Engine Control - Self Test Revision
Article No. 85-5-21SHOP MANUAL REVISION - 5.0L - SELF TEST - ACCESSORY DRIVE
FORD 1985 MUSTANG
LINCOLN-MERCURY 1985 CAPRI
The cancellation of two-speed accessory drive has resulted in the possibility of false self-test codes.
The following codes are not valid and should be ignored.
Key On Engine Off Key Off Engine Running
(KOEO) (KOER)
HBV-22 HBV-22
ACHSS-24 ACHSS-24
Manual Clutch - 26 Grd. Sensor - 25
Manual Clutch - 26 TSAD - 38
Attached are revisions that should be incorporated in the 1985 Car Emission Diagnosis Shop Manual.
OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS: "INFORMATION ONLY"
Two Speed Accessory Drive - Self-Test
Quick Test
TSAD
3.0 KEY ON ENGINE OFF SELF-TEST
^ Deactivate Self-Test.
^ Start and run engine until upper radiator hose is hot and pressurized.
^ Turn engine off, wait 10 seconds
-Throttle depressed and held during test.
^ Ground STI, or latch STAR tester.
^ Ignition key to On. Do not start.
^ At completion of the 20 second test service code(s) will be outputted.*
^ Observe and record all service codes. One of the following outputs will occur:
RESULT ACTION TO TAKE
CODE FORMAT
ID PULSE SERVICE CODE
1 (0) 51, 61, 23 When these service codes are not displayed for Engine
Off, TSAD test indicates a pass.
1 (0) 51, 61, 23 Anyone of these service codes during Engine Off, TSAD
test indicates a fault. Go to Step (4.0). Ignore all other service codes.
NO CODE(S) OUTPUTTED Repeat Self-Test. If no service code(s) are
outputted, Go to Pinpoint Test Step (ZA-50).
*Star displays a 10 in place of a 1 for the single digit "ID pulse".
5.0 ENGINE RUNNING QUICK-TEST
^ Deactivate Self-Test.
^ Start and run engine to stable idle. (Upper hose hot and pressurized.)
^ Turn engine off, (key off).
Set-Up: Transmission in Neutral.
Ground STI.
Start engine and allow to idle: Clutch pedal out. Carburetor should be off high cam.
Read codes.
-The ID pulse will be outputted* -The system test will be performed (10-20 seconds) -Engine running service codes.
^ Observe and record all service codes. One of the following outputs will occur:
RESULT ACTION TO TAKE
CODE FORMAT
ID PULSE SERVICE CODE
1(0) 21, 23, 51, 61 When these service codes are displayed for Engine
Running TSAD test indicates a pass.
Any one of these service codes in Engine running TSAD
1(0) 21,23,51,61 test indicates a fault. Go to Test Step 6.0. Ignore all
other service codes.
NO CODES OUTPUTTED Repeat Self-Test. If no service code(s) are
outputted, Go to Pinpoint Test Step ZA-50.
*Star displays a 10 in place of a 1 for the single digit "ID pulse".
EEC IVEngine SupplementPassenger Car
Diagnostic By Symptom
TSAD
WARNING: To prevent the replacement of good components, Section 2 (Diagnostic Routines) must be addressed prior to entering TSAD Diagnostic by symptoms.
SYMPTOM ACTION TO TAKE
- Backfire (induction or exhaust)
- Surge at steady speed
- Engine noise (exhaust system) Pin Point Test ZB1
- Spark knock/pinging
- Overheating Pin Point Test ZB1, or ZC1
- Improperly operating A/C Pin Point Test ZC1
MCU-5.8L FBC, Police and Canadian Trailer Tow
Thermactor Check
Pinpoint
ZB
TEST STEP RESULT ACTION TO TAKE
NOTE: If vehicle demonstrates any of the listed concerns, go to Diagnostic By Symptom, Section 2 before performing the following test.
^ Backfire (Induction/Exhaust)
^ Surge at Steady Speed
^ Engine Noise (Exhaust System)
^ Spark Knock/Pinging
^ Overheating
^ Lower Idle Speeds
1. ^ Check the TAB vacuum solenoid output to make Vacuum present. GO to Diagnostic sure vacuum is not present when the solenoid Routine Section 2.
is energized.
^ Jump the TAB solenoid circuit 190 to Vacuum is not Go to step 2. ground. present.
^ Start engine, run at idle, for approximately 2 minutes.
2. ^ Measure the TAB solenoid resistance. Should R within range. Go to step 3. be between 50-110 ohms.
R not within range. REPLACE TAB
solenoid. Retest.
3.^ Key Off. R is more than 5 SERVICE circuit.
ohms.
^ Check circuits 687 and 190 for continuity R is 5 ohms or less. GO to Step 4. between the TAB solenoid and MCU module. Measure resistance.
4.^ Key Off. R is more than 1,000 REPLACE TSAD
ohms. module.
^ Check circuit 190 for a short to ground. R is 1,000 ohms SERVICE short.
Measure resistance. orless. Retest.
EEC IV - Pinpoint Tests - All Vehicles
WOT A/C Cutoff (WAC)
Check
Pinpoint
Test
ZC
TEST STEP RESULT ACTION TO TAKE
1. MEASURE WAC RELAY RESISTANCE
^ Key Off. Resistance is between CONNECT WAC
^ DVOM on 200 ohm scale. 50 and 70 ohms GO to 2.
^ Disconnect WAC relay connector and measure relay resistance. Resistance is less REPLACE WAC relay.
than 50 ohms or REPEAT Quick Test.
greater than 70 ohms
2. CHECK VOLTAGE OF V PWR CIRCUIT
^ Key On. Voltage reading is SERVICE harness
^ DVOM on 20V scale. less than 10.5V open circuit. REPEAT Quick Test.
^ Connect DVOM positive test lead to V PWR circuit and negative test lead to ground. Voltage reading is GO to 3.
^ Measure voltage on WAC relay V PWR circuit. 10.5V or greater
3. CHECK CONTINUITY OF WAC CIRCUIT
^ Key Off. Resistance readings SERVICE harness
^ Disconnect processor 60 Pin connector and are 5 ohms or greater open circuit. REPEAT inspect for damaged pins, corrosion, loose Quick Test.
wires. Service as necessary.
^ Connect Breakout box to harness. Leave Resistance reading is GO to 4. processor disconnected. less than 5 ohms
^ DVOM on 200 ohm scale.
^ Measure resistance between test Pin 44 and WAC circuit at harness connector.
TEST STEP RESULT ACTION TO TAKE
4. CHECK FOR SHORT TO GROUND
^ Key Off. Resistance readings SERVICE short to
^ Leave Breakout box installed and processor are less than 10,000 ground. REPEAT disconnected. ohms Quick Test.
^ DVOM on 200,000 ohm scale. Resistance readings GO to 5.
^ Measure resistance between test Pin 44 and are 10,000 ohms or test Pins 18 and 60. greater
5. CHECK FOR SHORT TO POWER
^ Key Off, wait 10 seconds. Resistance reading is REPLACE processor.
^ DVOM on 200,000 ohm scale. 10,000 ohms or REPEAT Quick Test. greater
^ Leave Breakout box installed and processor disconnected. Resistance reading is SERVICE short to
^ WAC solenoid disconnected. less than 10,000 ohms power. REPEAT
^ Measure resistance between test Pins 44 and Quick Test. test Pins 1 and 57.