For 1990-2009 cars

### Diagnostic Aids

Except for when it is in the Wash mode, the rear window wiper wipes the rear window at delay time intervals. With the rear wiper system activated, the length of time between wipes can be adjusted by selecting any one of the three delay speed settings of the windshield wiper switch. During the Wash mode, if the rear washer switch is momentarily turned to ON, the rear wiper will wipe the rear window 3-5 times and then park. However, if the rear washer switch is held to ON, the rear window wipers will continue to operate until the switch is released. While the delay speed of both the front and rear wipers is adjusted by the windshield wiper switch selections, the delay time intervals of the rear wiper are not synchronized with the delay time intervals of the front wipers. The rear wiper should stop at the Park position anytime the rear wiper is not wiping. However, if the ignition switch is turned OFF while the rear wiper is wiping, the wiper will stop at its current location on the glass.

### Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. This step will determine if the rear wiper operates properly when only the rear window washer switch is activated. When the rear window washer switch is operated with the rear wiper switch OFF, the rear wiper should wipe the window 3-5 times and then park.

1. This step helps to pinpoint the specific malfunction. The Park mode of the rear window wiper may be the only feature malfunctioning. When the rear wiper switch is ON, the rear wiper should stop at the parked position in between the timed strokes of the wiper. When the rear wiper switch is turned OFF, the rear wiper should park and remain in the parked position until either the wipe or wash mode is operated again.

Step | Action | Yes | No
--- | --- | --- | ---
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 |

1. Turn ON the ignition, with the engine OFF.
2. Turn the rear window wiper switch ON.

Does the rear window wiper operate?

Go to Step 3

Go to Step 5

3 |

1. Turn the rear window wiper switch OFF.
2. With the rear window wiper switch OFF, turn the rear window washer switch ON.

Does the rear window wiper operate?

Go to Step 4

Go to Step 7

4 | Important: Unless the rear window wiper is being operated for the Wash mode, it operates only in the delay modes.

• | When the rear wiper is ON, it should stop at the parked position in between timed strokes of the wiper.

• | When the rear wiper is turned OFF, it should park and remain in the parked position until either the wiper or wash mode is operated again.

Does the rear window wiper Park in the full down position as it should?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 9

5 | Turn the rear window washer switch ON. Does the rear window wiper operate? | Go to Step 8 | Go to Step 6
6 |

1. Turn OFF the ignition.
2. Remove the REAR WIPER Relay from the underhood fuse block.
3. Turn ON the ignition, with the engine OFF.
4. With a test lamp connected to a good ground, probe the accessory voltage feed circuit to the switch side of the relay at the underhood fuse block.

Does the test lamp illuminate?

Go to Step 10

Go to Step 20

7 |

1. Disconnect the body control module (BCM) J2 14 harness connector.
2. With a test lamp connected to ground, probe the rear window washer pump control circuit.
3. Operate the rear window washer switch to ON while the rear window wiper switch is OFF.

Does the test lamp illuminate?

Go to Step 17

Go to Step 13

8 |

1. Disconnect the BCM J2 14 harness connector.
2. With a test lamp connected to ground, probe the rear wiper switch signal circuit.
3. Operate the rear window wiper switch to ON.

Does the test lamp illuminate?

Go to Step 17

Go to Step 14

9 |

1. Turn OFF the ignition.
2. Disconnect the harness connector of the rear window wiper motor.
3. Turn ON the ignition, with the engine OFF.
4. With a test lamp connected to a good ground, probe the accessory voltage circuit of the rear window wiper motor.

Does the test lamp illuminate?

Go to Step 16

Go to Step 19

10 |

1. Turn OFF the ignition.
2. Connect a 3-amp fused jumper wire between the accessory voltage feed circuit terminal and the rear window wiper motor control circuit terminal at the underhood fuse block.
3. Turn the ignition ON, with the engine OFF.

Does the rear wiper operate?

Go to Step 24

Go to Step 11

11 |

1. Ensure that the fused jumper wire between the accessory voltage feed circuit terminal and the rear window wiper motor control circuit terminal is still connected.
2. With a test lamp connected to a good ground, probe the rear window wiper motor control circuit at the rear wiper motor.

Does the test lamp illuminate?

Go to Step 12

Go to Step 21

12 | Connect the test lamp between the rear window wiper motor control circuit and the rear window wiper motor ground circuit. Does the test lamp illuminate? | Go to Step 16 | Go to Step 18
13 | Test the rear window washer pump control circuit for an open or a high resistance. Did you find and correct the condition? | Go to Step 26 | Go to Step 15
14 | Test the rear wiper switch signal circuit for an open or a high resistance. Did you find and correct the condition? | Go to Step 26 | Go to Step 15
15 | Inspect for poor connections at the harness connector of the windshield wiper washer switch. Did you find and correct the condition? | Go to Step 26 | Go to Step 22
16 | Inspect for poor connections at the harness connector of the rear window wiper motor. Did you find and correct the condition? | Go to Step 26 | Go to Step 23
17 | Inspect for poor connections at the harness connector of the BCM. Did you find and correct the condition? | Go to Step 26 | Go to Step 25
18 | Repair the rear window wiper motor ground circuit for an open or a high resistance. Did you complete the repair? | Go to Step 26 | --
19 | Repair the accessory voltage circuit, between the REAR WIPER Relay splice and the wiper motor, for an open or a high resistance. Did you complete the repair? | Go to Step 26 | --
20 | Repair the open or high resistance in the accessory voltage feed circuit. Did you complete the repair? | Go to Step 26 | --
21 | Repair the open or high resistance in the rear window wiper motor control circuit. Did you complete the repair? | Go to Step 26 | --
22 | Replace the windshield wiper washer switch. Did you complete the replacement? | Go to Step 26 | --
23 | Replace the rear window wiper motor. Did you complete the replacement? | Go to Step 26 | --
24 | Replace the rear wiper relay. Did you complete the replacement? | Go to Step 26 | --
25 | Replace the body control module. Refer to Body Control Module Replacement . Did you find and correct the condition? | Go to Step 26 | --
26 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2