For 1990-2009 cars

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Check the heating mat. Does the heating mat work? | -- | System OK | Go to Step 2
2 | Check the fuse F30. Is fuse F30 blown? | -- | Go to Step 3 | Go to Step 4
3 |

1. Check for a short circuit and repair it, if necessary.
2. Replace the fuse F30.

Is the repair complete?

--

System OK

--

4 | Use a voltmeter to check voltage at terminal 5 of each (left and right) heating mat switch. Does the voltmeter indicate the specified value? | 11-14 V | Go to Step 6 | Go to Step 5
5 | Repair the open circuit between the fuse F30 and the heating mat switch terminal 5. Is the repair complete? | -- | System OK | --
6 |

1. Turn the ignition switch ON.
2. Put the heating mat switch ON.
3. Use a voltmeter to check voltage at terminal 4 of each (left and right) heating mat switch.

Does the voltmeter indicate the specified value?

11-14 V

Go to Step 8

Go to Step 7

7 | Replace the heating mat switch. Is the repair complete? | -- | System OK | --
8 |

1. Turn the ignition switch ON.
2. Put the heating mat switch ON.
3. Use a voltmeter to check the voltage at the heating mat terminal 1.

Does the voltmeter indicate the specified value?

11-14 V

Go to Step 10

Go to Step 9

9 | Repair the open circuit between the left or right heating mat switch terminal 2 and the left or right heating mat terminal 1. Is the repair complete? | -- | System OK | --
10 |

1. Turn the ignition switch ON.
2. Put the heating mat switch ON.
3. Use a voltmeter to check the voltage at the terminal 2 of the heating mat.

Is the voltage indicate the specified value?

11-14 V

Go to Step 12

Go to Step 11

11 | Replace the left or right heating mat. Is the repair complete? | -- | System OK | --
12 | Replace the open ground circuit. Is the repair complete? | -- | System OK | --