yo Rog,
Great!
DTCs 91/621, 92/622, 93/626, 94, 629, 641 and 652 indicate solenoid did not change state when requested by the Powertrain Control Module (PCM).
DTC 566 or 629 indicates the CCO or SS3/4-4/3 did not change state when requested by the PCM.
Possible causes:
read more @ http://www.thedieselstop.com/faq/9497faq/maint/vra/vra06108.htm#ppttc1
To help identify Self Test Output (STO), etc. see the Data Link Connector (DLC) diagram in Self-Test for Diagnostic Trouble Codes (DTC)s by my pal, BroncoJoe19
/monthly_05_2008/post-9476-1209779750.jpg">/monthly_05_2008/post-9476-1209779750_thumb.jpg
@ http://broncozone.com/topic/14269-code-reader/?&pid=74587&mode=threaded
=====
VSS is mounted on top of 8.8 rear diff.
Location pic
Source: by Shadofax
DTC 452 Erratic Harsh Shift; PSOM Operates Correctly; "...indicates that during the last 80 warm-up cycles, the PCM detected an error in the PSOM output signal. DTC 452 indicates the PCM detected an error in the PSOM output signal during the last 40 warm-up cycles. Pin-Point Test procedure EXACTLY from the Ford TSP/PCED.
Possible Causes:
Damaged Rear Anti-Lock Brake System. (See info below on
Damaged PSOM.
Damaged harness circuits.
Damaged PCM (Less Likely).
read more @ http://broncozone.com/topic/23677-limp-mode-and-dtc-452/
As I mentioned in another thread here; In place of the break out box, go to the EEC pin instead; for instance - Measure resistance between Test Pin 33 and Test Pin 40, 46 and 60 at the breakout box. Substitute EEC Connector for "break out box"
to help w/the Pin-Point Test see;
EEC IV Connector Pin Diagram
by Fireguy50 (Ryan M) at http://web.archive.org/web/201312291...ages/eec04.gif
EEC Connector Pin Outs LEGEND, Bronco & Ford Truck & Van: 4.9, 460, 5.0, 5.8; by Ryan M (Fireguy50) at
http://web.archive.org/web/201310290...ckpinouts.html
DTC 27, 29, 452, P0502, P0503, PO716, PO718; Insufficient input from VSS.; "...A more difficult problem to identify is a VSS that works, but sends out the wrong signal for a given vehicle speed. In some cases, a wrong reading from the VSS may still cause a code to be set. For example, if the VSS signal tells the computer the vehicle is traveling 60 miles an hour, but the throttle position sensor and MAP sensor tell the computer that the engine is idling, the computer will be confused. And a confused computer should set any of the following codes: Ford 27, 29, 452. On a vehicle that uses the VSS as a safety device, a defective sensor may send out a wrong "too fast" signal, shutting down fuel flow at the wrong time. Although this doesn’t happen often, it can be a difficult problem to identify. The customer will probably describe it as a random or intermittent sudden loss of power and poor performance, onlyto have the engine resume normal operation. Routine diagnostic checks of the engine in the shop won’t show any problem because there isn’t a problem with the engine or the ECM..."
Source: by wellsmfgcorp.com
DTC 452 Erratic Harsh Shift; Short Circuits, Common Locations TSB 95-02-11 on 94-95 Bronco & Trucks; SEE D: Code 452 - see Poss. Short Locations: 1. Driver's side A pillar trim screws may have been installed thru da 17K745 Sun Visor wire assy & .. bullet connector; 3. Scuff plate screws (driver's side) may pinch the 14A504 wire assy; 4. Dash Harness 14401 wire assy may be trapped/pinched between Half car beam & instrument panel attachment (repeated as #7. the wire harness may be pinched/shorted behind the dash where the 14401 wire assy may come in contact w/a sharp edge on dash panel wall. 5. shift cable assy near tranny may chaf the wire harness; the wire harness; 7. repeated above..brake pedal-to-dash panel wall weld.
RABS Codes
Whenever the yellow REAR ABS light comes on during normal operation, a flashout code may be obtained to aid in problem diagnosis. If the vehicle is shut off before the code is read from a RABS-I module, the code will be lost. In some cases, the code may reappear when the vehicle is restarted. In other cases, the vehicle may have to be driven to reproduce the problem and, if the problem was associated with an intermittent condition, it may be difficult to reproduce. Therefore, whenever possible, it is recommended that the code be read before the vehicle is shut off. RABS II modules have been designed with Keep Alive Memory to preserve stored codes during key-off, and are to be used to service all prior year RABS I systems, except for 1987 and 1988 Bronco II vehicles.
WARNING: PLACE BLOCKS BEHIND THE REAR WHEELS AND IN FRONT OF THE FRONT WHEELS TO PREVENT THE VEHICLE FROM MOVING WHILE THE FLASHOUT CODE IS BEING TAKEN.
