A/C - Poor A/C Performance Cooling Fans Inop
TECHNICALBulletin No.: 11-01-38-002
Date: June 24, 2011
Subject: Poor A/C Performance, Engine Cooling Fans Inoperative or Reduced Operation
Models:
2008-2011 Chevrolet Malibu (Excluding BAS Hybrid)
Condition
Some customers may comment on poor A/C cooling performance.
Further inspection may reveal the engine cooling fans to be inoperative or operating at a reduced speed.
Cause
This condition may be caused by increased resistance within the harness connector(s) at the underhood electrical center (UBEC). This increased resistance may reduce the effectiveness of the cooling fan circuit. The lack of air flow through the A/C condenser, caused by the inoperative cooling fans, may affect the condenser's ability to dissipate heat.
Correction
Use the following procedure to install a revised engine cooling fan relay harness.
Note
If the vehicle has a V6 engine, first check the 30 amp cooling fan fuse to determine if it is blown. If the fuse is blown, replace the fuse and proceed to step 10 to begin installation of the revised cooling fan relay harness.
1. Remove the battery box cover.
2. Disconnect the negative battery cable.
3. Remove the underhood electrical center (UBEC) cover.
4. Loosen the bolts securing the UBEC. Unlock the tabs and remove the UBEC.
5. In the illustration above, observe the orientation of the schematic for the fuse block. Identify the location of connectors X1 and X2.
6. Locate and mark for reference the following circuit terminals:
- Connector X1, Circuit 473, 0.35 D-BU, Pin B3, High Speed Cooling Fan Relay Control (LZ4 or LZE)
- Connector X1, Circuit 335, 0.35 D-GN, Pin F3, Low Speed Cooling Fan Relay Control (LY7 or LZ4 or LZE)
- Connector X1, Circuit 409, 3 L-BU, Pin E3, Cooling Fan Supply Voltage - Left
- Connector X1, Circuit 532, 3 GY, Pin A2, Cooling Fan Supply Voltage - Right
- Connector X1, Circuit 504, 3 WH, Pin B1, Cooling Fan Low Reference - Left
7. Locate and mark for reference the following circuit terminals:
- Connector X2, Circuit 473, 0.35 D-BU, Pin A11, High Speed Cooling Fan Relay Control (LY7 or LE5 or LE9)
- Connector X2, Circuit 335, 0.35 D-GN, Pin B10, Low Speed Cooling Fan Relay Control (LE5 or LE9)
8. Inspect the connector pins referenced above for evidence of overheating as shown.
- If evidence of overheating is observed, continue with this repair.
- If evidence of overheating is not observed, refer to published diagnostics in SI.
9. Remove all the cooling fan relays and fuses from the UBEC and discard.
10. Remove the front compartment sight shield.
11. Disconnect the cooling fan wire harness connectors. Secure the connectors to the existing harness using tape. These connectors will no longer be used.
12. Using the revised harness, P/N 22793482, position the cooling fan relay bracket onto the upper radiator support maintaining sufficient clearance from surrounding components. Mark the location of the holes in the bracket on the upper radiator support.
13. Drill the holes using a 3.5719 mm (9/64 in) drill bit. Secure the bracket and relay assembly to the upper radiator support using screws, P/N 15714277, or equivalent.
14. Route the cooling fan leads of the revised harness down to the cooling fans and connect the electrical connectors. Secure the harness to the cooling fan upper shroud using tie straps.
15. Route the Maxi-Fuse leads of the revised harness along the existing engine harness to the backside of the battery.
16. Remove the battery positive cable bolt from the UBEC. Install the Maxi-Fuse lead ring terminals to the bolt and reinstall.
17. Install the ground wire terminal of the revised harness to the existing G104 ground stud (1) as shown. G104 is located on the left side of the engine compartment, on the core support, between the left inflatable restraint front end sensor and G109.
18. Splice the cooling fan control leads of the revised harness to the engine control module (ECM).
1. Disconnect the appropriate ECM connector(s). Locate the low speed cooling fan relay control circuit 335 and the high speed cooling fan relay control circuit 473. Refer to the connector end views and circuit location table below.
2. Cut both of the cooling fan relay control circuits approximately 100 mm (4 in) from the connector.
3. Strip approximately 7.5 mm (0.313 in) of insulation from each of the four wires to be spliced.
Important
Use only Duraseal splice sleeves (salmon, P/N•12089189). Other splice sleeves may not protect the splice from moisture or provide a good electrical connection. Refer to Splicing Copper Wire Using Splice Sleeves in SI for splicing procedures.
4. Splice in the revised harness wires (Blue to Blue, Green to Green).
19. Install the front compartment sight shield.
20. Due to the added wires at the battery positive cable bolt, the UBEC cover will need to be modified. Cut out the section of the cover as shown in the above illustration.
21. Connect the negative battery cable.
22. Install the battery box cover.
X1 (LE5, LE9, LZ4, LZE) and X3 (LY7)
X1 (LY7)
Parts Information
Warranty Information
For vehicles repaired under warranty, use the table.
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