TAC Tips Summer 2017

We are resolving a number of cases every day and wanted to share some of the great conversations and tips we’ve had from across the country. Follow-up on Twitter or Facebook for a regular update.

Contributor: ACDelco’s Daily TAC Tip comes from the team at ACDelco’s Technical Assistance Centre.


August 31, 2017
Thanks to our Program member from:     Mount Pearl, NL
Vehicle: 2013 Chevy Trax
Condition: DIC displays code 173
Agent recommendation: Recommend updating rear differential control module software to address this condition as per bulletin #PI1176A
Solution: Updated software for rear differential control module.

August 24, 2017
Thanks to our Program member from:     Lashburn, SK
Vehicle: 2003 GMC Sierra 5.3 L
Condition: DTC C0327. Encode was replaced but issue still exists. The range light does not work.
Agent recommendation: 
1. Check the encoder circuits at the transfer case for 5 V on the Light Green/Black (431) wire, ground on the Black/White (1554) wire, and a signal between 0.5-4.5 V on the Brown/White (1555) wire.
2. If any of the wiring is not agreed with the above-mentioned specifications, check for a wiring problem between the Transfer Case Control Module (TCCM) and the transfer case.
3. A scan tool can be used to monitor the signal voltage. If the Encoder Signal Voltage is going high, check the Encoder Low Reference circuit for an open or high resistance. If the encoder Signal Voltage is going low, check the 5 volt Reference and Encoder Signal circuits for an open or high resistance.
Solution: Broken wire around right front shock tower area.

August 17, 2017
Thanks to our Program member from:       Sarnia, ON
Vehicle: 2004 Pontiac Sunfire
Condition: IAC valve replaced and now vehicle surging and accelerating on its own.
Agent recommendation: Try a hard reset by disconnecting battery cables and touching negative and positive together for approximately 3 minutes.
Solution: Hard reset resolved issue.

August 10, 2017
Thanks to our Program member from:    Newcastle, ON
Vehicle: 2007 GMC Acadia
Condition:  Vehicle does not communicate with other modules when ECM is connected but is able to when ECM is disconnected. Grounds, power and communication lines are all good. 
Agent recommendation: Recommend trying to re-flash the ECM first.
Solution: Technician re-flashed ECM and communication issue was resolved.

August 3, 2017
Thanks to our Program member from:       Mount Pearl, NF
Vehicle: 2014 Ford Transit
Condition: The F65 Fuse blows intermittently. Rear lift gate does not operate when fuse is blown.
Agent recommendation: Check license plate bulbs and sockets for water entry and check the related connections for corrosion or water damage.
Solution: Replaced the license plate bulbs assembly because of water entry

July 27, 2017
Thanks to our Program member from:   Warburg, AB
Vehicle:  2015 GMC Acadia
Condition: Technician unable to clear DTC C0394 Rear Axle coupling solenoid temperature sensor.                                                                                                                                     
Solution: Temperature sensor built into rear axle module and module needs to be replaced.

July 20, 2017
Thanks to our Program member from:     Jonquiere, QC
Vehicle:  2010 Mini Cooper
Condition: Wiper motor not working, the inside fuse box (JBE) was replaced due to corrosion water intrusion.
Agent recommendation: Check at the motor for ground and power. Check that Transport Mode and JBE is properly coded.
Solution: JBE must be taken out of "Transport mode" and coded to VIN

July 13, 2017
Thanks to our Program member from:     Stevensville, ON
Vehicle: 2011 Ford F250 6.2L 
Condition: DTCs P0207 P0307 P0316. Technician replaced all spark plugs and 4 coils but only DTC P0307 comes back now but only on acceleration and not while idling.
Agent recommendation: check injector for possible issues.
Solution: Technician found a cracked injector.

July 6, 2017
Thanks to our Program member from:    Brampton, ON
Vehicle: 2009 Mercedes-Benz ML350
Condition: Driver door lock inoperative
Agent recommendation: With scan tool, read door open/close status in the Rear Signal Activation Module (SAM). With no issues on door status, activate door lock via scan tool through the Left/Right Front Door Control Unit. If operation fails to function actuator, suspect fault in Door Control Module, wiring, or actuator for the lock.
Solution: Drivers door actuator needed to be replaced.