NOTE: If the red BRAKE light is also on, due to a grounding of the fluid level circuit (perhaps low brake fluid), no flashout code will be flashed and the REAR ABS light will remain on steadily. Top up the brake master cylinder reservoir before attempting to read codes.
NOTE: If there is more than one system fault, only the first recognized flashout code may be obtained.
Obtaining the Flashout Code
A flashout code may be obtained only when the yellow REAR ABS light is on. No code will be flashed if the system is OK. There are certain faults (those associated with the fluid level switch or loss of power to the module) that will cause the system to be deactivated and the REAR ABS light to be illuminated, but will not provide a diagnostic flashout code.
Before obtaining the flashout code, drive the vehicle to a level area, and place the shift lever in PARK for automatic transmissions and NEUTRAL for manual transmissions.
Notice whether the red BRAKE light is on or not (for future reference) and then apply the parking brake.
WARNING: PLACE BLOCKS BEHIND THE REAR WHEELS AND IN FRONT OF THE FRONT WHEELS TO PREVENT THE VEHICLE FROM MOVING WHILE THE FLASHOUT CODE IS BEING TAKEN.
To obtain the flashout code, locate the RABS diagnostic connector (with the Bk/Or wire); on 92-93, it's above the right end of the glove box bottom corner, inside the dash; on earlier trucks, it's between the brake & e-brake pedals near the firewall. Separate the R wire's connector half, turn the key to RUN, and attach a jumper wire to Bk/Or. Momentarily ground the Bk/OR jumper to the chassis (the lighter socket shell). When the ground is made and then broken, the REAR ABS light should begin to flash.
NOTE: If the red BRAKE light was on (as noticed before the parking brake was applied), the problem may be with the low fluid level circuit and, in this case, no flashout code will be flashed and the light will remain on steadily.
The code consists of a number of short flashes and ends with a long flash. Count the short flashes and include the following long flash in the count to obtain the code number. For example, three short flashes followed by one long flash indicates Flashout Code Four. The code will continue to repeat itself until the key is turned off. It is recommended that the code be verified by reading it several times. In addition, the first code flashed may be too short because it may have been started in the middle. It should be ignored.
After ALL codes have been read & repaired, clear the memory by turning the key off while the connector halves are separated, then reconnect the halves.
GL on the RR job!!!!!!!!!!!!!!!!!!!
Great!
DTCs 91/621, 92/622, 93/626, 94, 629, 641 and 652 indicate solenoid did not change state when requested by the Powertrain Control Module (PCM).
DTC 566 or 629 indicates the CCO or SS3/4-4/3 did not change state when requested by the PCM.
Possible causes:
- Damaged solenoid/assembly.
- Open or shorted harness (internal/external).
- Damaged PCM.
- Disconnect electrical connector on the speed control servo, if equipped.
- VOM/DVOM on 20 volt scale.
- Connect negative test lead to STO circuit at Data Link Connector (DLC) and meter positive test lead to B+.
- Jumper STI circuit to SIG RTN at the DLC.
- Perform Key On Engine Off Self-Test until Continuous Memory DTC have been displayed.
- VOM/DVOM will indicate less than 1.0 volt when test is complete.
- Depress and release throttle.
read more @ http://www.thedieselstop.com/faq/9497faq/maint/vra/vra06108.htm#ppttc1
To help identify Self Test Output (STO), etc. see the Data Link Connector (DLC) diagram in Self-Test for Diagnostic Trouble Codes (DTC)s by my pal, BroncoJoe19
/monthly_05_2008/post-9476-1209779750.jpg">/monthly_05_2008/post-9476-1209779750_thumb.jpg
@ http://broncozone.com/topic/14269-code-reader/?&pid=74587&mode=threaded
=====
VSS is mounted on top of 8.8 rear diff.
Location pic
Source: by Shadofax
DTC 452 Erratic Harsh Shift; PSOM Operates Correctly; "...indicates that during the last 80 warm-up cycles, the PCM detected an error in the PSOM output signal. DTC 452 indicates the PCM detected an error in the PSOM output signal during the last 40 warm-up cycles. Pin-Point Test procedure EXACTLY from the Ford TSP/PCED.
Possible Causes:
Damaged Rear Anti-Lock Brake System. (See info below on
Damaged PSOM.
Damaged harness circuits.
Damaged PCM (Less Likely).
