Engine Controls - No Start, Stalls or Surges/DTCs
BULLETIN NO.: 96-T-58ISSUE DATE: October, 1996
GROUP/SEQ. NO.: Engine-12
CORPORATION NO.: 686004
SUBJECT:
Engine Cranks but will not Start, Engine Starts then Stalls, or Engine
Surges or Stalls During Light Throttle Conditions and/or Engine Runs
Rough, with Possible DTCs in PCM Memory (Repair Chafed Wire in
Engine Harness)
MODELS AFFECTED:
1995 and 1996 Saturns built up to and including VIN TZ360348
CONDITION:
Engine cranks but will not start, engine starts then stalls, or engine surges or stalls during a light throttle condition and/or engine runs rough. In some cases, the condition may be accompanied by one or more of the following diagnostic trouble codes (DTCs) or Information Flags:
^ 1995 vehicles - DTCs 22, 32, and/or 34, 45 Information Flags 54 and/or 76
^ 1996 vehicles - DTCs P0107, P0122, P0201, P0202, P0203, P0204, P0300, P0301, P0302, P0303, P0304, P1107, P1122, P1406, P1599, P0172 and/or P1635
CAUSE:
The conditions may be caused by one or more wires being located outside of the wiring harness conduit and chafing against the intake manifold, causing the insulation on the wire(s) to rub off. If the insulation on the wire(s) rubs off, it will cause a short-to-ground in that particular circuit(s). A short-to-ground in a circuit(s) will cause one or more of the following conditions listed on the next page:
^ Engine cranks but will not start - The injector B+ circuit may have a chafe in the insulation, causing a short-to-ground. In some cases, the short-to-ground may cause the injector fuse to open. If a fuel injector B+ circuit shorts-to-ground, none of the fuel injectors will energize, preventing fuel delivery to the engine. If the injector B+ circuit shorts-to-ground, DTCs P0201, P0202, P0203, P0204, and/or P1599 may be stored in PCM memory.
^ Engine starts then stalls or engine surges or stalls during light throttle condition - Manifold absolute pressure (MAP) sensor reference voltage circuits may have a chafe in the insulation, causing a short-to-ground. This short-to-ground may cause the engine to start then stall or surge, or stall during a light throttle condition. If this reference voltage circuit shorts-to-ground, DTCs 22, 32 or 34, or Information Flags 54 and 76 for 1995 vehicles; or DTCs P0107, P0122, P1107, P1122, P1406, P1599 and/or P1635, for 1996 vehicles may be stored in PCM memory.
^ Engine misfire, fuel injector DTCs or engine runs rough - The fuel injector ground circuits may have a chafe in the insulation causing short-to-ground. This short-to-ground may cause the fuel injector to deliver fuel to the engine when not required. If the injector ground circuit(s) short-to-ground DTC 45 for 1995 vehicles; or DTCs P1599, P0172, P0201, P0202, P0203, P0204, P0300, P0301, P0302, P0303 and/or P0304 for 1996 vehicles may be stored in PCM memory.
CORRECTION
Refer to the following procedure to verify and repair the condition.
PROCEDURE
1. Refer to the illustrations on the facing page for location of where wires may chafe against intake manifold.
2. Check wiring conduit to see if any wire(s) are outside of the conduit.
^ If any wire(s) are located outside of conduit, proceed to next step.
^ If there are no wires located outside of conduit, refer to diagnostic procedure in the "1995 Engine Controls Service Manual" or "1996 Revised Powertrain Controls Service Manual" (depending on model year of vehicle).
3. If wire(s) are located outside of the conduit, disconnect wires from injectors and MAP sensor and pull harness down through intake manifold runners. Completely remove the wire(s) from the conduit and check for chafing.
^ If chafing is evident, use Saturn approved Packard Crimp and Seal splices (Salmon/Pink [OTC # 217670]) found in the Saturn wire repair kit and service procedures in the "Electrical Service Manual," and repair damaged circuit(s).
^ If there is no chafing to any of the wires, refer to diagnostic procedure in the "1995 Engine Controls Service Manual" or "1996 Revised Powertrain Controls Service Manual" (depending on model year of vehicle).
4. To prevent any possible further damage, use a high - quality electrical tape and wrap the entire wiring harness in the damaged area prior to installing the harness back into the conduit.
5. Replace the harness inside the conduit and spiral tape the conduit with electrical tape.
6. If any of the injector ground circuits were chafed at the intake manifold:
a. After the wire(s) have been repaired, change engine oil and filter. (The engine oil may have been diluted with fuel.)
b. Perform exhaust back pressure test to check for possible clogged catalytic converter. (Refer to appropriate year "Engine/Fuel/Air Intake/Exhaust Service Manual" for exhaust back pressure procedure.)
PARTS REQUIREMENTS:
OTC 21760 Crimp and Seal Splices (Salmon/Pink)
CLAIM INFORMATION:
To receive credit for this repair during the warranty coverage period, submit a claim through the Saturn Dealer System as shown.