June 29, 2017
Thanks to our Program member from:      Bow Island, AB
Vehicle: 2008 Chevrolet Silverado 5.3 
Condition: P0307 Exhaust valve moving but no intake valve movement and no compression
Agent recommendation: 
1. Remove the valve cover. 
2. Cranking the engine, check for rocker arm movement on the valves for cylinder 7. 
3. If one of the rocker arms is not moving, replace the corresponding lifter. 
4. If both rocker arms are not moving, it is possible the solenoid in the Valve Lifter Oil Manifold (VLOM) assembly may be stuck open or the bleed circuit may be plugged. Replace the VLOM. 
5. While apart (cylinder heads removed), inspect the Valve Lifter Guide for cracks and camshaft lobe wear. Reinsert the lifters into the Valve Lifter Guide. Attempt to rotate the lifters in the guide while looking for a crack in the guide
Solution: Replaced failed parts after conducting the process above.

June 22, 2017
Thanks to our Program member from:   St Thomas, ON
Vehicle:  2008 Chevrolet Impala
Condition: Customer replaced both 02 sensors in an attempt to pass emission test, but continued to fail.
Solution:  Clean injectors.  Technician flushed injectors 2 more times after he originally flushed them and was able to clear DTC and have vehicle pass emission test

June 15, 2017
Thanks to our Program member from:      Mount Pearl, NF
Vehicle:  2012 Ford F350
Enquiry:  Details on diagnostic procedure for DTC U0101 TCM.
Solution: Schematic used to find root cause - confirm TCM was defective. 

June 8, 2017
Thanks to our Program member from:     Windsor,ON
Vehicle: 2002 Dodge Dakota 
Question: How to adjust the timing after removal of distributor. The distributor was removed to repair a broken bolt under it. No reference mark can be found to install
Solution: Synchronize the distributor using scan tool.

June 1, 2017
Thanks to our Program member from:    Stittsville,ON
Vehicle: 2002 Ford Escape
Condition: Lift gate will not operate with remote or switch.
Agent recommendation: Check with scan tool if input from lift gate switch is showing a change when pressing the switch and if no try new SJB.
Solution: SJB module needs to be replaced and will order it from ACDelco.

TAC Information 

We’re listening! ACDelco’s TAC team listens because they know how frustrating it can be to get good sound advice when it comes to vehicle diagnostics.

It pays to get it done right, and fast - the first time!
That’s the objective for all of our ACDelco Technical Assistance Centre licensed technicians. To get your problem diagnosis dealt with quickly and correctly…and of course, to just be there to listen.

ACDelco Technical Assistance Centre – Diagnostic Hotline
Live Technical support via phone – available 60 hours a week!
Contact the ACDelco Info-Line for further details. 1-800-263-3526 prompt 2

The ACDelco TAC line is fully staffed with multi-lingual technicians Monday – Friday from 8am-6pm EST, ensuring they are available to take your call (or fax, or email). In English or French, our qualified TAC agents will be ready to answer your questions.

The TAC line uses the most advanced technology and current repair databases, in addition to detailed case information and data mining. Our agents have full access to common failure causes and repair procedures databases. Access to these cases can help solve the most complex requests.

Our TAC Specialists
ACDelco’s TAC line has master technicians supporting Domestic, European and Asian import vehicles. Agents have an impressive 45 years combined hands on experience. The breadth of experience includes:

  • Working directly with vehicle manufacturers and aftermarket suppliers
  • Class training delivery
  • Field experience
  • Auto body and collision repair
  • Heavy-duty and military powertrain experience. 

Daniel Bernard has 25 years of automotive technical experience both in the OE and aftermarket environments, as well as heavy duty trucks. His background includes technician, warranty administration, technical training, dealer tool development and validation, technical assistance center support. Daniel provides technical training and support services in French and English.

Daniel (Dan) Mariani has 21 years of automotive technical experience with experience in both the OE and aftermarket environments. He is Honda certified and holds certificates in Automotive Service, Mechanical – Tool & Die Maker, and Architectural Technology.

Systems Support
ACDelco’s TAC agents have a lengthy list of technical resources and databases to support your complex questions. This includes factory OE information, as well as internal technical experts, field engineers, product specialists, and technical writers for several OEM's.

Resource databases include all major all makes manufacturers. Additional repair databases include Alldata, IATN, Mitchell1, Automotive Service Profession, eSI and more.
Access to Service Technical Specialists include the following manufactures: GM, Mercedes Benz, VW, Audi, Ford, Lincoln, Mercury, Chrysler, BMW, Volvo, Honda, Nissan, SAAB, Toyota, Hyundai, & KIA.