read more @ http://broncozone.com/topic/23677-limp-mode-and-dtc-452/
As I mentioned in another thread here; In place of the break out box, go to the EEC pin instead; for instance - Measure resistance between Test Pin 33 and Test Pin 40, 46 and 60 at the breakout box. Substitute EEC Connector for "break out box"
to help w/the Pin-Point Test see;
EEC IV Connector Pin Diagram
by Fireguy50 (Ryan M) at http://web.archive.org/web/201312291...ages/eec04.gif
EEC Connector Pin Outs LEGEND, Bronco & Ford Truck & Van: 4.9, 460, 5.0, 5.8; by Ryan M (Fireguy50) at
http://web.archive.org/web/201310290...ckpinouts.html
DTC 27, 29, 452, P0502, P0503, PO716, PO718; Insufficient input from VSS.; "...A more difficult problem to identify is a VSS that works, but sends out the wrong signal for a given vehicle speed. In some cases, a wrong reading from the VSS may still cause a code to be set. For example, if the VSS signal tells the computer the vehicle is traveling 60 miles an hour, but the throttle position sensor and MAP sensor tell the computer that the engine is idling, the computer will be confused. And a confused computer should set any of the following codes: Ford 27, 29, 452. On a vehicle that uses the VSS as a safety device, a defective sensor may send out a wrong "too fast" signal, shutting down fuel flow at the wrong time. Although this doesn’t happen often, it can be a difficult problem to identify. The customer will probably describe it as a random or intermittent sudden loss of power and poor performance, onlyto have the engine resume normal operation. Routine diagnostic checks of the engine in the shop won’t show any problem because there isn’t a problem with the engine or the ECM..."
Source: by wellsmfgcorp.com
DTC 452 Erratic Harsh Shift; Short Circuits, Common Locations TSB 95-02-11 on 94-95 Bronco & Trucks; SEE D: Code 452 - see Poss. Short Locations: 1. Driver's side A pillar trim screws may have been installed thru da 17K745 Sun Visor wire assy & .. bullet connector; 3. Scuff plate screws (driver's side) may pinch the 14A504 wire assy; 4. Dash Harness 14401 wire assy may be trapped/pinched between Half car beam & instrument panel attachment (repeated as #7. the wire harness may be pinched/shorted behind the dash where the 14401 wire assy may come in contact w/a sharp edge on dash panel wall. 5. shift cable assy near tranny may chaf the wire harness; the wire harness; 7. repeated above..brake pedal-to-dash panel wall weld.
RABS Codes
Whenever the yellow REAR ABS light comes on during normal operation, a flashout code may be obtained to aid in problem diagnosis. If the vehicle is shut off before the code is read from a RABS-I module, the code will be lost. In some cases, the code may reappear when the vehicle is restarted. In other cases, the vehicle may have to be driven to reproduce the problem and, if the problem was associated with an intermittent condition, it may be difficult to reproduce. Therefore, whenever possible, it is recommended that the code be read before the vehicle is shut off. RABS II modules have been designed with Keep Alive Memory to preserve stored codes during key-off, and are to be used to service all prior year RABS I systems, except for 1987 and 1988 Bronco II vehicles.
WARNING: PLACE BLOCKS BEHIND THE REAR WHEELS AND IN FRONT OF THE FRONT WHEELS TO PREVENT THE VEHICLE FROM MOVING WHILE THE FLASHOUT CODE IS BEING TAKEN.
NOTE: If the red BRAKE light is also on, due to a grounding of the fluid level circuit (perhaps low brake fluid), no flashout code will be flashed and the REAR ABS light will remain on steadily. Top up the brake master cylinder reservoir before attempting to read codes.
NOTE: If there is more than one system fault, only the first recognized flashout code may be obtained.
Obtaining the Flashout Code
A flashout code may be obtained only when the yellow REAR ABS light is on. No code will be flashed if the system is OK. There are certain faults (those associated with the fluid level switch or loss of power to the module) that will cause the system to be deactivated and the REAR ABS light to be illuminated, but will not provide a diagnostic flashout code.
Before obtaining the flashout code, drive the vehicle to a level area, and place the shift lever in PARK for automatic transmissions and NEUTRAL for manual transmissions.
Notice whether the red BRAKE light is on or not (for future reference) and then apply the parking brake.
WARNING: PLACE BLOCKS BEHIND THE REAR WHEELS AND IN FRONT OF THE FRONT WHEELS TO PREVENT THE VEHICLE FROM MOVING WHILE THE FLASHOUT CODE IS BEING TAKEN.
To obtain the flashout code, locate the RABS diagnostic connector (with the Bk/Or wire); on 92-93, it's above the right end of the glove box bottom corner, inside the dash; on earlier trucks, it's between the brake & e-brake pedals near the firewall. Separate the R wire's connector half, turn the key to RUN, and attach a jumper wire to Bk/Or. Momentarily ground the Bk/OR jumper to the chassis (the lighter socket shell). When the ground is made and then broken, the REAR ABS light should begin to flash.
NOTE: If the red BRAKE light was on (as noticed before the parking brake was applied), the problem may be with the low fluid level circuit and, in this case, no flashout code will be flashed and the light will remain on steadily.
The code consists of a number of short flashes and ends with a long flash. Count the short flashes and include the following long flash in the count to obtain the code number. For example, three short flashes followed by one long flash indicates Flashout Code Four. The code will continue to repeat itself until the key is turned off. It is recommended that the code be verified by reading it several times. In addition, the first code flashed may be too short because it may have been started in the middle. It should be ignored.
After ALL codes have been read & repaired, clear the memory by turning the key off while the connector halves are separated, then reconnect the halves.
GL on the RR job!!!!!!!!!!!!!!!!!!!
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