Welcome, Guest. Please login or register.
April 20, 2018, 02:42:20 am

Login with username, password and session length
435157 Posts in 37249 Topics by 9534 Members
Latest Member: 88_GT
Search: Advanced search
Advertiser Inquiries
+ SBFTECH.com Experienced Small Block Ford Tech
|-+ General Tech
| |-+ Joel 5.0's Electronic Engine Management
| | |-+ EEC_IV Troubleshooting Procedures
| | | |-+ NSS/Clutch Pedal Switch Code 67 Troubleshooting
0 Members and 1 Guest are viewing this topic. « previous next »
Pages: [1] Go Down Print
Author Topic: NSS/Clutch Pedal Switch Code 67 Troubleshooting  (Read 8844 times)
Joel5.0
El Hombre
Administrator
Big Block
*****
Offline Offline

Posts: 22510


Location: Puerto Rico
Miracles?.... by appointment only!


« on: March 19, 2011, 06:10:10 pm »

NSS/Clutch Pedal Switch Code 67 Troubleshooting

Codes Definitions:

67 - Park Neutral Position Switch Circuit Open; A/C On -Manual (O), Manual Lever Position Sensor Out Of Range/A/C On (CM,O), Clutch Switch Circuit Failure (CM)

Clutch Pedal Switch, T5 Transmission Gear Switch & Auto Trans. Neutral Switc





Background Information and Previous Misconceptions

The neutral safety circuit for manual tranny setups, is comprised by two switches, clutch sense switch and a gear/neutral safety switch on the tranny, setup in a parallel circuit as shown below. The clutch sense switch is open pedal up, and the gear switch is open in any gear other than neutral. None of these switches is used in the starting circuit to activate the starter, they simply "inform" the ECM of the position of the clutch pedal or gear selector. if you look at the clutch pedal switch assy. above, you'll notice it is a dual switch type, one is used for the ECM and the other is used in the starting circuit.

On automatic transmissions, the neutral switch is also used as the 12-vdc activation voltage gate for the starter solenoid. It will not allow the start 12-vdc voltage to reach the starter solenoid, unless transmission speed selector is positioned in P or N. Different to the setup for manual transmissions, 12-vdc during start-ups will be present to the ECM as well, as shown in the two ECM and starter circuit diagrams below.




  • Engine idle control. The EEC uses the NSS circuit to control idle strategy to be used by the EEC. If the system is not able to ID a "in-neutral" condition, idle surging and rolling will occur.
  • NSS input is also an engine load determiner along with other inputs (TPS, MAF, VSS, etc).
  • Having a code 67 logged in the system can cause engine stalls in configurations with a manual transmission.
  • Its cruise control use has not changed.
  • Since NSS input is used to determine idle control strategy, its importance in the system is real. The presence of a code 67 failure will not allow the EEC to run the KOER self test for "saftey reasons.
  • If you still are hesitant to understand its importance for idle control, suggest you take a look at the documented video clip at http://sbftech.com/index.php/topic,7333.0.html .

Tools Required: (in addition to the generic tools)

  • Digital VOM or DMM
  • Wiring diagrams for your year Mustang
  • Vacuum diagram for your year Mustang

Testing Procedure:

1. If a code 67 is registered during KOEO, make sure transmission is in neutral and A/C is off...repeat KOEO self-test and check for code 67 to be registered....YES?..goto 2....NO?...code was caused by "operator error".

2. Make sure transmission is in neutral, A/C off, press clutch pedal and re-run a KOEO while maintaining the clutch pedal to the floor, check for code 67 to be registered....YES?...goto 3...NO?...need to check connection and wiring of gear switch at transmission....if OK...gear switch requires to be replaced.

3. This is where it gets uncomfortable.....check the clutch pedal switch under the dash board, identify the conector with the Lt. Blue/Yellow and Black/White wires and disconnect it. Install a jumper wire between the connector pins, and rerun a KOEO self-test...check for code 67 to be registered.....YES?...goto 4....NO?....replace pedal switch assembly.

4. Disconnect ECM, measure continuity from pin 30 to Lt. Blue/Yellow wire pin at the clutch switch, resistance should be less/equal to 5 ohms....YES?...goto 5.....NO?....pin 30 wire needs to be traced and repaired for an open.

5. ECM and pedal switch disconnected, measure continuity from Black/White wire pin at the pedal switch to pin 46 at the ECM connector resistance should be less/equal to 5 ohms....YES?...goto 6.....NO?....pin 46 wire needs to be traced and repaired for an open.

6. At this stage of the pinpoint, the only circuit left for testing is the A/C Clutch Signal (ACCS) at pin 10 in the ECM....ECM disconnected, Ign On, checke pin 10 voltage output to ground...voltage should be less than 1.0 vdc.....NO?...service short to power in ACCS wire.....YES?....ECM needs to be replaced.

Hope this helps someone....



Logged

ACRONYMS:
LUK  LMK  JIC  BTSTDTRT  YCYDYP  NFI-YTM  SPOBI, and the classic... DILLIGAS

'86 Mustang GT, X-303 cam, Holley DP 700, RG Tran., 289 Heads   Ford Smilie 2


Quote from: Joel5.0
The right to be stupid is inalienable for sure however, there is no such thing as a right to impose stupidity onto others
Great Thoughts will Overwhelm a Feeble Mind
There is never money to do it right, but there's always money to do it over.
Knowledge based on external evidence is unreliable.
He, who doesn't ask, does not deserve an answer.
A mind is like a parachute it only works when it is open.  (oldmanjoe)
If you can't explain it simply, you don't understand it well enough. (Albert Einstein)
Tuning on a Dyno for the track, is like swim practice in a bathtub.
I can explain it for you, but I can't understand it for you. (90lxcoupe)
The proof of understanding is the ability to explain it. (H. Torruella)
Ignorance is bliss, but stupidity is orgasmic.
Fraud and falsehood only dread examination. Truth invites it. (Samuel Johnson)
The chaotic resistance of the opponents leads to the conclusion that they are not prepared to meet the challenge. The problem is already much more psychological then technological. [Bojidar Djordjev]
Individuals are rational and humane... Crowds are reactionary and barbaric. (Jason)
The person who says it cannot be done should not interrupt the person doing it. –Chinese Proverb
Nothing sways the stupid more than arguments they can't understand - Cardinal de Retz
Pages: [1] Go Up Print 
« previous next »
Jump to:  



Powered by MySQL Powered by PHP Valid XHTML 1.0! Valid CSS!
Powered by SMF 1.1.21 | SMF © 2015, Simple Machines



408 Stroker