Fleetwood V8-368 6.0L VIN 9 FI (1982)
Ignition Control Module: Technical Service Bulletins
Ignition System - Alternate On-Car HEI Module Test
Bulletin No.:
T-88-125
File in Group:
6E
Number:
60 Corp. Ref. No.: 816516
Date:
April '88
SUBJECT:
ALTERNATE ON-CAR HEI MODULE TEST
MODELS AFFECTED:
1982-1985 RWD DE VILLES AND FLEETWOOD BROUGHAMS 1985-1988 DE VILLES AND FLEETWOODS
1982-1988 ELDORADOS AND SEVILLES
During a recent analysis of inoperative ignition modules, a dealer submitted an alternate test procedure for diagnosing HEI ignition modules. The test
described below requires the use of only three jumper leads and a 12V electrical test light. It is presented here for use when an approved module tester,
such as the Kent-Moore tester J-24642-F, is damaged or otherwise unavailable. Use of an approved module tester is still recommended as the primary
diagnostic tool for ignition modules. Refer to Section 6E-C4, "Electronic Spark Timing (EST) System" and Section 6D4, "Ignition System" of the
appropriate model year Service Information Manual for additional information.
ON-CAR HEI MODULE TEST CADILLAC DFI MODELS ONLY
1.
Open the 4-way connector at the distributor wire harness.
2.
Using two jumper leads reconnect the distributor reference line, circuit 430 (purple/white) and the distributor ground, circuit 453 (black/red).
3.
Start the engine. A code "23" will set because the engine is running on Base Timing. If the engine will not start or stalls after start, refer to Chart
A-3 in Section 6E-A of the appropriate Service Information Manual.
4.
Connect a test light to 12V and probe pin "C", circuit 424 (tan/black), on the distributor side of the 4-way connector. Applying 12V to the bypass
line drives the HEI module into the EST mode. With the EST line, circuit 423 (white), open the engine should quit. If the engine quits, bypass
circuit operation of the HEI module is verified.
NOTE:
Battery and cranking motor must be operating correctly to reach proper rpm.
5.
On the distributor side of the 4-way connector jumper the EST line, circuit 423 (white) to distributor reference, circuit 430 (purple/white) . With
the test light still applying voltage to the bypass line circuit 424, start the engine. Engine operation verifies that the EST circuit in the HEI module
is operating normally.
6.
Remove the test light while the engine is running. If the engine quits, EST grounding in the HEI module is verified. When voltage is removed from
the bypass line, the module grounds the EST circuit internally. Since the EST line was jumpered to the distributor reference signal, the reference
signal will be grounded causing e engine to quit.
7.
If any of the above tests fail, inspect the distributor wiring for shorts or opens. If O.K., replace the ignition module.
8.
Remove all jumper leads and reconnect the distributor 4-way connector.
9.
Enter diagnostics and clear code 23.
