Coolant Pump - (Auxiliary) Retrofit Procedure
Date: November 1998Order No: P-SI-MBNA-83.70/54
Supersedes:
Group: 83
SUBJECT:
MODEL 170
RETROFITTING AUXILIARY COOLANT PUMP INSTALLATION
This bulletin concerns early production model 170 vehicles without an auxiliary coolant pump. Adding an auxiliary coolant pump resolves air outlet temperature fluctuation conditions during stop and go driving. Following is the installation procedure for the auxiliary coolant pump.
INSTALLATION PROCEDURE
1. Record the customer's pre-set radio frequency selections.
2. Disconnect and cover the ground lead from the battery.
3. Remove the air cleaner housing to expose the front of the right wheelhouse.
4. Remove the hose between the T-fitting at the duo-value (Y21) and the engine (Figure 1).
5. Remove the wiring harness clip from the front of the right wheelhouse (Figure 2).
6. Photocopy and cut out the template in this bulletin.
7. Align A and B of the template with A and B (Figure 3), of the right wheelhouse.
8. Use a center punch to mark C and D of the template onto the right wheelhouse.
9. Drill a 3 mm hole at points C and D (Figure 3), of the wheelhouse.
10. Reinsert the wiring harness clip.
11. Mount the auxiliary coolant pump/bracket assembly (M13/2) to the newly drilled holes with the two supplied sheet metal screws, (Figure 4).
12. Install the supplied hose between the auxiliary coolant pump and the T-fitting at duo-valve.
13. Install the supplied hose between the auxiliary coolant pump and the engine.
14. Remove the A/C pushbutton control module (N19). (See WIS: AR83.25-P-1120G).
15. Remove the engine control module (ECM) (N3/4) (See WIS: AR54.20-P-1257-01 C)).
16. Route a 200 cm long brown/green (BN/GN) 0.5 mm wire from the auxiliary coolant pump location, into the control module box entering through the main engine harness access hole, and exiting through the engine compartment bulkhead access hole into the A/C pushbutton control module location (Figure 5).
17. Install the supplied pin at the A/C pushbutton control module end of the BN/GN wire.
18. Disassemble the electrical connector for the A/C pushbutton control module, and insert the BN/GN wire pin in pin connector location # 8 (Figure 6).
19. Reassemble the A/C pushbutton control module electrical connector.
20. Reinstall the A/C pushbutton control module.
21. Reinstall the ECM.
Note:
Current 170 model A/C pushbutton control modules have a Residual Heating feature. Old and new version modules are interchangeable and the auxiliary coolant pump will operate with either module.
22. Route a 100 cm long red/yellow 0.5 mm wire from the auxiliary coolant pump location to the duo-valve location.
23. Wrap the RD/YE and BN/GN wires together with electrical tape, and secure them to the existing wiring harness at the right wheelhouse with wire ties (Figure 7).
24. Disconnect and disassemble the duo-valve electrical connector.
25. Solder the RD/YE wire end to the existing RD/YE wire at pin connector location # 2 of the duo-valve electrical connector (Figure 8).
26. Reassemble and reconnect the duo-valve electrical connector.
27. Solder the two supplied terminals to the auxiliary coolant pump end of the BN/GN and RD/YE wires.
28. Install the RD/YL wire terminal into terminal 1 and the BN/GN wire into terminal 2 of the supplied electrical connector housing (Figure 9).
29. Connect the auxiliary coolant pump electrical connector.
30. Reconnect the ground lead to the battery.
31. Enter the radio code, then reprogram the customer's pre-set radio frequency selections.
32. Make sure all electrical connections are good.
33. Run the engine to operating temperature, then bleed the coolant system.
34. Inspect for coolant leaks and replenish any lost coolant.
35. Use the Hand-Held Tester (HHT) to version code: "Auxiliary Coolant Pump - Yes".
Note:
Use model 210 or 202 Tempmatic version if this screen is not available on the current HHT module for model 170.
36. Operate the heating system to verify that the auxiliary coolant pump is functioning properly.
Parts Information
In Case of Warranty