Wiring Harness: Testing and Inspection
WM 975249 Eliminating symptoms - Engine: Reworking wire harness (ground strap) for engine (Engine problems at high engine speeds and when starting the engine and/or catalytic converter damage/SY1710)
Tools
General information
Symptom
Information
These symptom-based repair instructions replace the instructions dated 16.08.2010.
Changes/additions compared to the previous instructions:
Information added under "Date of Introduction":
- Vehicle identification numbers for precise delimitation.
Information changed under "Working time":
- LO No. changed from 97875519 to 97524941 and 97524942.
Engine problems can occur or the engine may not start under certain driving and operating conditions (engine/engine compartment temperature very high, brief acceleration/tip in, starting the engine when the engine/engine compartment temperature is high).
This can happen without causing fault entries in the DME fault memory, but faults can be entered in some cases.
Engine problems can also damage the catalytic converter.
Cause, date of introduction and remedial action
Cause
The ground cable in the engine wire harness is too long. This causes electronic problems in DME and thus results in engine problems.
Date of introduction
An optimised engine wire harness is used in vehicles from 7 April 2010 onwards as of the vehicle identification numbers listed below:
Left-hand drive vehicles:
AA2 A7 2BL 011592 Panamera
AB2 A7 1AL 065526 Panamera S
97 ZAL 083583 Panamera Turbo
Right-hand drive vehicles:
97 ZBL 000273 Panamera
97 ZBL 000273 Panamera S
97 ZAL 083197 Panamera Turbo
Remedial action
In order to verify the problem, please ask your customer to describe the driving and operating conditions before and at the time the problem arose. The vehicle must then be test-driven under these conditions in order to implement the action required.
During the test drive, PIWIS Tester II 9818 and DSO test equipment (oscilloscope) are used to determine how the power supply for the engine components behaves while driving.
A second person is required in order to do this (to operate PIWIS Tester II).
Tools and materials
970.612.917.00 => Ground cable , repair kit
Press-out tool (commercially available), Press-out tool set Nr.155 Pos.1
Reworking wire harness (ground strap) for engine
Preliminary work
Information:
The specified working time does not include the working time required for the preliminary work described or the time required for test-driving the vehicle, if necessary.
1. Connect test equipment to PIWIS Tester II.
2. Connect test equipment to the fuse box.
2.1. Remove fuse 28 (-> 978409 Loosening and securing fuse box 978409 Loosening and securing fuse box) in the front left fuse box (passenger compartment).
2.2. Connect test equipment line CH1+ to the lower flat connector in the slot for fuse 28 ( => Figure 1 ).
Figure 1
2.3. Connect test equipment line CH1- to the positive jump-start terminal (term. 30) in the engine compartment ( -arrow- ).
Figure 2
Information
To achieve a verifiable result, only this connection point must be used for the measurement.
Line routing for test equipment line ( -dashed line- ):
Starting at the jump-start terminal, route the line along in the sealing profile area, past the gas-filled shock absorber hinge and engine cover hinge on the inside, over the slightly open door window to the DSO test equipment.
3. Connect PIWIS Tester II to the vehicle and switch it on.
3.1. Select => 'Diagnostics => 'Panamera' => 'Control unit selection'.
3.2. Press => F2 (Multimeter) => Go To.
3.3. Select => 'DSO'.
3.4. Adjust PIWIS Tester II display scaling:
Voltage: 0.5 V/div.
Time: 0.25 ms/div.
4. Perform a test drive.
During the test drive, the second person must check the PIWIS Tester II display.
4.1. If no problems are detected during the test drive and a voltage diagram similar to -left side of figure- is shown, it is not possible to conclusively determine a cause.
Finish the test drive and correct any faults that are present.
Re-insert fuse 28.
Figure 3
4.2. If the problem occurs during the test drive, but only a voltage diagram similar to -left side of figure- appears on the display:
Finish the test drive and correct any faults that are present.
Re-insert fuse 28.
4.3. If the problem occurs during the test drive and a voltage diagram similar to -right side of figure- appears on the display:
Finish the test drive and replace the ground strap for the engine as described below.
Re-insert fuse 28.
Reworking wire harness (ground strap) for engine
The following components must be removed and the connector/connection point X3 (tsx3) must be released from the engine wire harness
(rear right engine compartment):
- Remove DME control unit ( -item 1- ),
- Remove suction housing ( -item 2- ),
- Expose wire harness ( -item 3- ) and
- connector/connection point x3 ( -Pos. 4- ).
Figure 4
1. Remove DME control unit, see -> 247019 Removing and installing DME control unit - section on "Removing" 247019 Removing and installing DME control unit.
2. Remove suction housing for vehicle ventilation:
2.1. Remove blower in front right footwell, see -> 853019 Removing and installing heater/fresh-air blower motor - section on "Removing" Service and Repair.
2.2. Unscrew top screws on suction housing.
2.3. Release the inner clamps in the suction housing through the opening on the removed blower in the footwell.
2.4. Remove suction housing.
3. Carefully pull the released connector ( -arrow- ) out of the bracket, then release it and pull it apart.
Figure 5
4. In the lower part of the open connector, move the secondary lock on the connector to the side using a suitable small screwdriver in order to release it ( -arrows- ).
Figure 6
5. Release the brown ground cable in chamber four of the connector (see labelling on the connector, -arrow- ) using a suitable press-out tool ( => Figure 7 ).
Figure 7
Figure 8
6. Join the free end of the existing ground cable to the wire harness using insulating tape ( -arrow- ).
Figure 9
7. Slide the new ground cable (Part No.: 970.612.917.00) into chamber four of the connector until the locking lugs engage securely. Secure the other end to the direct ground point of the body ( => Figure 10 ).
Figure 10
8. In the lower part of the open connector, move the secondary lock on the connector to the side using a suitable small screwdriver in order to lock it ( -arrows- ).
Figure 11
Press both parts of the connector together and slide the connector into the bracket until it engages securely.
9. Install suction housing for vehicle ventilation:
9.1. Fit suction housing and tighten the top screws on the suction housing.
9.2. Lock the inner clamps in the suction housing through the opening on the removed blower in the footwell.
9.3. Install blower in front right footwell, see -> 853019 Removing and installing heater/fresh-air blower motor - section on "Installing" Service and Repair.
10. Install DME control unit, see -> 247019 Removing and installing DME control unit - section on "Installing" 247019 Removing and installing DME control unit.
End of remedial action.
Working time
97524941: Reworking wire harness for engine; Labor time 160 TU