Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 |
Important: Perform the following tests with the engine coolant at ambient temperature. Use a digital multimeter (DMM) at the coolant heater cord flat terminals in order to inspect the resistance of the entire coolant heater circuit. Is the reading higher than the specified value? | 45 ohms | Go to Step 2 | Go to Step 5 |
2 | Inspect the entire coolant heater cord. Is the coolant heater cord frayed, split or cut? | -- | Go to Step 9 | Go to Step 3 |
3 |
Are either of the coolant heater cord connector terminals loose or damaged? | -- | Go to Step 9 | Go to Step 4 |
4 | Use the DMM at the coolant heater terminals in order to inspect the resistance of the coolant heater. Is the reading higher than the specified value? | 43 ohms | Go to Step 10 | Go to Step 9 |
5 | Use the DMM at both of the coolant heater cord flat terminal and at the battery ground (negative) terminals in order to inspect the coolant heater circuit for a short to ground. Does the reading indicate a short to ground? | -- | Go to Step 6 | Go to Step 7 |
6 |
Does the reading indicate a short to engine ground? | -- | Go to Step 9 | Go to Step 8 |
7 |
Does the reading indicate an internal short? | -- | Go to Step 9 | Go to Step 8 |
8 | The tests indicate that the coolant heater and the coolant heater cord are OK. It is VERY unlikely, that the coolant heater has an internal short. Ensure that the coolant heater is plugged into a good power supply. It is also possible that a system fault may be intermittent. | -- | -- | -- |
9 | Replace the engine coolant heater cord. Refer to Coolant Heater Cord Replacement . Does the customer concern still exist? | -- | Go to Step 1 | System OK |
10 | Replace the engine coolant heater. Refer to Coolant Heater Replacement . Does the customer concern still exist? | -- | Go to Step 1 | System OK |
