

→ No

RESTORE power to fuse F23 using the wiring diagrams. CHECK the system is working properly.

A3: FUSE CHECK F28

1 CHECK Fuse F28 (BJB).

• Is the fuse good?

→ Yes

Go to A4

→ No

REPLACE fuse F28 (10 A). CHECK the system is working properly. If the fuse blows again, LOCATE and REPAIR the short to ground using the wiring diagrams.

A4: FUSE VOLTAGE CHECK F28

1 Connect Fuse F28 (BJB).

2 Drive the ON position.

3 Measure voltage between fuse F28 (10 A) and "mass".

• Is battery voltage being recorded?

→ Yes

Go to A5

→ No

RESTORE power to fuse F28 using the wiring diagrams. CHECK the system is working properly.

A5: VOLTAGE CHECK IN AUXILIARY HEATER

1 Enter the OFF position.

2 Disconnect the C878 auxiliary heater.

3 Measure the voltage between connector C878, pin 1, auxiliary heater circuit 30-RD18 (red), from the wiring harness side, and ground.

• Is battery voltage being recorded?

→ Yes

Go to A6

→ No

LOCATE and REPAIR the open circuit between the auxiliary heater and fuse F23 using the wiring diagrams. CHECK the system is working properly.

A6: AUXILIARY HEATER VOLTAGE CHECK

1 Drive the ON position.

2 Measure the voltage between pin 4 of auxiliary heater connector C878, circuit 15-RD18 (green-red), from the wiring harness side, and ground.

• Is battery voltage being recorded?

→ Yes

Go to A7

→ No

LOCATE and REPAIR the open circuit between the auxiliary heater and S117 solder joint using the wiring diagrams. CHECK the system is working properly.

A7: CHECK THE CONTROL VOLTAGE IN THE AUXILIARY HEATER

NOTE: Use appropriate methods to cool down the outside temperature sensor to at least 5°C.

1 Drive the START position.

2 Measure the voltage between pin 5 of auxiliary heater connector C878, circuit 64S-RD18 (white-blue), from the wiring harness side, and ground.

• Is battery voltage being recorded?

→ Yes

Go to A8

→ No

Go to A9

A8: AUXILIARY HEATER GROUND CIRCUIT CHECK

1 Enter the OFF position.

2 Measure the resistance between pin 2 of auxiliary heater connector C878, circuit 31-RD18 (black), from the wiring harness side, and ground.

• Is the resistance less than 2 ohms?

→ Yes

CHECK and if necessary REPLACE the auxiliary heater. CHECK the system is working properly.

→ No

LOCATE and REPAIR the open circuit between the auxiliary heater and ground point G37 using the wiring diagrams. CHECK the system is working properly.

A9: OUTDOOR TEMPERATURE SENSOR VOLTAGE CHECK

1 Enter the OFF position.

2 Disconnect the C875 outside temperature sensor.

3 Drive the START position.

4 Measure the voltage between pin 1 of connector C875, outdoor temperature sensor, circuit 64-RD18 (white-blue), from the wiring harness side, and ground.

• Is battery voltage being recorded?

→ Yes

Go to A10

→ No

Go to A11

A10: CHECK THE ELECTRICAL CIRCUIT BETWEEN THE OUTSIDE TEMPERATURE SENSOR AND THE AMPLIFIER HEATER FOR AN OPEN

1 Enter the OFF position.

2 Measure the resistance between pin 2 of connector C875, outdoor temperature sensor, circuit 64S-RD18 (white-blue), on the wiring harness side, and pin 5 of auxiliary heater connector 878, circuit 64S-RD18 (white-blue), from the wiring harness side.

• Is the resistance less than 2 ohms?

→ Yes

REPLACE the outside temperature sensor. CHECK the system is working properly.

→ No

LOCATE and REPAIR open circuit 64S-RD18 (white-blue) between the outside temperature sensor and the booster heater using the wiring diagrams. CHECK the system is working properly.

