Rear ABS-
Flashes 1 Time-This code should not occur

Flashes 2 Times-Open Isolate Circuit

Flashes 3 Times-Open Dump Circuit

Flashes 4 Times/Red Brake Warning Light Illuminated-RABS Switch Closed

Flashes 5-Times-System dumps in 2wd (2wd & 4wd vehicles)-Condition occurs while making normal or hard stops. REAR BRAKE MAY LOCK

Flashes 6 Times-Sensor signal rapidly cuts in and out-Only occurs while driving

Flashes 7 Times-No Isolate Valve Test

Flashes 8 Times-No Dump Valve Test

Flashes 9 Times-High sensor resistance

Flashes 10 Times-Low sensor resistance

Flashes 11 Times-Stoplamp Switch Circuit Defective-Only occurs while driving above 35 MPH

Flashes 12 Times-Fluid level switch grounded during a RABS stop

Flashes 13 Times-Speed Processor Check

Flashes 14 Times-Program Check

Flashes 15 Times-Memory Failure

Flashes 16-16 or more flashes should not occur
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Applies to ALL 1987-1996 F-150 trucks-Except 1993-1996 Bronco Models
************************************************** *****

Diagnostic Trouble Codes for EEC-IV


Code 11-System Pass
Code 12-RPM Unable to reach upper test limit
Code 13-RPM Unable to reach lower test limit
Code 14-Pip circuit failure
Code 15-PCM Read only memory test failed
Code 16-PCM Keep alive memory test failed
Code 18-SPOUT Circuit open or spark angle word failure
Code 18-IDM Circuit failure or SPOUT circuit grounded
Code 19-Failure in PCM internal voltage
Code 21-ECT out of self test range
Code 22-BP sensor out of self test range
Code 22-BP sensor or MAP out of range
Code 23-TP sensor out of range
Code 24-ACT sensor out of self test range
Code 25-Knock not sensed during dynamic test
Code 26-TOT out of self test range
Code 26-TOT out of self test range (E-400)
Code 28- Loss of IDM, right side
Code 29-Insufficient input from Vehicle Speed Sensor
Code 31-PFE, EVP, or EVR out of test voltage range
Code 32-EVP voltage below closed limit
Code 33-EGR valve opening not detected
Code 34-EVP voltage above close limit
Code 35-PFE or EVP above close limit
Code 41-HEGO sensor circuit indicates system lean
Code 41-No HEGO switching detected
Code 42-HEGO sensor circuit indicate system rich

More in the book, just have to find more time......

-Wes