A11: VOLTAGE CHECK IN ENGINE RUN RELAY

1 Enter the OFF position.

2 Disconnect C1013 Engine Run Relay (BJB).

3 Drive the ON position.

4 Measure the voltage between pin 3 of connector C1013, engine run relay circuit 15-PA20 (green-orange), from the wiring harness side, and ground.

• Is battery voltage being recorded?

→ Yes

Go to A12

→ No

LOCATE and REPAIR open circuit 15-PA20 (green-orange) between the engine run relay and fuse F28, using the wiring diagrams. CHECK the system is working properly.

A12: CHECK THE CONTROL VOLTAGE IN THE ENGINE RUN RELAY

1 Measure the voltage between pin 1 of connector C1013 engine run relay circuit 15-PA19 (black and green), from the wiring harness side, and ground.

• Is battery voltage being recorded?

→ Yes

Go to A13

→ No

LOCATE and REPAIR the open circuit between the engine run relay and solder joint S117 using the wiring diagrams. CHECK the system is working properly.

A13: CHECK ENGINE RUN RELAY GROUND ELECTRICAL CIRCUIT

CAUTION: A test lamp rated at 12V and rated at 1.2W must be used when performing the following test. Otherwise, the PCM may be damaged or the test will give incorrect results.

NOTE: Make sure the generator is working properly before taking the next measurement.

1 Drive the START position.

2 Use a test lamp to check the voltage between pins 1 and 2 of connector C1013 of the engine run relay (12 V, 1.2 W).

• Is the indicator lamp on?

→ Yes

Go to A14

→ No

Vehicles with 104-pin EEC: Go to A15

Vehicles with 121-pin EEC: Go to A16

A14: CHECK THE ELECTRICAL CIRCUIT BETWEEN ENGINE RUN RELAY AND OUTSIDE TEMPERATURE SENSOR FOR OPEN

1 Enter the OFF position.

2 Measure the resistance between pin 1 of connector C1013 engine run relay circuit 64-PA20 (yellow-blue), on the wiring harness side, and pin 1 C875 of the outdoor temperature sensor connector, circuit 64-RD18 (white-blue), from the wiring harness side.

• Is the resistance less than 2 ohms?

→ Yes

REPLACE engine run relay. CHECK the system is working properly.

→ No

LOCATE and REPAIR the open circuit between the engine run relay and the outside temperature sensor using the wiring diagrams. CHECK the system is working properly.

A15: CHECK THE ELECTRICAL CIRCUIT BETWEEN THE ENGINE RUN RELAY AND THE POWER PACK CONTROL MODULE (PCM) FOR A BREAK

1 Enter the OFF position.

2 Disconnect the C415 PCM.

3 Measure the resistance between C1013 Engine Run Relay Pin 2, harness side, and C415 PCM Pin 6, circuit 31S-PA19 (black and green), from the wiring harness side.

• Is the resistance less than 2 ohms?

→ Yes

CHECK and REPLACE PCM if necessary. CHECK the system is working properly.

→ No

LOCATE and REPAIR the open circuit between the engine run relay and the PCM using the wiring diagrams. CHECK the system is working properly.

A16: CHECK THE ELECTRICAL CIRCUIT BETWEEN THE ENGINE RUN RELAY AND THE POWER PACK CONTROL MODULE (PCM) FOR A BREAK

1 Enter the OFF position.

2 Disconnect the C414 PCM.

3 Measure the resistance between C1013 engine run relay connector pin 2, harness side, and C414 PCM connector pin 23, circuit 31S-PA19 (black and green), from the wiring harness side.

• Is the resistance less than 2 ohms?

→ Yes

CHECK and REPLACE PCM if necessary. CHECK the system is working properly.

→ No

LOCATE and REPAIR the open circuit between the engine run relay and the PCM using the wiring diagrams. CHECK the system is working properly.